Forests

10700 KiB

Open AccessArticle

Drivers of CO₂ Emission Rates from Dead Wood Logs of 13 Tree Species in the Initial Decomposition Phase

by Tiemo Kahl, Kristin Baber, Peter Otto, Christian Wirth and Jürgen Bauhus

Forests 2015, 6(7), 2484-2504; https://doi.org/10.3390/f6072484 - 20 Jul 2015

Cited by 42 | Viewed by 9389

Large dead wood is an important structural component of forest ecosystems and a main component of forest carbon cycles. CO₂ emissions from dead wood can be used as a proxy for actual decomposition rates. The main drivers of CO₂ emission rates [...] Read more.

Large dead wood is an important structural component of forest ecosystems and a main component of forest carbon cycles. CO₂ emissions from dead wood can be used as a proxy for actual decomposition rates. The main drivers of CO₂ emission rates for dead wood of temperate European tree species are largely unknown. We applied a novel, closed chamber measurement technique to 360 dead wood logs of 13 important tree species in three regions in Germany. We found that tree species identity was with 71% independent contribution to the model (R² = 0.62) the most important driver of volume-based CO₂ emission rates, with angiosperms having on average higher rates than conifers. Wood temperature and fungal species richness had a positive effect on CO₂ emission rates, whereas wood density had a negative effect. This is the first time that positive fungal species richness—wood decomposition relationship in temperate forests was shown. Certain fungal species were associated with high or low CO₂ emission rates. In addition, as indicated by separate models for each tree species, forest management intensity, study region, and the water content as well as C and N concentration of dead wood influenced CO₂ emission rates. Full article

(This article belongs to the Special Issue Greenhouse Gas Fluxes from Below and Aboveground Forest Deadwood)

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5207 KiB

Open AccessArticle

Molecular Identification of Phytoplasmas Infecting Diseased Pine Trees in the UNESCO-Protected Curonian Spit of Lithuania

by Deividas Valiunas, Rasa Jomantiene, Algirdas Ivanauskas, Indre Urbonaite, Donatas Sneideris and Robert E. Davis

Forests 2015, 6(7), 2469-2483; https://doi.org/10.3390/f6072469 - 17 Jul 2015

Cited by 21 | Viewed by 7043

Abstract

Although mainly known as pathogens that affect angiosperms, phytoplasmas have recently been detected in diseased coniferous plants. In 2008–2014, we observed, in the Curonian Spit of Western Lithuania and in forests of Southern Lithuania (Varena district), diseased trees of Scots pine (Pinus [...] Read more.

Although mainly known as pathogens that affect angiosperms, phytoplasmas have recently been detected in diseased coniferous plants. In 2008–2014, we observed, in the Curonian Spit of Western Lithuania and in forests of Southern Lithuania (Varena district), diseased trees of Scots pine (Pinus sylvestris) and mountain pine (Pinus mugo) with unusual symptoms similar to those caused by phytoplasmas. Diseased trees exhibited excessive branching, dwarfed reddish or yellow needles, dried shoots and ball-like structures. restriction fragment length polymorphism (RFLP) and nucleotide sequence analysis of 16S rRNA gene fragments revealed that individual trees were infected by Candidatus (Ca.) Phytoplasma pini-related strains (members of phytoplasma subgroup 16SrXXI-A) or by Ca. Phytoplasma asteris-related strains (subgroup 16SrI-A). Of the nearly 300 trees that were sampled, 80% were infected by phytoplasma. Ninety-eight percent of the positive samples were identified as Ca. Phytoplasma pini-related strains. Strains belonging to subgroup 16SrI-A were identified from only few trees. Use of an additional molecular marker, secA, supported the findings. This study provides evidence of large-scale infection of Pinus by Ca. Phytoplasma pini in Lithuania, and it reveals that this phytoplasma is more widespread geographically than previously appreciated. This is also the first report of phytoplasma subgroup 16SrI-A in pine trees. Full article

(This article belongs to the Special Issue Joint IUFRO 7.02.02 “Foliage, shoot and stem diseases of forest trees” and 7.03.04 “Diseases and insects in forest nurseries” Working Parties Meeting)

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3745 KiB

Open AccessArticle

Occurrence of Density-Dependent Height Repression within Jack Pine and Black Spruce Populations

by Peter F. Newton

Forests 2015, 6(7), 2450-2468; https://doi.org/10.3390/f6072450 - 16 Jul 2015

Cited by 5 | Viewed by 4467

Abstract

The objective of this study was to investigate the occurrence of density-dependent height relationships in jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana (Mill.) B.S.P.) populations. After assessing and ruling out the presence of consequential spatial correlation effects, the [...] Read more.

The objective of this study was to investigate the occurrence of density-dependent height relationships in jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana (Mill.) B.S.P.) populations. After assessing and ruling out the presence of consequential spatial correlation effects, the analysis consisted of analyzing the relationship between mean dominant height and initial planting density within 28 Nelder plots located in the central portion of the Canadian Boreal Forest Region. Employing remeasurement data obtained at periodic intervals (16, 20 and 40–41 years post-establishment) across a stand density gradient ranging from a minimum of 1425 stems/ha to a maximum of 28,621 stems/ha, graphical and simple linear regression analyses were used to quantify the stand height–density relationship by species, plot and measurement year. The results indicated the presence of density-dependent effects on height development for both species: 65% of the 83 jack pine relationships and 89% of the 27 black spruce relationships had significant (p ≤ 0.05) and negative slope values. In regards to jack pine for which the data permitted, the occurrence and magnitude of the observed height repression effect increased over time. The asymptotic height repression effect for jack pine was 24% greater than that for black spruce. The results are discussed within the context of the applicability of the density-independent height growth assumption and potential implications for site quality estimation and thinning response modeling. Full article

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14402 KiB

Open AccessArticle

Comparing the Costs and Revenues of Transformation to Continuous Cover Forestry for Sitka Spruce in Great Britain

by Owen Davies and Gary Kerr

Forests 2015, 6(7), 2424-2449; https://doi.org/10.3390/f6072424 - 15 Jul 2015

Cited by 19 | Viewed by 7824

Abstract

Recently continuous cover forestry (CCF) has become an accepted approach to forest management in Britain, but uncertainty about its economic consequences may be a barrier to its wider use. A study was carried out to examine the costs and revenues of transforming a [...] Read more.

Recently continuous cover forestry (CCF) has become an accepted approach to forest management in Britain, but uncertainty about its economic consequences may be a barrier to its wider use. A study was carried out to examine the costs and revenues of transforming a stand of Sitka spruce (Picea sitchensis (Bong.) Carr.) to CCF. The main conclusion is that transformation to CCF need not be more costly than clearfelling and replanting if natural regeneration is successful and the aim is to produce a simple canopy structure. The long-term value of transformation to a more complex canopy structure, with three or more strata, is lower and the extra costs need to be justified in terms of management objectives. The main output from the study is an analysis spreadsheet that empowers practitioners and policy makers to investigate the effects of costs, revenues and discount rates on estimates of net present value over 20 years, 100 years and in perpetuity, to suit local conditions. This paper summarises the method and results of the study in a British context, sets these in a wider international context, and considers the merits, applications and possible further developments of the approach. Full article

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397 KiB

Open AccessArticle

Adapting Free, Prior, and Informed Consent (FPIC) to Local Contexts in REDD+: Lessons from Three Experiments in Vietnam

by Thuy Thu Pham, Jean-Christophe Castella, Guillaume Lestrelin, Ole Mertz, Dung Ngoc Le, Moira Moeliono, Tan Quang Nguyen, Hien Thi Vu and Tien Dinh Nguyen

Forests 2015, 6(7), 2405-2423; https://doi.org/10.3390/f6072405 - 15 Jul 2015

Cited by 21 | Viewed by 7862

Abstract

Free, prior, and informed consent (FPIC) is a means of ensuring that people’s rights are respected when reducing emissions from deforestation and forest degradation, and enhancing forest carbon stocks (REDD+) projects are established in developing countries. This paper examines how FPIC has been [...] Read more.

Free, prior, and informed consent (FPIC) is a means of ensuring that people’s rights are respected when reducing emissions from deforestation and forest degradation, and enhancing forest carbon stocks (REDD+) projects are established in developing countries. This paper examines how FPIC has been applied in three projects in Vietnam and highlights two key lessons learnt. First, as human rights and democracy are seen as politically sensitive issues in Vietnam, FPIC is likely to be more accepted by the government if it is built upon the national legal framework on citizen rights. Applying FPIC in this context can ensure that both government and citizen’s interests are achieved within the permitted political space. Second, FPIC activities should be seen as a learning process and designed based on local needs and preferences, with accountability of facilitators, two-way and multiple communication strategies, flexibility, and collective action in mind. Full article

301 KiB

Open AccessArticle

Low Nitrogen Retention in Soil and Litter under Conditions without Plants in a Subtropical Pine Plantation

by Yanmei Xiong, Xingliang Xu, Hui Zeng, Huimin Wang, Fusheng Chen and Dali Guo

Forests 2015, 6(7), 2387-2404; https://doi.org/10.3390/f6072387 - 15 Jul 2015

Cited by 4 | Viewed by 4797

Abstract

Soil acts as a major sink for added nitrogen (N) in forests, but it remains unclear about the capacity of soil to immobilize N under conditions without plant roots and whether added N interacts with ecosystem N to affect N retention. We added [...] Read more.

Soil acts as a major sink for added nitrogen (N) in forests, but it remains unclear about the capacity of soil to immobilize N under conditions without plant roots and whether added N interacts with ecosystem N to affect N retention. We added ¹⁵NH₄¹⁵NO₃ to in situ soil columns (with leaching) and leaf litter (without leaching) of two tree species in a subtropical Pinus elliottii plantation. Soil and litter were collected three or eight months after N addition to measure concentrations of indigenous and exogenous N. About 70% of exogenous N was retained in soil three months after N addition, of which 65.9% were in inorganic forms. Eight months after N addition, 16.0% of exogenous N was retained in soil and 9.8%–13.6% was immobilized in litter. N addition increased the mineral release and nitrification of soil indigenous N. Loss of litter indigenous N was also increased by N addition. Our results suggest that N deposition on lands with low root activities or low soil carbon (C) contents may lead to increased N output due to low N immobilization. Moreover, the effects of added N on ecosystem indigenous N may decrease the capacity of soil and litter in N retention. Full article

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418 KiB

Open AccessArticle

Assessing the Effect of Leaf Litter Diversity on the Decomposition and Associated Diversity of Fungal Assemblages

by Jing Gao, Fengfeng Kang, Tianyu Li, Xiaoshuai Song, Weihong Zhao, Xiaowen Yu and Hairong Han

Forests 2015, 6(7), 2371-2386; https://doi.org/10.3390/f6072371 - 14 Jul 2015

Cited by 14 | Viewed by 5183

Abstract

Although the effect of litter mixture on decomposition has been well documented, few studies have examined the relationships between richness and relative abundance of leaf species in litter mixture and changes in universal fungal communities during the decomposition process in temperate forests. In [...] Read more.

Although the effect of litter mixture on decomposition has been well documented, few studies have examined the relationships between richness and relative abundance of leaf species in litter mixture and changes in universal fungal communities during the decomposition process in temperate forests. In this study, we used the litterbag method and included three leaf litter species, i.e., aspen (Populus davidiana Dode), birch (Betula platyphylla Sukaczev) and oak (Quercus mongolica Fischer ex Ledebour), to investigate the mass loss rate and diversity of universal fungal communities in each litter treatment, which were sampled in situ after 180, 240, 300 and 360 days of decomposition (between 2012 and 2013) in broadleaved mixed forests in Chinese temperate forests. Eight mixture proportions were examined: pure aspen litter (10A), pure birch litter (10B), pure oak litter (10O), 50% aspen litter mixed with 50% birch litter (5A:5B), 50% aspen litter mixed with 50% oak (5A:5O), 50% birch litter mixed with 50% oak litter (5B:5O), 10% birch litter mixed with 80% aspen litter and 10% oak litter (1B:8A:1O), 30% birch litter mixed with 40% aspen litter and 30% oak litter (3B:4A:3O). Over 360 days of decomposition, approximately 46.6%, 43.6%, 28.0%, 54.4%, 40.2%, 39.5%, 54.5% and 49.46% of litter mass was lost from 10A, 10B, 10O, 5A:5B, 5A:5O, 5B:5O, 1B:8A:1O and 3B:4A:3O, respectively. In addition, the number of fungal denaturing gradient gel electrophoresis (DGGE) bands showed a positive correlation with mass loss rate, indicating a positive feedback between leaf litter decomposition and universal fungal communities in the leaf litter. The results revealed that the 5A:5B, 1B:8A:1O and 3B:4A:3O litter mixtures had a synergistic effect on the litter mixture, while the 5A:5O and 5B:5O litter mixtures had a nearly neutral effect on the litter mixture. Thus, leaf litter species composition and relative abundance seem to be more important than leaf litter richness in driving the direction and magnitude of litter mixture decomposition. Full article

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7002 KiB

Open AccessArticle

Ecological Conservation, Ecotourism, and Sustainable Management: The Case of Penang National Park

by Sara Kaffashi, Alias Radam, Mad Nasir Shamsudin, Mohd Rusli Yacob and Nor Hanim Nordin

Forests 2015, 6(7), 2345-2370; https://doi.org/10.3390/f6072345 - 7 Jul 2015

Cited by 46 | Viewed by 11856

Abstract

Penang National Park (PNP), as Malaysia’s smallest national park, is one of the few naturally forested areas left on Penang Island, in Peninsular Malaysia. The main objective was to analyse users’ preferences and willingness to pay to enhance improved management of PNP for [...] Read more.

Penang National Park (PNP), as Malaysia’s smallest national park, is one of the few naturally forested areas left on Penang Island, in Peninsular Malaysia. The main objective was to analyse users’ preferences and willingness to pay to enhance improved management of PNP for the dual aim of conservation and recreation. Structural equation modelling (SEM) was used to analyse the formation of attitudes towards different aspects of PNP. Results showed that implementing enforcements with rules and regulations and imposing permits and charges on certain activities were the most influential variables of PNPs’ perceptions. The results of a random parameter logit model (RPL) demonstrated that visitors placed the highest value on having adequate information about PNP, and the second-highest value on improvements in the park’s ecological management. The welfare measure for improvement in management of PNP against status quo is estimated at about MYR 9. Results also showed that demand for better conservation and management of PNP is relatively price-inelastic. Simulations of the results showed, under a MYR10 admission fee, that improvement in management would have 96% of market share compared with status quo. This study concluded that visitor entrance fees can and ought to be introduced as a means of financing conservation initiatives and possibly preventing congestion. Full article

(This article belongs to the Special Issue Ecosystem Services from Forests)

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3398 KiB

Open AccessArticle

Influence of Climate and Economic Variables on the Aggregated Supply of a Wild Edible Fungi (Lactarius deliciosus)

by Oscar Alfranca, Roberto Voces and Luis Diaz-Balteiro

Forests 2015, 6(7), 2324-2344; https://doi.org/10.3390/f6072324 - 6 Jul 2015

Cited by 9 | Viewed by 6511

Abstract

A mycological supply function of wild edible fungi is determined by a set of forest and economic variables, among which climate variables stand out. Focusing on wild mushroom picking with commercial value (Lactarius deliciosus (L.) Gray) as an example, the main objective [...] Read more.

A mycological supply function of wild edible fungi is determined by a set of forest and economic variables, among which climate variables stand out. Focusing on wild mushroom picking with commercial value (Lactarius deliciosus (L.) Gray) as an example, the main objective of this paper is to obtain empirical evidence about the impact of meteorological and economic variables on the mushroom supply. A multidisciplinary vector error correction (VEC) model for mushroom supply is estimated. Coefficients for the Error Correction Term (ECT) are all significant, at the 0.01 significance level, both in the model for prices and for collected mushrooms. The value of the ECT coefficient in the equation for prices is −0.086 (t-value: −9.321), and for the collected mushroom equation is 0.499 (t-value: 3.913). The impact of precipitation on price changes is −0.104 (t-value: −1.66), and the impact of temperature on mushroom harvest picking is 0.605 (t-value: 3.07). We find that including climate factors to explain mushroom supply considerably strengthens the explanatory power of the model, and in some cases greatly changes the results. Full article

(This article belongs to the Special Issue Mycorrhizal Fungi of Forests)

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241 KiB

Open AccessArticle

Enhanced Soil Carbon Storage under Agroforestry and Afforestation in Subtropical China

by Guibin Wang, Clive Welham, Chaonian Feng, Lei Chen and Fuliang Cao

Forests 2015, 6(7), 2307-2323; https://doi.org/10.3390/f6072307 - 1 Jul 2015

Cited by 14 | Viewed by 5655

Abstract

Soil carbon (C) in three Ginkgo (Ginkgo biloba L.) agroforestry systems, afforestation (Ginkgo alone; G), and an agricultural cropping system were compared over a five-year period. The agroforestry systems were Ginkgo + Wheat (Triticum aestivum L.) + Peanut (Arachis hypogaea [...] Read more.

Soil carbon (C) in three Ginkgo (Ginkgo biloba L.) agroforestry systems, afforestation (Ginkgo alone; G), and an agricultural cropping system were compared over a five-year period. The agroforestry systems were Ginkgo + Wheat (Triticum aestivum L.) + Peanut (Arachis hypogaea L.; GWP); Ginkgo + Mulberry (Morus alba L.; GM); and Ginkgo + Rapa (Brassica napus L.) + Peanut (GRP). The agricultural system consisted of wheat and peanut (WP). Total soil carbon (TSC), soil organic (SOC) and inorganic carbon (SIC), and the pools of five SOC chemical fractions were measured. TSC and SOC were always lower under WP than the G-based planting systems, and TSC in the latter increased significantly across years in the top 20 cm. Stocks of SIC under WP were significantly greater than the G-based systems, whereas SOC fractions tended to be lower. Most fractions increased across years but not in WP. Full article

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413 KiB

Open AccessArticle

Variation of Oriental Oak (Quercus variabilis) Leaf δ¹³C across Temperate and Subtropical China: Spatial Patterns and Sensitivity to Precipitation

by Baoming Du, Hongzhang Kang, Yanhua Zhu, Xuan Zhou, Shan Yin, Paul J. Burgess and Chunjiang Liu

Forests 2015, 6(7), 2296-2306; https://doi.org/10.3390/f6072296 - 30 Jun 2015

Cited by 13 | Viewed by 6244

Abstract

The concentration of the carbon-13 isotope (leaf δ¹³C) in leaves is negatively correlated with the mean annual precipitation (MAP) atlarge geographical scales. In this paper, we explain the spatial pattern of leaf δ¹³C variation for deciduous oriental oak ( [...] Read more.

The concentration of the carbon-13 isotope (leaf δ¹³C) in leaves is negatively correlated with the mean annual precipitation (MAP) atlarge geographical scales. In this paper, we explain the spatial pattern of leaf δ¹³C variation for deciduous oriental oak (Quercus variabilis Bl.) across temperate and subtropical biomes and its sensitivity to climate factors such as MAP. There was a 6‰ variation in the leaf δ¹³C values of oak with a significant positive correlation with latitude and negative correlations with the mean annual temperature (MAT) and MAP. There was no correlation between leaf δ¹³C and altitude or longitude. Stepwise multiple regression analyses showed that leaf δ¹³C decreased 0.3‰ per 100 mm increase in MAP. MAP alone could account for 68% of the observed variation in leaf δ¹³C. These results can be used to improve predictions for plant responses to climate change and particularly lower rainfall. Full article

(This article belongs to the Special Issue Responses of Forest Trees to Drought)

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32461 KiB

Open AccessArticle

Adaptation of Leaf Water Relations to Climatic and Habitat Water Availability

by Patrick J. Mitchell and Anthony P. O'Grady

Forests 2015, 6(7), 2281-2295; https://doi.org/10.3390/f6072281 - 30 Jun 2015

Cited by 23 | Viewed by 5815

Abstract

Successful management of forest systems requires a deeper understanding of the role of ecophysiological traits in enabling adaptation to high temperature and water deficit under current and anticipated changes in climate. A key attribute of leaf water relations is the water potential at [...] Read more.

Successful management of forest systems requires a deeper understanding of the role of ecophysiological traits in enabling adaptation to high temperature and water deficit under current and anticipated changes in climate. A key attribute of leaf water relations is the water potential at zero turgor (π_tlp), because it defines the operating water potentials over which plants actively control growth and gas exchange. This study examines the drivers of variation in π_tlp with respect to species climate of origin and habitat water availability. We compiled a water relations database for 174 woody species occupying clearly delineated gradients in temperature and precipitation across the Australian continent. A significant proportion of the variability in π_tlp (~35%) could be explained by climatic water deficit and its interaction with summertime maximum temperature, demonstrating the strong selective pressure of aridity and high temperature in shaping leaf water relations among Australian species. Habitat water availability (midday leaf water potential), was also a significant predictor of π_tlp (R² = 0.43), highlighting the importance of species ecohydrologic niche under a set of climatic conditions. Shifts in π_tlp in response to both climatic and site-based drivers of water availability emphasises its adaptive significance and its suitability as a predictor of plant performance under future climatic change. Full article

(This article belongs to the Special Issue Responses of Forest Trees to Drought)

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Forests, Volume 6, Issue 7 (July 2015) – 12 articles , Pages 2281-2504

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