Forests

Editorial

5 pages, 668 KiB

Open AccessEditorial

Concluding Remarks: Moving Forward on Scientific Knowledge and Management Approaches to Tropical Forests in the Anthropocene Epoch

by Grizelle González and Ariel E. Lugo

Forests 2019, 10(7), 572; https://doi.org/10.3390/f10070572 - 10 Jul 2019

Viewed by 2254

Abstract

The United States Department of Agriculture Forest Service International Institute of Tropical Forestry (the Institute) celebrates its 75th Anniversary with the publication of this Special Issue of Forests. This Issue is based on presentations delivered in a symposium held in San Juan, [...] Read more.

The United States Department of Agriculture Forest Service International Institute of Tropical Forestry (the Institute) celebrates its 75th Anniversary with the publication of this Special Issue of Forests. This Issue is based on presentations delivered in a symposium held in San Juan, Puerto Rico in 2014. It augments a quarter century of scientific knowledge and capitalizes on a unique set of synergies chartered by a strategy based on shared stewardship, innovative transdisciplinary collaborations, and breakthroughs in science and technology. The manuscripts contained here present advancements in our approach to the development of policies for effective governance and stewardship, long-term focus for the understanding of ecosystem processes and functions, novelties given attention to cross-boundary collaborative approaches to science, and proposed alternative institutional visions in the Anthropocene. As the Institute continues to collaboratively explore new frontiers in science, we recognize advances in forestry, atmospheric sciences, modeling, hydrology, plant physiology, and microbial ecology as core to the understanding of tropical forests in the Anthropocene. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

5 pages, 686 KiB

Open AccessEditorial

Introduction to the Special Issue on Tropical Forests: Management and Ecology in the Anthropocene

by Ariel E. Lugo and Grizelle González

Forests 2019, 10(1), 48; https://doi.org/10.3390/f10010048 - 10 Jan 2019

Cited by 1 | Viewed by 3275

Abstract

This Special Issue of Forests is based on papers presented at the 75th anniversary of the United States Department of Agriculture (USDA) Forest Service International Institute of Tropical Forestry as well as other papers relevant to the topic of the Special Issue. The [...] Read more.

This Special Issue of Forests is based on papers presented at the 75th anniversary of the United States Department of Agriculture (USDA) Forest Service International Institute of Tropical Forestry as well as other papers relevant to the topic of the Special Issue. The Institute is but one leg of a conservation relay among cultures and institutions that began in Puerto Rico a millennium ago. The Institute began operations in 1939 and celebrated its 75th anniversary on May, 2014. Over its 75 years of operation, the Institute has focused its research on tropical forests, with the scope of the research expanding over the years. An analysis of the lines of research of the Institute showed that over its history about 69 lines of research have been established and that of the original 17 lines of research between 1939 and 1949, all but one remained active in 2014. This history and continuity of the research program has allowed the Institute to observe ecological phenomena over decades, including the evolving forest structure and functioning on degraded land restoration experiments that began before the formal establishment of the Institute and are now over 80 years old. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

1154 KiB

Open AccessEditorial

Sandra Brown (1944–2017): A Distinguished Tropical Ecologist

by Ariel E. Lugo and Grizelle González

Forests 2017, 8(7), 245; https://doi.org/10.3390/f8070245 - 8 Jul 2017

Viewed by 3780

Abstract

We dedicate this Special Issue commemorating the 75th Anniversary of the US Department of Agriculture, Forest Service—International Institute of Tropical Forestry to the late Dr. Sandra Brown.[...] Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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Research

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4173 KiB

Open AccessArticle

Traits and Resource Use of Co-Occurring Introduced and Native Trees in a Tropical Novel Forest

by Jéssica Fonseca da Silva, Ernesto Medina and Ariel E. Lugo

Forests 2017, 8(9), 339; https://doi.org/10.3390/f8090339 - 12 Sep 2017

Cited by 2 | Viewed by 4597

Abstract

Novel forests are naturally regenerating forests that have established on degraded lands and have a species composition strongly influenced by introduced species. We studied ecophysiological traits of an introduced species (Castilla elastica Sessé) and several native species growing side by side in [...] Read more.

Novel forests are naturally regenerating forests that have established on degraded lands and have a species composition strongly influenced by introduced species. We studied ecophysiological traits of an introduced species (Castilla elastica Sessé) and several native species growing side by side in novel forests dominated by C. elastica in Puerto Rico. We hypothesized that C. elastica has higher photosynthetic capacity and makes more efficient use of resources than co-occurring native species. Using light response curves, we found that the photosynthetic capacity of C. elastica is similar to that of native species, and that different parameters of the curves reflected mostly sun light variation across the forest strata. However, photosynthetic nitrogen use-efficiency as well as leaf area/mass ratios were higher for C. elastica, and both the amount of C and N per unit area were lower, highlighting the different ecological strategies of the introduced and native plants. Presumably, those traits support C. elastica’s dominance over native plants in the study area. We provide empirical data on the ecophysiology of co-occurring plants in a novel forest, and show evidence that different resource-investment strategies co-occur in this type of ecosystem. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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1086 KiB

Open AccessArticle

Adapting Tropical Forest Policy and Practice in the Context of the Anthropocene: Opportunities and Challenges for the El Yunque National Forest in Puerto Rico

by Kathleen A. McGinley

Forests 2017, 8(7), 259; https://doi.org/10.3390/f8070259 - 20 Jul 2017

Cited by 7 | Viewed by 4784

Abstract

Tropical forest management increasingly is challenged by multiple, complex, intersecting, and in many cases unprecedented changes in the environment that are triggered by human activity. Many of these changes are associated with the Anthropocene—a new geologic epoch in which humans have become a [...] Read more.

Tropical forest management increasingly is challenged by multiple, complex, intersecting, and in many cases unprecedented changes in the environment that are triggered by human activity. Many of these changes are associated with the Anthropocene—a new geologic epoch in which humans have become a dominating factor in shaping the biosphere. Ultimately, as human activity increasingly influences systems and processes at multiple scales, we are likely to see more extraordinary and surprising events, making it difficult to predict the future with the level of precision and accuracy needed for broad-scale management prescriptions. In this context of increasing surprise and uncertainty, learning, flexibility, and adaptiveness are essential to securing ecosystem resilience and sustainability, particularly in complex systems such as tropical forests. This article examines the experience to date with and potential for collaborative, adaptive land and resource management in the El Yunque National Forest (EYNF)—the only tropical forest in the U.S. National Forest System. The trajectory of EYNF policy and practice over time and its capacity for learning, flexibility, and adaptiveness to change and surprise are analyzed through an historical institutionalism approach. EYNF policies and practices have shifted from an early custodial approach that focused mostly on protection and prevention to a top-down, technical approach that eventually gave way to an ecosystem approach that has slowly incorporated more flexible, adaptive, and active learning elements. These shifts in EYNF management mostly have been reactive and incremental, with some rarer, rapid changes primarily in response to significant changes in national-level policies, but also to local level conditions and changes in them. Looking to the future, it seems the EYNF may be better positioned than ever before to address increasing uncertainty and surprise at multiple scales. However, it must be able to count on the resources necessary for implementing adaptive, collaborative forest management in a tropical setting and on the institutional and organizational space and flexibility to make swift adjustments or course corrections in response to system changes and surprises. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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680 KiB

Open AccessFeature PaperCommunication

Teams at Their Core: Implementing an “All LANDS Approach to Conservation” Requires Focusing on Relationships, Teamwork Process, and Communications

by Kasey R. Jacobs

Forests 2017, 8(7), 246; https://doi.org/10.3390/f8070246 - 11 Jul 2017

Cited by 7 | Viewed by 4166

Abstract

The U.S. Forest Service has found itself in an era of intense human activity, a changing climate; development and loss of open space; resource consumption; and problematic introduced species; and diversity in core beliefs and values. These challenges test our task-relevant maturity and [...] Read more.

The U.S. Forest Service has found itself in an era of intense human activity, a changing climate; development and loss of open space; resource consumption; and problematic introduced species; and diversity in core beliefs and values. These challenges test our task-relevant maturity and the ability and willingness to meet the growing demands for services. The Forest Service is now on a transformative campaign to improve abilities and meet these challenges. The “All-Lands Approach to Conservation” brings agencies, organizations, landowners and stakeholders together across boundaries to decide on common goals for the landscapes they share. This approach is part of a larger transformation occurring in the American Conservation Movement where large-scale conservation partnerships possibly define the fourth or contemporary era. The intent of this communication is to present one perspective of what large-scale conservation partnerships should include, namely an emphasis on rethinking what leadership looks like in a collaborative context, relational governance, cooperative teamwork procedures, and communications. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

31261 KiB

Open AccessArticle

Land Use, Conservation, Forestry, and Agriculture in Puerto Rico

by William A. Gould, Frank H. Wadsworth, Maya Quiñones, Stephen J. Fain and Nora L. Álvarez-Berríos

Forests 2017, 8(7), 242; https://doi.org/10.3390/f8070242 - 7 Jul 2017

Cited by 32 | Viewed by 15042

Abstract

Global food security concerns emphasize the need for sustainable agriculture and local food production. In Puerto Rico, over 80 percent of food is imported, and local production levels have reached historical lows. Efforts to increase local food production are driven by government agencies, [...] Read more.

Global food security concerns emphasize the need for sustainable agriculture and local food production. In Puerto Rico, over 80 percent of food is imported, and local production levels have reached historical lows. Efforts to increase local food production are driven by government agencies, non-government organizations, farmers, and consumers. Integration of geographic information helps plan and balance the reinvention and invigoration of the agriculture sector while maintaining ecological services. We used simple criteria that included currently protected lands and the importance of slope and forest cover in protection from erosion to identify land well-suited for conservation, agriculture and forestry in Puerto Rico. Within these categories we assessed U.S. Department of Agriculture (USDA) farmland soils classification data, lands currently in agricultural production, current land cover, and current land use planning designations. We found that developed lands occupy 13 percent of Puerto Rico; lands well-suited for conservation that include protected areas, riparian buffers, lands surrounding reservoirs, wetlands, beaches, and salt flats, occupy 45 percent of Puerto Rico; potential working lands encompass 42 percent of Puerto Rico. These include lands well-suited for mechanized and non-mechanized agriculture, such as row and specialty crops, livestock, dairy, hay, pasture, and fruits, which occupy 23 percent of Puerto Rico; and areas suitable for forestry production, such as timber and non-timber products, agroforestry, and shade coffee, which occupy 19 percent of Puerto Rico. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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6513 KiB

Open AccessCommunication

Insights on Forest Structure and Composition from Long-Term Research in the Luquillo Mountains

by Tamara Heartsill Scalley

Forests 2017, 8(6), 204; https://doi.org/10.3390/f8060204 - 10 Jun 2017

Cited by 17 | Viewed by 6488

Abstract

The science of ecology fundamentally aims to understand species and their relation to the environment. At sites where hurricane disturbance is part of the environmental context, permanent forest plots are critical to understand ecological vegetation dynamics through time. An overview of forest structure [...] Read more.

The science of ecology fundamentally aims to understand species and their relation to the environment. At sites where hurricane disturbance is part of the environmental context, permanent forest plots are critical to understand ecological vegetation dynamics through time. An overview of forest structure and species composition from two of the longest continuously measured tropical forest plots is presented. Long-term measurements, 72 years at the leeward site, and 25 years at windward site, of stem density are similar to initial and pre-hurricane values at both sites. For 10 years post-hurricane Hugo (1989), stem density increased at both sites. Following that increase period, stem density has remained at 1400 to 1600 stems/ha in the leeward site, and at 1200 stems/ha in the windward site. The forests had similar basal area values before hurricane Hugo in 1989, but these sites are following different patterns of basal area accumulation. The leeward forest site continues to accumulate and increase basal area with each successive measurement, currently above 50 m²/ha. The windward forest site maintains its basal area values close to an asymptote of 35 m²/ha. Currently, the most abundant species at both sites is the sierra palm. Ordinations to explore variation in tree species composition through time present the leeward site with a trajectory of directional change, while at the windward site, the composition of species seems to be converging to pre-hurricane conditions. The observed differences in forest structure and composition from sites differently affected by hurricane disturbance provide insight into how particular forest characteristics respond at shorter or longer time scales in relation to previous site conditions and intensity of disturbance effects. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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1048 KiB

Open AccessCommunication

How Cities Think: Knowledge Co-Production for Urban Sustainability and Resilience

by Tischa A. Muñoz-Erickson, Clark A. Miller and Thaddeus R. Miller

Forests 2017, 8(6), 203; https://doi.org/10.3390/f8060203 - 10 Jun 2017

Cited by 89 | Viewed by 19861

Abstract

Understanding and transforming how cities think is a crucial part of developing effective knowledge infrastructures for the Anthropocene. In this article, we review knowledge co-production as a popular approach in environmental and sustainability science communities to the generation of useable knowledge for sustainability [...] Read more.

Understanding and transforming how cities think is a crucial part of developing effective knowledge infrastructures for the Anthropocene. In this article, we review knowledge co-production as a popular approach in environmental and sustainability science communities to the generation of useable knowledge for sustainability and resilience. We present knowledge systems analysis as a conceptual and empirical framework for understanding existing co-production processes as preconditions to the design of new knowledge infrastructures in cities. Knowledge systems are the organizational practices and routines that make, validate, communicate, and apply knowledge. The knowledge systems analysis framework examines both the workings of these practices and routines and their interplay with the visions, values, social relations, and power dynamics embedded in the governance of building sustainable cities. The framework can be useful in uncovering hidden relations and highlighting the societal foundations that shape what is (and what is not) known by cities and how cities can co-produce new knowledge with meaningful sustainability and resilience actions and transformations. We highlight key innovations and design philosophies that we think can advance research and practice on knowledge co-production for urban sustainability and resilience. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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1896 KiB

Open AccessArticle

Substrate Chemistry and Rainfall Regime Regulate Elemental Composition of Tree Leaves in Karst Forests

by Ernesto Medina, Elvira Cuevas and Ariel E. Lugo

Forests 2017, 8(6), 182; https://doi.org/10.3390/f8060182 - 25 May 2017

Cited by 10 | Viewed by 4818

Abstract

Forests on calcareous substrates constitute a large fraction of the vegetation in Puerto Rico. Plant growth on these substrates may be affected by nutrient deficiencies, mainly P and Fe, resulting from high pH and formation of insoluble compounds of these elements. The occurrence [...] Read more.

Forests on calcareous substrates constitute a large fraction of the vegetation in Puerto Rico. Plant growth on these substrates may be affected by nutrient deficiencies, mainly P and Fe, resulting from high pH and formation of insoluble compounds of these elements. The occurrence of these forests in humid and dry areas provides an opportunity to compare nutrient relations, water use efficiency, and N dynamics, using biogeochemical parameters. We selected sites under humid climate in the north, and dry climate in the southwest of Puerto Rico. Adult, healthy leaves of species with high importance values were collected at each site and analyzed for their elemental composition and the natural abundance of C and N isotopes. Calcium was the dominant cation in leaf tissues, explaining over 70% of the ash content variation, and Al and Ca concentration were positively correlated, excepting only two Al-accumulating species. Karst vegetation consistently showed high N/P ratios comparable to forests on P-poor soils. Dry karst sites had significantly higher δ¹³C and δ¹⁵N ratios. We conclude that forests on karst are mainly limited by P availability, and that mechanisms of nutrient uptake in the rhizosphere lead to linear correlations in the uptake of Ca and Al. Isotope ratios indicate higher water use efficiency, and predominant denitrification in dry karst forest sites. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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699 KiB

Open AccessArticle

The Plight of Migrant Birds Wintering in the Caribbean: Rainfall Effects in the Annual Cycle

by Joseph M. Wunderle, Jr. and Wayne J. Arendt

Forests 2017, 8(4), 115; https://doi.org/10.3390/f8040115 - 8 Apr 2017

Cited by 5 | Viewed by 4877

Abstract

Here, we summarize results of migrant bird research in the Caribbean as part of a 75th Anniversary Symposium on research of the United States Department of Agriculture Forest Service, International Institute of Tropical Forestry (IITF). The fate of migratory birds has been a [...] Read more.

Here, we summarize results of migrant bird research in the Caribbean as part of a 75th Anniversary Symposium on research of the United States Department of Agriculture Forest Service, International Institute of Tropical Forestry (IITF). The fate of migratory birds has been a concern stimulating research over the past 40 years in response to population declines documented in long-term studies including those of the IITF and collaborators in Puerto Rico’s Guánica dry forest. Various studies indicate that in addition to forest loss or fragmentation, some migrant declines may be due to rainfall variation, the consequences of which may carry over from one stage of a migrant’s annual cycle to another. For example, the Guánica studies indicate that rainfall extremes on either the temperate breeding or tropical wintering grounds affect migrant abundance and survival differently depending on the species. In contrast, IITF’s collaborative studies of the migrant Kirtland’s Warbler (Setophaga kirtlandii) in the Bahamas found that late winter droughts affect its annual survival and breeding success in Michigan. We review these IITF migrant studies and relate them to other studies, which have improved our understanding of migrant ecology of relevance to conservation. Particularly important is the advent of the full annual cycle (FAC) approach. The FAC will facilitate future identification and mitigation of limiting factors contributing to migrant population declines, which for some species, may be exacerbated by global climate change. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

834 KiB

Open AccessArticle

The Dynamics of Deforestation in the Wet and Dry Tropics: A Comparison with Policy Implications

by Thomas K. Rudel

Forests 2017, 8(4), 108; https://doi.org/10.3390/f8040108 - 5 Apr 2017

Cited by 47 | Viewed by 5816

Abstract

Forests in the dry tropics differ significantly from forests in the humid tropics in their biomass and in their socio-ecological contexts, so it might be reasonable to assume that the dynamics that drive deforestation in these two settings would also differ. Until recently, [...] Read more.

Forests in the dry tropics differ significantly from forests in the humid tropics in their biomass and in their socio-ecological contexts, so it might be reasonable to assume that the dynamics that drive deforestation in these two settings would also differ. Until recently, difficulties in measuring the extent of dry tropical forests have made it difficult to investigate this claim empirically. The release of high resolution LANDSAT satellite imagery in 2013 has removed this impediment, making it possible to identify variations in the extent of wet and dry forests within countries by measuring variations in the canopy cover of their forests. These metrics have in turn made it possible to investigate human differences in the dynamics of deforestation between dry forested and wet forested nations in the tropics. Cross-national analyses suggest that international trade in agricultural commodities plays a more important role in driving deforestation in the wet tropics than it does in the dry tropics. The variable salience of international trade as a driver has important implications, described here, for the success of policies designed to slow deforestation in the dry tropics and the wet tropics. Curbing dry forest losses, in particular, would appear to require locally focused and administered policies. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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Review

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18 pages, 7754 KiB

Open AccessReview

On the Shoulders of Giants: Continuing the Legacy of Large-Scale Ecosystem Manipulation Experiments in Puerto Rico

by Tana E. Wood, Grizelle González, Whendee L. Silver, Sasha C. Reed and Molly A. Cavaleri

Forests 2019, 10(3), 210; https://doi.org/10.3390/f10030210 - 27 Feb 2019

Cited by 7 | Viewed by 6664

Abstract

There is a long history of experimental research in the Luquillo Experimental Forest in Puerto Rico. These experiments have addressed questions about biotic thresholds, assessed why communities vary along natural gradients, and have explored forest responses to a range of both anthropogenic and [...] Read more.

There is a long history of experimental research in the Luquillo Experimental Forest in Puerto Rico. These experiments have addressed questions about biotic thresholds, assessed why communities vary along natural gradients, and have explored forest responses to a range of both anthropogenic and non-anthropogenic disturbances. Combined, these studies cover many of the major disturbances that affect tropical forests around the world and span a wide range of topics, including the effects of forest thinning, ionizing radiation, hurricane disturbance, nitrogen deposition, drought, and global warming. These invaluable studies have greatly enhanced our understanding of tropical forest function under different disturbance regimes and informed the development of management strategies. Here we summarize the major field experiments that have occurred within the Luquillo Experimental Forest. Taken together, results from the major experiments conducted in the Luquillo Experimental Forest demonstrate a high resilience of Puerto Rico’s tropical forests to a variety of stressors. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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737 KiB

Open AccessFeature PaperReview

Soil Biology Research across Latitude, Elevation and Disturbance Gradients: A Review of Forest Studies from Puerto Rico during the Past 25 Years

by Grizelle González and D. Jean Lodge

Forests 2017, 8(6), 178; https://doi.org/10.3390/f8060178 - 24 May 2017

Cited by 16 | Viewed by 6041

Abstract

Progress in understanding changes in soil biology in response to latitude, elevation and disturbance gradients has generally lagged behind studies of above-ground plants and animals owing to methodological constraints and high diversity and complexity of interactions in below-ground food webs. New methods have [...] Read more.

Progress in understanding changes in soil biology in response to latitude, elevation and disturbance gradients has generally lagged behind studies of above-ground plants and animals owing to methodological constraints and high diversity and complexity of interactions in below-ground food webs. New methods have opened research opportunities in below-ground systems, leading to a rapid increase in studies of below-ground organisms and processes. Here, we summarize results of forest soil biology research over the past 25 years in Puerto Rico as part of a 75th Anniversary Symposium on research of the USDA Forest Service International Institute of Tropical Forestry. These results are presented in the context of changes in soil and forest floor biota across latitudinal, elevation and disturbance gradients. Invertebrate detritivores in these tropical forests exerted a stronger influence on leaf decomposition than in cold temperate forests using a common substrate. Small changes in arthropods brought about using different litterbag mesh sizes induced larger changes in leaf litter mass loss and nutrient mineralization. Fungi and bacteria in litter and soil of wet forests were surprisingly sensitive to drying, leading to changes in nutrient cycling. Tropical fungi also showed sensitivity to environmental fluctuations and gradients as fungal phylotype composition in soil had a high turnover along an elevation gradient in Puerto Rico. Globally, tropical soil fungi had smaller geographic ranges than temperate fungi. Invertebrate activity accelerates decomposition of woody debris, especially in lowland dry forest, but invertebrates are also important in early stages of log decomposition in middle elevation wet forests. Large deposits of scoltine bark beetle frass from freshly fallen logs coincide with nutrient immobilization by soil microbial biomass and a relatively low density of tree roots in soil under newly fallen logs. Tree roots shifted their foraging locations seasonally in relation to decaying logs. Native earthworms were sensitive to disturbance and were absent from tree plantations, whereas introduced earthworms were found across elevation and disturbance gradients. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

2269 KiB

Open AccessFeature PaperReview

Novelty and Its Ecological Implications to Dry Forest Functioning and Conservation

by Ariel E. Lugo and Heather E. Erickson

Forests 2017, 8(5), 161; https://doi.org/10.3390/f8050161 - 10 May 2017

Cited by 7 | Viewed by 4246

Abstract

Tropical and subtropical dry forest life zones support forests with lower stature and species richness than do tropical and subtropical life zones with greater water availability. The number of naturalized species that can thrive and mix with native species to form novel forests [...] Read more.

Tropical and subtropical dry forest life zones support forests with lower stature and species richness than do tropical and subtropical life zones with greater water availability. The number of naturalized species that can thrive and mix with native species to form novel forests in dry forest conditions in Puerto Rico and the US Virgin Islands is lower than in other insular life zones. These novel dry forests are young (<60 years) with low structural development, high species dominance, and variable species density. Species density is low during initial establishment and increases with age. At the 1-ha scale, novel forests can have greater species density than mature native forests. Species groups, such as nitrogen-fixing species, and other naturalized species that dominate novel dry forests, have a disproportional influence on forest element stoichiometry. Novel dry forests, compared to the mean of all forest species assemblages island-wide, tend to have fallen leaf litter with lower than average manganese and sodium concentrations and lower than average C/N and C/P ratios. After accounting for significant differences in stand age, geology, and or precipitation, novel dry forests compared to native dry forests have higher C anomalies, lower Ca and Na anomalies, and lower C/N ratio anomalies. Taken together, these characteristics may influence litter decomposition rates and the species composition, diversity, and food web dynamics in litter and soil. Novel dry forests also contribute to the conservation of native plant species on highly degraded lands. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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2149 KiB

Open AccessReview

Trailblazing the Carbon Cycle of Tropical Forests from Puerto Rico

by Sandra Brown and Ariel E. Lugo

Forests 2017, 8(4), 101; https://doi.org/10.3390/f8040101 - 29 Mar 2017

Cited by 13 | Viewed by 7129

Abstract

We review the literature that led to clarifying the role of tropical forests in the global carbon cycle from a time when they were considered sources of atmospheric carbon to the time when they were found to be atmospheric carbon sinks. This literature [...] Read more.

We review the literature that led to clarifying the role of tropical forests in the global carbon cycle from a time when they were considered sources of atmospheric carbon to the time when they were found to be atmospheric carbon sinks. This literature originates from work conducted by US Forest Service scientists in Puerto Rico and their collaborators. It involves the classification of forests by life zones, estimation of carbon density by forest type, assessing carbon storage changes with ecological succession and land use/land cover type, describing the details of the carbon cycle of forests at stand and landscape levels, assessing global land cover by forest type and the complexity of land use change in tropical regions, and assessing the ecological fluxes and storages that contribute to net carbon accumulation in tropical forests. We also review recent work that couples field inventory data, remote sensing technology such as LIDAR, and GIS analysis in order to more accurately determine the role of tropical forests in the global carbon cycle and point out new avenues of carbon research that address the responses of tropical forests to environmental change. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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Other

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1594 KiB

Open AccessCommentary

A Forest Service Vision during the Anthropocene

by Michael T. Rains

Forests 2017, 8(3), 94; https://doi.org/10.3390/f8030094 - 22 Mar 2017

Cited by 3 | Viewed by 4716

Abstract

During the history of the Forest Service, human activity has been the dominant influence on climate and the environment; the time being called the Anthropocene. As we look ahead and strive to continue our mission of sustaining the health, diversity, and productivity [...] Read more.

During the history of the Forest Service, human activity has been the dominant influence on climate and the environment; the time being called the Anthropocene. As we look ahead and strive to continue our mission of sustaining the health, diversity, and productivity of the Nation’s forests and grasslands to meet our current and future needs, we must be more flexible to focus our actions to better meet the contemporary conservation challenges now and ahead. During this era of intense human activity, a changing climate; development and loss of open space; resource consumption; destructive invasive species; and diversity in core beliefs and values will test our task relevant maturity—ability and willingness to meet the growing demands for services. The Forest Service is now on a transformative campaign to improve our abilities and meet these challenges, including forest resiliency through restorative actions. There are several things we must do to ensure we are brilliantly competitive to address the contemporary conservation needs along a complex rural to urban land gradient, now and ahead. The intent of this paper is to present one person’s view of what this “campaign of our campaign” should include. Full article

(This article belongs to the Special Issue Tropical Forest Ecology and Management for the Anthropocene)

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