Forests

1628 KiB

Open AccessArticle

Effect of Timber Harvest Intensities and Fertilizer Application on Stocks of Soil C, N, P, and S

by Marcella L.C. Menegale, Jose Henrique T. Rocha, Robert Harrison, Jose Leonardo de M. Goncalves, Rodrigo F. Almeida, Marisa De C. Piccolo, Ayeska Hubner, Jose Carlos Arthur Junior, Alexandre De Vicente Ferraz, Jason N. James and Stephani Michelsen-Correa

Forests 2016, 7(12), 319; https://doi.org/10.3390/f7120319 - 21 Dec 2016

Cited by 17 | Viewed by 4970

Abstract

The purpose of this study was to determine the stocks of available P and S, total N, and oxidizable C at depth in an Oxisol cultivated with Eucalyptus in Brazil following different timber harvest intensities and fertilizer application over 12 years. The harvest [...] Read more.

The purpose of this study was to determine the stocks of available P and S, total N, and oxidizable C at depth in an Oxisol cultivated with Eucalyptus in Brazil following different timber harvest intensities and fertilizer application over 12 years. The harvest regimes considered were (i) conventional stem-only harvest (all forest residues were maintained on the soil); (ii) whole-tree harvest (only litter was maintained on the soil—all slash, stemwood, and bark were removed); and (iii) whole-tree harvest + litter layer removal. The site was planted in 2004 considering three timber harvest intensities, some with and some without N and P fertilization. In 2012 the experiment was reinstalled, and all the treatments were reapplied in the each plot. From 2004 to 2016, nutrient accumulation and soil N, P, and S stocks were assessed in the 0–20 cm layer. Also in 2016, soil N, P, S, and oxidizable C stocks were measured to 2 m depth. For each treatment, the net balance of N, P, and S were calculated from soil stocks and harvest outputs during two forest rotations. A reduction in all nutrient stocks was observed in the 0–20 cm layer for all treatments. For N, this reduction was 20% smaller in the stem-only harvest treatment and 40% higher when no N fertilizer was applied, when compared to other treatments. Stem-only harvest treatment was observed to reduce the loss of N, P, and S due to harvest by 300, 30, and 25 kg·ha⁻¹, respectively, when compared to the whole-tree harvest + litter layer removal treatment. Full article

(This article belongs to the Special Issue Nutrient Cycling and Plant Nutrition in Forest Ecosystems)

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2276 KiB

Open AccessArticle

SOM and Biomass C Stocks in Degraded and Undisturbed Andean and Coastal Nothofagus Forests of Southwestern South America

by Francis Dube and Neal B. Stolpe

Forests 2016, 7(12), 320; https://doi.org/10.3390/f7120320 - 20 Dec 2016

Cited by 8 | Viewed by 6213

Abstract

Grazing and over-exploitation can severely degrade soil in native forests. Considering that productivity in ecosystems is related to soil organic matter (SOM) content and quality, the objectives of this study were to: (1) determine the influence of degraded (DEF), partly-degraded (PDF), and undisturbed [...] Read more.

Grazing and over-exploitation can severely degrade soil in native forests. Considering that productivity in ecosystems is related to soil organic matter (SOM) content and quality, the objectives of this study were to: (1) determine the influence of degraded (DEF), partly-degraded (PDF), and undisturbed (UNF) Nothofagus forests on the stocks of carbon (C) in tree biomass and SOM; (2) evaluate fractions of SOM as indicators of sustainable management; and (3) use the Century model to determine the potential gains of soil organic C (SOC). The forests are located in the Andes and Coastal mountains of southern Chile. The SOM was fractionated to separate the light fraction (LF), macroaggregates (>212 µm), mesoaggregates (212–53 µm), and microaggregates (<53 µm). In two measurement periods, the SOC stocks at 0–20 cm and 20–40 cm depths in macroaggregates were on average 100% higher in the Andean UNF, and SOC was over twice as much at 20–40 cm depth in Andean DEF. Century simulations showed that improved silvopastoral management would gradually increase total SOC in degraded soils of both sites, especially the Ultisol with a 15% increase between 2016 and 2216 (vs. 7% in the Andisol). Greater SOC in macroaggregates (p < 0.05) of UNF indicate a condition of higher sustainability and better management over the years. Full article

(This article belongs to the Collection Forests Carbon Fluxes and Sequestration)

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Open AccessArticle

Identification and Target Prediction of MicroRNAs in Ulmus pumila L. Seedling Roots under Salt Stress by High-Throughput Sequencing

by Jianfeng Zhu, Xiuyan Yang, Zhengxiang Liu and Huaxin Zhang

Forests 2016, 7(12), 318; https://doi.org/10.3390/f7120318 - 20 Dec 2016

Cited by 5 | Viewed by 5140

Abstract

MicroRNAs (miRNAs) are a class of endogenous small RNAs with important roles in plant growth, development, and environmental stress responses. Ulmus pumila L., a deciduous broadleaved tree species of northern temperate regions, is widely distributed in central and northern Asia and has important [...] Read more.

MicroRNAs (miRNAs) are a class of endogenous small RNAs with important roles in plant growth, development, and environmental stress responses. Ulmus pumila L., a deciduous broadleaved tree species of northern temperate regions, is widely distributed in central and northern Asia and has important economic and ecological value. With the spread and aggravation of soil salinization, salt stress has become a major abiotic stress affecting the normal growth and development of U. pumila. However, the influence of salt stress on U. pumila miRNA expression has not been investigated. To identify miRNAs and predict their target mRNA genes under salt stress, three small RNA libraries were generated and sequenced from roots of U. pumila seedlings treated with various concentrations of NaCl corresponding to no salt stress, light short-term salt stress, and medium-heavy long-term salt stress. Integrative analysis identified 254 conserved miRNAs representing 29 families and 49 novel miRNAs; 232 potential targets of the miRNAs were also predicted. Expression profiling of miRNAs between libraries was performed, and the expression of six miRNAs was validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Our findings provide an overview of potential miRNAs and corresponding targets involved in regulating U. pumila salt defense responses. These results lay the foundation for further research into molecular mechanisms involved in salt stress resistance in U. pumila and other Ulmaceae species. Full article

(This article belongs to the Special Issue Genomics for Sustainable Forestry - Selected Papers from IUFRO Genomics and Forest Tree Genetics Conference)

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Open AccessReview

Global Ecological Signpost, Local Reality: The Moraballi Creek Studies in Guyana and What Happened Afterwards

by Janette Bulkan and John Palmer

Forests 2016, 7(12), 317; https://doi.org/10.3390/f7120317 - 15 Dec 2016

Cited by 6 | Viewed by 6067

Abstract

There is a common assumption that when sustainable forest management (SFM) is not practised the reasons are usually a lack of knowledge or lack of training in applying those techniques. We trace the intermittent development of techniques for SFM in the tropical rainforest [...] Read more.

There is a common assumption that when sustainable forest management (SFM) is not practised the reasons are usually a lack of knowledge or lack of training in applying those techniques. We trace the intermittent development of techniques for SFM in the tropical rainforest of Guyana (South America), beginning with the classical observational ecology at Moraballi Creek in 1929. We reference the deliberate lack of application of SFM in spite of access to science-based information and repeated training. In this country, a precarious political democracy is destabilised by the gigantic profits from illegal logging and log trading which support corruption in the sector and generally across regulatory systems. The highest rate of graduate emigration in the world contributes to the difficulty of creating the core of moral leadership required to rise above the local tradition of under-the-table negotiation in place of the rule of law. Full article

(This article belongs to the Special Issue Interplay of Human and Natural Disturbances on Pattern and Process in Forest Ecosystems)

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1637 KiB

Open AccessArticle

Effects of Different Ectomycorrhizal Fungal Inoculates on the Growth of Pinus tabulaeformis Seedlings under Greenhouse Conditions

by Nan Lu, Meng Yu, Ming Cui, Zijing Luo, Yue Feng, Sen Cao, Yuhan Sun and Yun Li

Forests 2016, 7(12), 316; https://doi.org/10.3390/f7120316 - 14 Dec 2016

Cited by 22 | Viewed by 5077

Abstract

The tree species Pinus tabulaeformis Carr. (P. tabulaeformis) is commonly planted in China due to its economic and ecological value. In order to identify one or more ectomycorrhizal (ECM) fungal species for future P. tabulaeformis afforestation, we investigated the effects of [...] Read more.

The tree species Pinus tabulaeformis Carr. (P. tabulaeformis) is commonly planted in China due to its economic and ecological value. In order to identify one or more ectomycorrhizal (ECM) fungal species for future P. tabulaeformis afforestation, we investigated the effects of five ECM fungal species: Laccaria laccata, Boletus edulis, Gomphidius viscidus, Suillus grevillei, and Suillus luteus on the growth of P. tabulaeformis seedlings under greenhouse conditions. The growth parameters of P. tabulaeformis seedlings were evaluated 90 days following fungal colonisation. The majority of seedlings were significantly affected by ECM inoculation. Mycorrhizal inoculated seedlings were taller, had more lateral roots, and a greater biomass compared with the non-mycorrhizal (CK) seedlings. With the exception of G. viscidus, inoculated seedlings exhibited higher phosphorus, potassium, and nitrogen content compared with the CK seedlings. In addition, ECM colonisation increased the enzymatic activity of catalase, acidic phosphatase, protease, and the urease content in the rhizosphere soil. Our study showed that Laccaria laccata, Suillus grevillei, and Suillus luteus may be useful for improving the growth and cultivation of P. tabulaeformis seedlings. Furthermore, we observed that S. luteus inoculation increased the gas exchange parameters of P. tabulaeformis seedlings under field conditions. Full article

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Open AccessArticle

Multiple Patterns of Forest Disturbance and Logging Shape Forest Landscapes in Paragominas, Brazil

by Isabelle Tritsch, Plinio Sist, Igor Da Silva Narvaes, Lucas Mazzei, Lilian Blanc, Clément Bourgoin, Guillaume Cornu and Valery Gond

Forests 2016, 7(12), 315; https://doi.org/10.3390/f7120315 - 13 Dec 2016

Cited by 31 | Viewed by 7009

Abstract

In the Brazilian Amazon, multiple logging activities are undergoing, involving different actors and interests. They shape a disturbance gradient bound to the intensity and frequency of logging, and forest management techniques. However, until now, few studies have been carried out at the landscape [...] Read more.

In the Brazilian Amazon, multiple logging activities are undergoing, involving different actors and interests. They shape a disturbance gradient bound to the intensity and frequency of logging, and forest management techniques. However, until now, few studies have been carried out at the landscape scale taking into account these multiple types of logging and this disturbance gradient. Here we address this issue of how to account for the multiple logging activities shaping the current forest landscape. We developed an inexpensive and efficient remote sensing methodology based on Landsat imagery to detect and track logging activity based on the monitoring of canopy openings. Then, we implemented a set of remote sensing indicators to follow the different trajectories of forest disturbance through time. Using these indicators, we emphasized five major spatial and temporal disturbance patterns occurring in the municipality of Paragominas (State of Pará, Brazilian Amazon), from well-managed forests to highly over-logged forests. Our disturbance indicators provide observable evidence for the difference between legal and illegal patterns, with some illegal areas having suffered more than three explorations in fifteen years. They also clearly underlined the efficiency of Reduced Impact Logging (RIL) techniques applied under Forest Stewardship Council (FSC) guidelines to reduce the logging impacts in terms of canopy openings. For these reasons, we argue the need to promote legal certified logging to conserve forests, as without them, many actors mine the forest resources without any concerns for future stocks. Finally, our remote tracking methodology, which produces easy to interpret disturbance indicators, could be a real boon to forest managers, including for conservationists working in protected areas and stakeholders dealing with international trade rules such as RBUE (Wood regulation of European Union) or FLEGT (Forest Law for Enforcement, Governance and Trade). Full article

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Open AccessFeature PaperCommentary

Lessons from Research for Sustainable Development and Conservation in Borneo

by William F. Laurance

Forests 2016, 7(12), 314; https://doi.org/10.3390/f7120314 - 11 Dec 2016

Cited by 9 | Viewed by 7105

Abstract

I present a brief synopsis of six key lessons provided by research on forest ecology and conservation, focusing particularly on the Malaysian state of Sabah in northeastern Borneo. These lessons are generalizable to other contexts, especially for tropical developing nations, where surviving forests [...] Read more.

I present a brief synopsis of six key lessons provided by research on forest ecology and conservation, focusing particularly on the Malaysian state of Sabah in northeastern Borneo. These lessons are generalizable to other contexts, especially for tropical developing nations, where surviving forests are under growing pressures from a range of human activities. Full article

(This article belongs to the Special Issue Interplay of Human and Natural Disturbances on Pattern and Process in Forest Ecosystems)

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Open AccessArticle

A Dominant Voice amidst Not Enough People: Analysing the Legitimacy of Mexico’s REDD+ Readiness Process

by Jovanka Špirić, Esteve Corbera, Victoria Reyes-García and Luciana Porter-Bolland

Forests 2016, 7(12), 313; https://doi.org/10.3390/f7120313 - 10 Dec 2016

Cited by 11 | Viewed by 7315

Abstract

In the development of national governance systems for Reducing Emissions from Deforestation and forest Degradation (REDD+), countries struggle with ensuring that decision-making processes include a variety of actors (i.e., input legitimacy) and represent their diverse views in REDD+ policy documents (i.e., output legitimacy). [...] Read more.

In the development of national governance systems for Reducing Emissions from Deforestation and forest Degradation (REDD+), countries struggle with ensuring that decision-making processes include a variety of actors (i.e., input legitimacy) and represent their diverse views in REDD+ policy documents (i.e., output legitimacy). We examine these two dimensions of legitimacy using Mexico’s REDD+ readiness process during a four-year period (2011–2014) as a case study. To identify REDD+ actors and how they participate in decision-making we used a stakeholder analysis; to assess actors’ views and the extent to which these views are included in the country’s official REDD+ documents we conducted a discourse analysis. We found low level of input legitimacy in so far as that the federal government environment agencies concentrate most decision-making power and key land-use sectors and local people’s representatives are absent in decision-making forums. We also observed that the REDD+ discourse held by government agencies and both multilateral and international conservation organisations is dominant in policy documents, while the other two identified discourses, predominantly supported by national and civil society organisations and the academia, are partly, or not at all, reflected in such documents. We argue that Mexico’s REDD+ readiness process should become more inclusive, decentralised, and better coordinated to allow for the deliberation and institutionalisation of different actors’ ideas in REDD+ design. Our analysis and recommendations are relevant to other countries in the global South embarking on REDD+ design and implementation. Full article

(This article belongs to the Special Issue REDD+ Crossroads Post Paris: Politics, Lessons and Interplays)

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1988 KiB

Open AccessArticle

Foliage Chemistry of Pinus baksiana in the Athabasca Oil Sands Region, Alberta, Canada

by Bernadette C. Proemse, Doug G. Maynard and Bernhard Mayer

Forests 2016, 7(12), 312; https://doi.org/10.3390/f7120312 - 8 Dec 2016

Cited by 9 | Viewed by 4812

Abstract

Industrial emissions in the Athabasca Oil Sands Region (AOSR), Alberta, Canada, have caused concerns about the effect of oil sands operations on the surrounding terrestrial environments, including jack pine (Pinus banksiana Lamb.) stands. We collected jack pine needles from 19 sites in [...] Read more.

Industrial emissions in the Athabasca Oil Sands Region (AOSR), Alberta, Canada, have caused concerns about the effect of oil sands operations on the surrounding terrestrial environments, including jack pine (Pinus banksiana Lamb.) stands. We collected jack pine needles from 19 sites in the AOSR (13–128 km from main operations) for foliar chemical analyses to investigate the environmental impact on jack pine. Pine needles from three age classes, the current annual growth (CAG, 2011), one year and two year old pine needles, were collected. Samples were analyzed for total carbon (TC), nitrogen (TN), and sulfur (TS), inorganic S (SO₄-S), base cations (Ca, Mg, Na), and other elements (B, Cu, Fe, Mn, P, Zn); CAG needles were also analyzed for their nitrogen and carbon isotopic compositions. Only TN, TS, Ca, B, Zn, and Fe contents showed weak but significant increases with proximity to the major oil sands operations. C and N isotopic compositions showed no trend with distance or TC and TN contents. Total S contents in CAG of pine foliage increased significantly with proximity to the main industrial operation while foliar inorganic S to organic S ratios (SO₄-S/S_org) ranged consistently between 0.13 and 0.32, indicating low to moderately high S loading. Hence, this study suggests some evidence of uptake of S emissions in close proximity to anthropogenic sources, although the reported values have not reached a level of environmental concern. Full article

(This article belongs to the Special Issue Forest Growth Response to Environmental Stress)

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Open AccessArticle

Predictive Modeling of Black Spruce (Picea mariana (Mill.) B.S.P.) Wood Density Using Stand Structure Variables Derived from Airborne LiDAR Data in Boreal Forests of Ontario

by Bharat Pokharel, Art Groot, Douglas G. Pitt, Murray Woods and Jeffery P. Dech

Forests 2016, 7(12), 311; https://doi.org/10.3390/f7120311 - 8 Dec 2016

Cited by 6 | Viewed by 5637

Abstract

Our objective was to model the average wood density in black spruce trees in representative stands across a boreal forest landscape based on relationships with predictor variables extracted from airborne light detection and ranging (LiDAR) point cloud data. Increment core samples were collected [...] Read more.

Our objective was to model the average wood density in black spruce trees in representative stands across a boreal forest landscape based on relationships with predictor variables extracted from airborne light detection and ranging (LiDAR) point cloud data. Increment core samples were collected from dominant or co-dominant black spruce trees in a network of 400 m² plots distributed among forest stands representing the full range of species composition and stand development across a 1,231,707 ha forest management unit in northeastern Ontario, Canada. Wood quality data were generated from optical microscopy, image analysis, X-ray densitometry and diffractometry as employed in SilviScan™. Each increment core was associated with a set of field measurements at the plot level as well as a suite of LiDAR-derived variables calculated on a 20 × 20 m raster from a wall-to-wall coverage at a resolution of ~1 point m⁻². We used a multiple linear regression approach to identify important predictor variables and describe relationships between stand structure and wood density for average black spruce trees in the stands we observed. A hierarchical classification model was then fitted using random forests to make spatial predictions of mean wood density for average trees in black spruce stands. The model explained 39 percent of the variance in the response variable, with an estimated root mean square error of 38.8 (kg·m⁻³). Among the predictor variables, P20 (second decile LiDAR height in m) and quadratic mean diameter were most important. Other predictors describing canopy depth and cover were of secondary importance and differed according to the modeling approach. LiDAR-derived variables appear to capture differences in stand structure that reflect different constraints on growth rates, determining the proportion of thin-walled earlywood cells in black spruce stems, and ultimately influencing the pattern of variation in important wood quality attributes such as wood density. A spatial characterization of variation in a desirable wood quality attribute, such as density, enhances the possibility for value chain optimization, which could allow the forest industry to be more competitive through efficient planning for black spruce management by including an indication of suitability for specific products as a modeled variable derived from standard inventory data. Full article

(This article belongs to the Special Issue LiDAR Remote Sensing of Forest Resources)

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Open AccessReview

Forest Restoration Using Variable Density Thinning: Lessons from Douglas-Fir Stands in Western Oregon

by Klaus J. Puettmann, Adrian Ares, Julia I. Burton and Erich Kyle Dodson

Forests 2016, 7(12), 310; https://doi.org/10.3390/f7120310 - 7 Dec 2016

Cited by 41 | Viewed by 7695

Abstract

A large research effort was initiated in the 1990s in western United States and Canada to investigate how the development of old-growth structures can be accelerated in young even-aged stands that regenerated following clearcut harvests, while also providing income and ecosystem services. Large-scale [...] Read more.

A large research effort was initiated in the 1990s in western United States and Canada to investigate how the development of old-growth structures can be accelerated in young even-aged stands that regenerated following clearcut harvests, while also providing income and ecosystem services. Large-scale experiments were established to compare effects of thinning arrangements (e.g., spatial variability) and residual densities (including leave islands and gaps of various sizes). Treatment effects were context dependent, varying with initial conditions and spatial and temporal scales of measurement. The general trends were highly predictable, but most responses were spatially variable. Thus, accounting for initial conditions at neighborhood scales appears to be critical for efficient restoration. Different components of stand structure and composition responded uniquely to restoration thinnings. Achieving a wide range of structures and composition therefore requires the full suite of silvicultural treatments, from leave islands to variable density thinnings and creation of large gaps. Trade-offs among ecosystem services occurred as result of these contrasting responses, suggesting that foresters set priorities where and when different vegetation structures are most desirable within a stand or landscape. Finally, the results suggested that foresters should develop restoration approaches that include multiple treatments. Full article

(This article belongs to the Special Issue Stand Dynamics of Forests Managed Using Variable Retention Harvesting Systems)

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Open AccessArticle

Heterotrophic Soil Respiration Affected by Compound Fertilizer Types in Red Pine (Pinus densiflora S. et Z.) Stands of Korea

by Jaeyeob Jeong, Nanthi Bolan and Choonsig Kim

Forests 2016, 7(12), 309; https://doi.org/10.3390/f7120309 - 7 Dec 2016

Cited by 5 | Viewed by 5795

Abstract

This study was conducted to evaluate the effects of fertilizer application on heterotrophic soil respiration (Rh) in soil respiration (Rs) components in red pine stands. Two types of fertilizer (N₃P₄K₁ = 113:150:37 kg·ha⁻¹·year⁻¹; P [...] Read more.

This study was conducted to evaluate the effects of fertilizer application on heterotrophic soil respiration (Rh) in soil respiration (Rs) components in red pine stands. Two types of fertilizer (N₃P₄K₁ = 113:150:37 kg·ha⁻¹·year⁻¹; P₄K₁ = 150:37 kg·ha⁻¹·year⁻¹) were applied manually on the forest floor for two years. Rs and Rh rates were monitored from April 2011 to March 2013. Mean Rs and Rh rates were not significantly affected by fertilizer applications. However, Rh in the second year following fertilizer application fell to 27% for N₃P₄K₁ and 17% in P₄K₁ treatments, while there was an increase of 5% in the control treatments compared with the first fertilization year. The exponential relationships between Rs or Rh rates and the corresponding soil temperature were significant (Rh: R² = 0.86–0.90; p < 0.05; Rs: R² = 0.86–0.91; p < 0.05) in the fertilizer and control treatments. Q₁₀ values (Rs increase per 10 °C increase in temperature) in Rs rates were lowest for the N₃P₄K₁ treatment (3.47), followed by 3.62 for the P₄K₁ treatment and 3.60 in the control treatments, while Rh rates were similar among the treatments (3.59–3.64). The results demonstrate the importance of separating Rh rates from Rs rates following a compound fertilizer application. Full article

(This article belongs to the Special Issue Forest Soil Respiration under Climate Changing)

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Open AccessArticle

The Effect of Harvest on Forest Soil Carbon: A Meta-Analysis

by Jason James and Rob Harrison

Forests 2016, 7(12), 308; https://doi.org/10.3390/f7120308 - 7 Dec 2016

Cited by 133 | Viewed by 16282

Abstract

Forest soils represent a substantial portion of the terrestrial carbon (C) pool, and changes to soil C cycling are globally significant not only for C sequestration but also for sustaining forest productivity and ecosystem services. To quantify the effect of harvesting on soil [...] Read more.

Forest soils represent a substantial portion of the terrestrial carbon (C) pool, and changes to soil C cycling are globally significant not only for C sequestration but also for sustaining forest productivity and ecosystem services. To quantify the effect of harvesting on soil C, we used meta-analysis to examine a database of 945 responses to harvesting collected from 112 publications from around the world. Harvesting reduced soil C, on average, by 11.2% with 95% CI [14.1%, 8.5%]. There was substantial variation between responses in different soil depths, with greatest losses occurring in the O horizon (−30.2%). Much smaller but still significant losses (−3.3%) occurred in top soil C pools (0–15 cm depth). In very deep soil (60–100+ cm), a significant loss of 17.7% of soil C in was observed after harvest. However, only 21 of the 945 total responses examined this depth, indicating a substantial need for more research in this area. The response of soil C to harvesting varies substantially between soil orders, with greater losses in Spodosol and Ultisol orders and less substantial losses in Alfisols and Andisols. Soil C takes several decades to recover following harvest, with Spodosol and Ultisol C recovering only after at least 75 years. The publications in this analysis were highly skewed toward surface sampling, with a maximum sampling depth of 36 cm, on average. Sampling deep soil represents one of the best opportunities to reduce uncertainty in the understanding of the response of soil C to forest harvest. Full article

(This article belongs to the Special Issue Nutrient Cycling and Plant Nutrition in Forest Ecosystems)

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Open AccessArticle

Forest Inventory Attribute Prediction Using Lightweight Aerial Scanner Data in a Selected Type of Multilayered Deciduous Forest

by Ivan Sačkov, Giovanni Santopuoli, Tomáš Bucha, Bruno Lasserre and Marco Marchetti

Forests 2016, 7(12), 307; https://doi.org/10.3390/f7120307 - 7 Dec 2016

Cited by 21 | Viewed by 7005

Abstract

Airborne laser scanning is a promising technique for efficient and accurate, remote-based forest inventory, due to its capacity for direct measurement of the three-dimensional structure of vegetation. The main objective of this study was to test the usability and accuracy of an individual [...] Read more.

Airborne laser scanning is a promising technique for efficient and accurate, remote-based forest inventory, due to its capacity for direct measurement of the three-dimensional structure of vegetation. The main objective of this study was to test the usability and accuracy of an individual tree detection approach, using reFLex software, in the evaluation of forest variables. The accuracy assessment was conducted in a selected type of multilayered deciduous forest in southern Italy. Airborne laser scanning data were taken with a YellowScan Mapper scanner at an average height of 150 m. Point density reached 30 echoes per m², but most points belonged to the first echo. The ground reference data contained the measured positions and dimensions of 445 trees. Individual tree-detection rates were 66% for dominant, 48% for codominant, 18% for intermediate, and 5% for suppressed trees. Relative root mean square error for tree height, diameter, and volume reached 8.2%, 21.8%, and 45.7%, respectively. All remote-based tree variables were strongly correlated with the ground data (R² = 0.71–0.79). At the stand-level, the results show that differences ranged between 4% and 17% for stand height and 22% and 40% for stand diameter. The total growing stock differed by −43% from the ground reference data, and the ratios were 64% for dominant, 58% for codominant, 36% for intermediate, and 16% for suppressed trees. Full article

(This article belongs to the Special Issue LiDAR Remote Sensing of Forest Resources)

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Open AccessArticle

Male Parent Identification of Triploid Rubber Trees (Hevea brasiliensis) and the Mechanism of 2n Gametes Formation

by Peng-Qiang Yao, Guo-Hua Li, Qing-Yi Long, Li-Gang He and Xiang-Yang Kang

Forests 2016, 7(12), 301; https://doi.org/10.3390/f7120301 - 7 Dec 2016

Cited by 8 | Viewed by 4844

Abstract

Eight triploids were screened among offspring of the rubber tree clone GT1 × different clones by flow cytometry and chromosome counting. Twenty-five simple sequence repeat (SSR) markers were screened to identify the origin of 2n gametes, to determine the male parents of [...] Read more.

Eight triploids were screened among offspring of the rubber tree clone GT1 × different clones by flow cytometry and chromosome counting. Twenty-five simple sequence repeat (SSR) markers were screened to identify the origin of 2n gametes, to determine the male parents of these triploids, and to evaluate the mechanism of 2n gamete formation using band configurations and microsatellite DNA allele counting peak ratios (MAC-PR). The results showed that 2n gametes originated from the maternal rubber tree clone GT1, contributing the extra genome copy present in the triploids. It was confirmed that GT1 is able to produce a 2n megagametophyte spontaneously. Many male parents were shown to provide pollen for formation of triploid rubber trees, including clones RRIC 103, Yunyan 277-5, and three other clones. The second division restitution (SDR) was likely the main mechanism involved in formation of megagametophytes in GT1, as the rate of maternal heterozygosity restitution (HR) of all eight triploids varied from 27.78% to 75.00%, with a mean of 51.46%, and all 25 markers varied from 0% to 100%, with a mean of 51.69%. Elucidation of the origin and formation of 2n gametes will help optimize further sexual hybridization of polyploid rubber trees. Full article

(This article belongs to the Special Issue Genomics for Sustainable Forestry - Selected Papers from IUFRO Genomics and Forest Tree Genetics Conference)

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Open AccessArticle

A Basin-Scale Estimation of Carbon Stocks of a Forest Ecosystem Characterized by Spatial Distribution and Contributive Features in the Liuxihe River Basin of Pearl River Delta

by Chao Zhang, Beicheng Xia and Junyu Lin

Forests 2016, 7(12), 299; https://doi.org/10.3390/f7120299 - 6 Dec 2016

Cited by 8 | Viewed by 5535

Abstract

Forest ecosystems make a greater contribution to carbon (C) stocks than any other terrestrial ecosystem. To understand the role of regional forest ecosystems in global climate change and carbon exchange, forest C stocks and their spatial distribution within the small (2300 km² [...] Read more.

Forest ecosystems make a greater contribution to carbon (C) stocks than any other terrestrial ecosystem. To understand the role of regional forest ecosystems in global climate change and carbon exchange, forest C stocks and their spatial distribution within the small (2300 km²) Liuxihe River basin in China were analyzed to determine the different contributors to the C stocks. Forest C stocks were quantified by measuring the biomass of trees, understory vegetation, litter and roots, as well as soil organic C, using data from field samples and laboratory experiments. The results showed that forests stored 38.04 Tg·C in the entire basin, with secondary and planted forests accounting for 89.82% and 10.18%, respectively, of the stored C. Five types of forests, a subtropical evergreen broad-leaved forest, a subtropical coniferous and broad-leaved mixed forest, a subtropical coniferous forest, a timber forest, and a non-wood forest, stored 257.55 ± 15.01, 218.92 ± 9.59, 195.24 ± 18.29, 177.42 ± 17.55, and 117.86 ± 6.04 Mg·C·ha⁻¹, respectively. In the forest ecosystem C stocks of the basin, soils on average contributed about 73.78%, not including root underground biomass. The results of this study, which provide baseline forest C stock data for ecosystem services and regional C flux research, are useful to support the basin-scale forest management and land use change. Full article

(This article belongs to the Special Issue Soil Carbon Sequestration in Forests)

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Open AccessArticle

A New Skid Trail Pattern Design for Farm Tractors Using Linear Programing and Geographical Information Systems

by Selcuk Gumus and Yilmaz Turk

Forests 2016, 7(12), 306; https://doi.org/10.3390/f7120306 - 5 Dec 2016

Cited by 15 | Viewed by 6460

Abstract

Farm tractor skidding is one of the common methods of timber extraction in Turkey. However, the absence of an optimal skidding plan covering the entire production area can result in time loss and negative environmental impacts. In this study, the timber extraction by [...] Read more.

Farm tractor skidding is one of the common methods of timber extraction in Turkey. However, the absence of an optimal skidding plan covering the entire production area can result in time loss and negative environmental impacts. In this study, the timber extraction by farm tractors was analyzed, and a new skid trail pattern design was developed using Linear Programming (LP) and Geographical Information Systems (GIS). First, a sample skidding operation was evaluated with a time study, and an optimum skidding model was generated with LP. Then, the new skidding pattern was developed by an optimum skidding model and GIS analysis. At the end of the study, the developed new skid trail pattern was implemented in the study area and tested by running a time study. Using the newly developed “Direct Skid Trail Pattern (DSTP)” model, a 16.84% increase in working time performance was observed when the products were extracted by farm tractors compared to the existing practices. On the other hand, the average soil compaction value measured in the study area at depths of 0–5 cm and 5–10 cm was found to be greater in the sample area skid trails than in the control points. The average density of the skid trails was 281 m/ha, while it decreased to 187 m/ha by using the developed pattern. It was also found that 44,829 ton/ha of soil losses were prevented by using the DSTP model; therefore, environmental damages were decreased. Full article

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Open AccessArticle

Mapping Long-Term Changes in Mangrove Species Composition and Distribution in the Sundarbans

by Manoj Kumer Ghosh, Lalit Kumar and Chandan Roy

Forests 2016, 7(12), 305; https://doi.org/10.3390/f7120305 - 3 Dec 2016

Cited by 74 | Viewed by 12297

Abstract

The Sundarbans mangrove forest is an important resource for the people of the Ganges Delta. It plays an important role in the local as well as global ecosystem by absorbing carbon dioxide and other pollutants from air and water, offering protection to millions [...] Read more.

The Sundarbans mangrove forest is an important resource for the people of the Ganges Delta. It plays an important role in the local as well as global ecosystem by absorbing carbon dioxide and other pollutants from air and water, offering protection to millions of people in the Ganges Delta against cyclone and water surges, stabilizing the shore line, trapping sediment and nutrients, purifying water, and providing services for human beings, such as fuel wood, medicine, food, and construction materials. However, this mangrove ecosystem is under threat, mainly due to climate change and anthropogenic factors. Anthropogenic and climate change-induced degradation, such as over-exploitation of timber and pollution, sea level rise, coastal erosion, increasing salinity, effects of increasing number of cyclones and higher levels of storm surges function as recurrent threats to mangroves in the Sundarbans. In this situation, regular and detailed information on mangrove species composition, their spatial distribution and the changes taking place over time is very important for a thorough understanding of mangrove biodiversity, and this information can also lead to the adoption of management practices designed for the maximum sustainable yield of the Sundarbans forest resources. We employed a maximum likelihood classifier technique to classify images recorded by the Landsat satellite series and used post classification comparison techniques to detect changes at the species level. The image classification resulted in overall accuracies of 72%, 83%, 79% and 89% for the images of 1977, 1989, 2000 and 2015, respectively. We identified five major mangrove species and detected changes over the 38-year (1977–2015) study period. During this period, both Heritiera fomes and Excoecaria agallocha decreased by 9.9%, while Ceriops decandra, Sonneratia apelatala, and Xylocarpus mekongensis increased by 12.9%, 380.4% and 57.3%, respectively. Full article

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Open AccessArticle

Assessment of Geographic Information System (GIS) Skills Employed by Graduates from Three Forestry Programs in the United States

by Krista Merry, Pete Bettinger, Donald L. Grebner, Kevin Boston and Jacek Siry

Forests 2016, 7(12), 304; https://doi.org/10.3390/f7120304 - 1 Dec 2016

Cited by 7 | Viewed by 5697

Abstract

This research evaluates the current use of geographic information systems (GIS) by forestry program graduates employed in the United States who graduated from university in the past five years. The purpose was to understand what geospatial processes and databases are typically used by [...] Read more.

This research evaluates the current use of geographic information systems (GIS) by forestry program graduates employed in the United States who graduated from university in the past five years. The purpose was to understand what geospatial processes and databases are typically used by field foresters. A survey was designed and sent to recent forestry graduates from Mississippi State University, Oregon State University, and the University of Georgia, with 30% of those surveyed choosing to participate. The majority of forestry graduates surveyed use GIS at least once a week, and the most frequently employed tasks included editing tabular data, adjusting polygon boundaries, buffering and splitting polygons, and querying for spatial and tabular information. Very few overlay or advance spatial analysis tools were noted as used in regular work efforts. Most respondents use digital aerial photographs as reference, along with satellite images. LiDAR is increasingly being used by these foresters, but to a lesser extent. ArcMap and Google Earth were noted as the most commonly used software packages. Most foresters rely on an organization’s technical support staff for assistance. The study results can be used as a guide for academic programs in their efforts to provide timely and effective knowledge on geospatial topics to forestry undergraduate students. Full article

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Open AccessArticle

Evaluation of Whole Tree Growth Increment Derived from Tree-Ring Series for Use in Assessments of Changes in Forest Productivity across Various Spatial Scales

by Juha M. Metsaranta and Jagtar S. Bhatti

Forests 2016, 7(12), 303; https://doi.org/10.3390/f7120303 - 1 Dec 2016

Cited by 14 | Viewed by 5277

Abstract

The inherent predictability of inter-annual variation in forest productivity remains unknown. Available field-based data sources for understanding this variability differ in their spatial resolution, temporal resolution, and typical units of measure. Nearly all other tree and forest characteristics are in practice derived from [...] Read more.

The inherent predictability of inter-annual variation in forest productivity remains unknown. Available field-based data sources for understanding this variability differ in their spatial resolution, temporal resolution, and typical units of measure. Nearly all other tree and forest characteristics are in practice derived from measurements of diameter at breast height (DBH). Therefore, diameter increment reconstructed annually from tree-ring data can be used to estimate annual growth increments of wood volume, but the accuracy and precision of these estimates requires assessment. Annual growth estimates for n = 170 trees sampled for whole stem analysis from five tree species (jack pine, lodgepole pine, black spruce, white spruce, and trembling aspen) in Western Canada were compared against increments derived from breast height measurements only. Inter-annual variability of breast height and whole tree growth increments was highly correlated for most trees. Relative errors varied by species, diameter class, and the equation used to estimate volume (regional vs. national). A simple example of the possible effect of this error when propagated to the stand level is provided. Full article

(This article belongs to the Special Issue Nutrient Cycling and Plant Nutrition in Forest Ecosystems)

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Open AccessArticle

Estimation of Nutrient Exports Resulting from Thinning and Intensive Biomass Extraction in Medium-Aged Spruce and Pine Stands in Saxony, Northeast Germany

by Christine Knust, Karoline Schua and Karl-Heinz Feger

Forests 2016, 7(12), 302; https://doi.org/10.3390/f7120302 - 30 Nov 2016

Cited by 16 | Viewed by 5180

Abstract

A growing interest in using forest biomass for bioenergy generation may stimulate intensive harvesting scenarios in Germany. We calculated and compared nutrient exports of conventional stem only (SO), whole tree without needles (WT excl. needles), and whole tree (WT) harvesting in two medium [...] Read more.

A growing interest in using forest biomass for bioenergy generation may stimulate intensive harvesting scenarios in Germany. We calculated and compared nutrient exports of conventional stem only (SO), whole tree without needles (WT excl. needles), and whole tree (WT) harvesting in two medium aged Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.) stands differing in productivity, and related them to soil nutrient pools and fluxes at the study sites. We established allometric biomass functions for each aboveground tree compartment and analyzed their nutrient contents. We analyzed soil nutrient stocks, estimated weathering rates, and obtained deposition and seepage data from nearby Level II stations. WT (excl. needles) and WT treatments cause nutrient losses 1.5 to 3.6 times higher than SO, while the biomass gain is only 1.18 to 1.25 in case of WT (excl. needles) and 1.28 to 1.30 in case of WT in the pine and spruce stand, respectively. Within the investigated 25-year period, WT harvesting would cause exports of N, K⁺, Ca²⁺, and Mg²⁺ of 6.6, 8.8, 5.4, and 0.8 kg·ha⁻¹ in the pine stand and 13.9, 7.0, 10.6, and 1.8 kg·ha⁻¹ in the spruce stand annually. The relative impact of WT and WT (excl. needles) on the nutrient balance is similar in the pine and spruce stands, despite differences in stand productivities, and thus the absolute amount of nutrients removed. In addition to the impact of intensive harvesting, both sites are characterized by high seepage losses of base cations, further impairing the nutrient budget. While intensive biomass extraction causes detrimental effects on many key soil ecological properties, our calculations may serve to implement measures to improve the nutrient balance in forested ecosystems. Full article

(This article belongs to the Special Issue Nutrient Cycling and Plant Nutrition in Forest Ecosystems)

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Open AccessArticle

Transforming Justice in REDD+ through a Politics of Difference Approach

by Kimberly R. Marion Suiseeya

Forests 2016, 7(12), 300; https://doi.org/10.3390/f7120300 - 30 Nov 2016

Cited by 15 | Viewed by 5781

Abstract

Since Reduced Emissions from Deforestation and Degradation “Plus” (REDD+) starting gaining traction in the UN climate negotiations in 2007, its architects and scholars have grappled with its community-level justice implications. On the one hand, supporters argue that REDD+ will help the environment and [...] Read more.

Since Reduced Emissions from Deforestation and Degradation “Plus” (REDD+) starting gaining traction in the UN climate negotiations in 2007, its architects and scholars have grappled with its community-level justice implications. On the one hand, supporters argue that REDD+ will help the environment and forest-dependent communities by generating payments for forest carbon services from industrialized countries seeking lower cost emissions reductions. Critics, by contrast, increasingly argue that REDD+ is a new form of colonization through capitalism, producing injustice by stripping forest communities of their rights, denying them capabilities for wellbeing, and rendering forest peoples voiceless in forest governance. This paper argues that current REDD+ debates are too focused on relatively simple visions of either distributive or procedural justice, and pay too little attention to the core recognitional justice concerns of REDD+ critics, namely questions of what values, worldviews, rights, and identities are privileged or displaced in the emergence, design, and implementation of REDD+ and with what effects. This paper examines the tensions that emerge when designing institutions to promote multi-scalar, multivalent justice in REDD+ to ask: what are the justice demands that REDD+ architects face when designing REDD+ institutions? Complexifying the concepts of justice as deployed in the debates on REDD+ can illuminate the possibilities for a diversity of alternative perspectives to generate new institutional design ideas for REDD+. Full article

(This article belongs to the Special Issue REDD+ Crossroads Post Paris: Politics, Lessons and Interplays)

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Open AccessArticle

Drought Stress Distribution Responses of Continental Beech Forests at their Xeric Edge in Central Europe

by Éva Salamon-Albert, Péter Lőrincz, Gábor Pauler, Dénes Bartha and Ferenc Horváth

Forests 2016, 7(12), 298; https://doi.org/10.3390/f7120298 - 29 Nov 2016

Cited by 12 | Viewed by 5794

Abstract

In order to develop adequate adaptation measures for environmental vulnerability, we need detailed knowledge on the climatic performance of forest ecosystems. In this study, we aim to explore climate function variability of lowland beech forest distribution at a landscape scale. We also construct [...] Read more.

In order to develop adequate adaptation measures for environmental vulnerability, we need detailed knowledge on the climatic performance of forest ecosystems. In this study, we aim to explore climate function variability of lowland beech forest distribution at a landscape scale. We also construct the response profiles of these forests near their xeric limit under wet continental climatic conditions. We studied distribution responses using presence-absence forest records and 18 bioclimatic variables. We performed exploratory factor analysis and frequency estimation to evaluate climate function distribution responses. We found that temperature adjusted precipitation measures during summer were the most important, followed by winter rainfall indices. The relative Drought Response Range (rDRR) in the response profile presented the climate limitation function of the distribution. According to our results, higher level of climate function variability is associated with lower level of rDRR, presenting an ecological trade-off. Our results suggest that distribution functions of the rDRR, especially the Ombrothermic index, can be used as landscape indicators of drought stress. Consequently, rDRR could be a useful measure to assess regional climatic vulnerability of forest occurrence and distribution patterns. Full article

(This article belongs to the Special Issue Forest Growth Response to Environmental Stress)

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Open AccessArticle

The Biodiversity Benefits and Opportunity Costs of Plantation Forest Management: A Modelling Case Study of Pinus radiata in New Zealand

by Nhung Nghiem and Hop Tran

Forests 2016, 7(12), 297; https://doi.org/10.3390/f7120297 - 28 Nov 2016

Cited by 6 | Viewed by 6459

Abstract

This study modelled the potential biodiversity benefits and the opportunity costs of a patch-clear-cutting strategy over a clear-cutting strategy for Pinus radiata in New Zealand. Patch-clear cutting is a special case of clear cutting involving the removal of all the trees from strips [...] Read more.

This study modelled the potential biodiversity benefits and the opportunity costs of a patch-clear-cutting strategy over a clear-cutting strategy for Pinus radiata in New Zealand. Patch-clear cutting is a special case of clear cutting involving the removal of all the trees from strips or patches within a stand, leaving the remainder uncut or clear cutting a series of strips or patches. A forest-level optimisation model was extended to include uncertainty in timber growth, plant diversity, and cutting costs. Using a species-area relationship and economies of cutting scale, the net present value and optimal rotation age under alternative management strategies were calculated. Results suggested that the optimal rotation ages were similar (24 and 25 years) for the two cutting strategies. Patch-clear cutting provided higher biodiversity benefits (i.e., 59 vs. 11 understorey plant species) with an opportunity cost of 27 NZD (18 USD) per extra plant species or 1250 NZD (820 USD) ha⁻¹. However, the true benefits of patch-clear cutting would be even greater if other benefits of stand retention are included. Our research can potentially inform local decision making and inform international systems of payment for environmental services, such as the REDD+ (Reducing Emissions from Deforestation and Forest Degradation) program, to conserve biodiversity in developing countries with plantation forests. Full article

(This article belongs to the Special Issue Intensity of Forest Management—Selected Papers from FowiTa German Forest Sciences Conference (Sessions 10–14))

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2549 KiB

Open AccessCommunication

Increasing Water Use Efficiency Comes at a Cost for Norway Spruce

by Tanja G M Sanders, Ingo Heinrich, Björn Günther and Wolfgang Beck

Forests 2016, 7(12), 296; https://doi.org/10.3390/f7120296 - 28 Nov 2016

Cited by 8 | Viewed by 5682

Abstract

Intrinsic water use efficiency (WUE_i) in trees is an indication of the ratio of carbon assimilation to the rate of transpiration. It is generally assumed that it is a response to water availability. In agricultural research, the question of drought tolerance [...] Read more.

Intrinsic water use efficiency (WUE_i) in trees is an indication of the ratio of carbon assimilation to the rate of transpiration. It is generally assumed that it is a response to water availability. In agricultural research, the question of drought tolerance by increased WUE_i has been well studied. In general, the increase is a trade-off for productivity and is therefore not desired. For forest trees, this question is less clearly understood. Using stable carbon isotopes derived from tree rings combined with productivity as the product of the annual growth increment and annual density measurements, we compared the change in WUE_i over a 15 year period. While WUE_i increased over this period, the productivity decreased, causing an opposing trend. The gradient of the correlation between WUE_i and productivity varies between provenances and sites. Counterintuitively, the populations at the drier site showed low WUE_i values at the beginning of the investigation. Slopes vary with the provenance from Poland showing the least decline in productivity. In general, we found that a decline in productivity aligned with an increase in WUE_i. Full article

(This article belongs to the Special Issue Climate Change Impacts on the Dynamics of Forest Ecosystems)

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Open AccessArticle

Radial Growth Response of Larix gmelinii to Climate along a Latitudinal Gradient in the Greater Khingan Mountains, Northeastern China

by Yangao Jiang, Junhui Zhang, Shijie Han, Zhenju Chen, Heikki Setälä, Jinghua Yu, Xingbo Zheng, Yingtao Guo and Yue Gu

Forests 2016, 7(12), 295; https://doi.org/10.3390/f7120295 - 28 Nov 2016

Cited by 29 | Viewed by 5819

Abstract

To explore how climatic factors influence tree growth within the context of global climate changes, we used a dendroclimatological analysis to understand the response of Larix gmelinii to climatic variations along a broad latitudinal gradient from 47.27° to 52.66° N in the Greater [...] Read more.

To explore how climatic factors influence tree growth within the context of global climate changes, we used a dendroclimatological analysis to understand the response of Larix gmelinii to climatic variations along a broad latitudinal gradient from 47.27° to 52.66° N in the Greater Khingan Mountains of Northeastern China. The growth-limiting climate factors and a detailed association between radial growth and climate were identified along the gradient using redundancy analysis (RDA) and standard correlation function analysis over the period 1960–2013. The results showed that temperatures during current June to July represented the most important factor affecting tree radial growth in the study area. Across all studied latitudes, Larix gmelinii growth might be decreasing in radial growth due to higher monthly maximum temperature (Tmax) and monthly mean temperatures (Tm) in the current June, especially for the stands at low and middle latitudes. With continued warming, Larix gmelinii radial growth at high latitudes (e.g., Mangui (MG) and Mohe (MH)) might be reduced by warmer temperatures in July. In addition, Larix gmelinii might be decreasing in radial growth from decreasing precipitation. Our results show that there is a decreasing trend in Larix gmelinii radial growth under the observed general increase of temperatures in the Greater Khingan Mountains in recent years. Full article

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Open AccessArticle

Assessment of Aboveground Woody Biomass Dynamics Using Terrestrial Laser Scanner and L-Band ALOS PALSAR Data in South African Savanna

by Victor Onyango Odipo, Alecia Nickless, Christian Berger, Jussi Baade, Mikhail Urbazaev, Christian Walther and Christiane Schmullius

Forests 2016, 7(12), 294; https://doi.org/10.3390/f7120294 - 25 Nov 2016

Cited by 24 | Viewed by 10959

Abstract

The use of optical remote sensing data for savanna vegetation structure mapping is hindered by sparse and heterogeneous distribution of vegetation canopy, leading to near-similar spectral signatures among lifeforms. An additional challenge to optical sensors is the high cloud cover and unpredictable weather [...] Read more.

The use of optical remote sensing data for savanna vegetation structure mapping is hindered by sparse and heterogeneous distribution of vegetation canopy, leading to near-similar spectral signatures among lifeforms. An additional challenge to optical sensors is the high cloud cover and unpredictable weather conditions. Longwave microwave data, with its low sensitivity to clouds addresses some of these problems, but many space borne studies are still limited by low quality structural reference data. Terrestrial laser scanning (TLS) derived canopy cover and height metrics can improve aboveground biomass (AGB) prediction at both plot and landscape level. To date, few studies have explored the strength of TLS for vegetation structural mapping, and particularly few focusing on savannas. In this study, we evaluate the potential of high resolution TLS-derived canopy cover and height metrics to estimate plot-level aboveground biomass, and to extrapolate to a landscape-wide biomass estimation using multi-temporal L-band Synthetic Aperture Radar (SAR) within a 9 km² area savanna in Kruger National Park (KNP). We inventoried 42 field plots in the wet season and computed AGB for each plot using site-specific allometry. Canopy cover, canopy height, and their product were regressed with plot-level AGB over the TLS-footprint, while SAR backscatter was used to model dry season biomass for the years 2007, 2008, 2009, and 2010 for the study area. The results from model validation showed a significant linear relationship between TLS-derived predictors with field biomass, p < 0.05 and adjusted R² ranging between 0.56 for SAR to 0.93 for the TLS-derived canopy cover and height. Log-transformed AGB yielded lower errors with TLS metrics compared with non-transformed AGB. An assessment of the backscatter based on root mean square error (RMSE) showed better AGB prediction with cross-polarized (RMSE = 6.6 t/ha) as opposed to co-polarized data (RMSE = 6.7 t/ha), attributed to volume scattering of woody vegetation along river valleys and streams. The AGB change analysis showed 32 ha (3.5%) of the 900 ha experienced AGB loses above an average of 5 t/ha per annum, which can mainly be attributed to the falling of trees by mega herbivores such as elephants. The study concludes that SAR data, especially L-band SAR, can be used in the detection of small changes in savanna vegetation over time. Full article

(This article belongs to the Special Issue Forest Ground Observations through Terrestrial Point Clouds)

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Open AccessArticle

A Model to Estimate Willingness to Pay for Harvest Permits for Wild Edible Mushrooms: Application to Andalusian Forests

by Pablo De Frutos, Fernando Martinez-Peña, Jorge Aldea and Pablo Campos

Forests 2016, 7(12), 292; https://doi.org/10.3390/f7120292 - 25 Nov 2016

Cited by 8 | Viewed by 5265

Abstract

Public demand for harvesting wild edible mushrooms has risen in recent decades and currently affects many forested areas around the world. The idea of introducing permits for users has been conceived as a tool for ecosystem management. The problem is that policy-makers lack [...] Read more.

Public demand for harvesting wild edible mushrooms has risen in recent decades and currently affects many forested areas around the world. The idea of introducing permits for users has been conceived as a tool for ecosystem management. The problem is that policy-makers lack the necessary means to help guide them when establishing prices for such harvesting permits. Valuing the recreational benefits which mushroom harvesters derive from harvesting wild edible mushrooms may provide certain guidelines as to how much people would be willing to pay and may also justify future payments levied on harvesters. The aim of the present article is to estimate a model for determining citizens’ willingness to pay for a harvesting permit in a forest in Andalusia (Spain) using contingent valuation methods. Results show that mean willingness to pay is 22.61 Euros (USD28.18) per harvester and season. This amount depends on several socioeconomic factors and preferences related to harvesters’ experiences. Full article

(This article belongs to the Special Issue Management Strategies for Forest Ecosystem Services)

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Open AccessArticle

The Effects of Fertilization on the Growth and Physiological Characteristics of Ginkgo biloba L.

by Jing Guo, Yaqiong Wu, Bo Wang, Yan Lu, Fuliang Cao and Guibin Wang

Forests 2016, 7(12), 293; https://doi.org/10.3390/f7120293 - 24 Nov 2016

Cited by 46 | Viewed by 8316

Abstract

Ginkgo biloba L. is one of the most extensively planted and productive commercial species in temperate areas around the world, but slow-growth is the most limiting factor for its utilization. Fertilization is one of the key technologies for high quality and high forest [...] Read more.

Ginkgo biloba L. is one of the most extensively planted and productive commercial species in temperate areas around the world, but slow-growth is the most limiting factor for its utilization. Fertilization is one of the key technologies for high quality and high forest yield. To better understand the impacts of fertilization on Ginkgo productivity, the effects of fertilization treatments (single fertilizer and combined fertilizer) on growth, nutrient content in Ginkgo leaves, and photosynthesis characteristics were studied in a 10-year-old Ginkgo plantation over two years. The single factor experiments suggested that DBH (diameter at breast height), H (height), NSL (length of new shoots), and V (trunk volume) showed significant differences between the different levels of single nitrogen (N) or phosphate (P) fertilizer application. Orthogonal test results showed that the nine treatments all promoted the growth of Ginkgo, and the formula (N: 400 g·tree⁻¹, P: 200 g·tree⁻¹, potassium (K): 90 g·tree⁻¹) was the most effective. G_s (stomatal conductance) and P_n (net photosynthesis rate) showed significant differences between the different amounts of single N or P fertilizer application, while single K fertilizer only affected P_n. Combined N, P, and K fertilizer had significant promoting effects on C_i (intercellular CO₂ concentration), G_s and P_n. N and P contents in Ginkgo leaves showed significant differences between the different amounts of a single N fertilizer application. A single P fertilizer only improved foliar P contents in Ginkgo leaves. A single K fertilizer application improved N and K content in Ginkgo leaves. The effects of different N, P, and K fertilizer treatments on the nutrient content of Ginkgo leaves were different. Full article

(This article belongs to the Special Issue Nutrient Cycling and Plant Nutrition in Forest Ecosystems)

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Open AccessEditorial

The Biodiversity of Urban and Peri-Urban Forests and the Diverse Ecosystem Services They Provide as Socio-Ecological Systems

by Stephen J. Livesley, Francisco J. Escobedo and Justin Morgenroth

Forests 2016, 7(12), 291; https://doi.org/10.3390/f7120291 - 24 Nov 2016

Cited by 36 | Viewed by 9286

Abstract

Urban and peri-urban forests provide a variety of ecosystem service benefits for urban society. Recognising and understanding the many human–tree interactions that urban forests provide may be more complex but probably just as important to our urbanised society. This paper introduces four themes [...] Read more.

Urban and peri-urban forests provide a variety of ecosystem service benefits for urban society. Recognising and understanding the many human–tree interactions that urban forests provide may be more complex but probably just as important to our urbanised society. This paper introduces four themes that link the studies from across the globe presented in this Special Issue: (1) human–tree interactions; (2) urban tree inequity; (3) carbon sequestration in our own neighbourhoods; and (4) biodiversity of urban forests themselves and the fauna they support. Urban forests can help tackle many of the “wicked problems” that confront our towns and cities and the people that live in them. For urban forests to be accepted as an effective element of any urban adaptation strategy, we need to improve the communication of these ecosystem services and disservices and provide evidence of the benefits provided to urban society and individuals, as well as the biodiversity with which we share our town and cities. Full article

(This article belongs to the Special Issue Urban and Periurban Forest Diversity and Ecosystem Services)

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