Tropical Forest Conservation Research Articles

Patterns of tree community differences in the core and buffer zones of a nature reserve in north-western Vietnam

In tropical forest conservation, areas with full statutory protection are often surrounded by buffer zones. Information on the patterns of tree community structure differences in these zones is helpful to evaluate the conservation efficacy. Our study was implemented within a biodiversity hotspot, in the Ta Xua Nature Reserve of north-western Vietnam, which has a statutorily protected core zone and a buffer zone, where local H’Mong people are permitted low intensity forest use. The forests are rich in tree species (249 observed). Many of these tree species provide non-timber forest products (NTFPs) (48%) or valuable timber (22%), and 18 species are red-listed. Overall tree density was not different in the two zones, but tree diameter and species richness were lower in the buffer zone. At the tree level, logistic regression analysis indicated that red-listed status, large diameter, and low density of conspecifics increased the probability of tree absence from the buffer zone but not the potential use as a NTFP. However, most NTFP species had different densities in the core and buffer zones, and this correlated with signs of human interference. At the species level, the density of species was the most important variable, and rarity strongly increased the probability of species absence. Our results also indicate that rare and red-listed trees were depleted in the buffer zone. In consideration of conservation goals, the future monitoring of these species at the Ta Xua Nature Reserve and other protected areas is needed, and conservation measures most likely need to be improved.

Branchfall dominates annual carbon flux across lowland Amazonian forests

Tropical forests play an important role in the global carbon cycle, but knowledge of interannual variation in the total tropical carbon flux and constituent carbon pools is highly uncertain. One such pool, branchfall, is an ecologically important dynamic with links to nutrient cycling, forest productivity, and drought. Identifying and quantifying branchfall over large areas would reveal the role of branchfall in carbon and nutrient cycling. Using data from repeat airborne light detection and ranging campaigns across a wide array of lowland Amazonian forest landscapes totaling nearly 100 000 ha, we find that upper canopy gaps—driven by branchfall—are pervasive features of every landscape studied, and are seven times more frequent than full tree mortality. Moreover, branchfall comprises a major carbon source on a landscape basis, exceeding that of tree mortality by 21%. On a per hectare basis, branchfall and tree mortality result in 0.65 and 0.72 Mg C ha−1 yr−1 gross source of carbon to the atmosphere, respectively. Reducing uncertainties in annual gross rates of tropical forest carbon flux, for example by incorporating large-scale branchfall dynamics, is crucial for effective policies that foster conservation and restoration of tropical forests. Additionally, large-scale branchfall mapping offers ecologists a new dimension of disturbance monitoring and potential new insights into ecosystem structure and function.

The implementation costs of forest conservation policies in Brazil

Tropical forest conservation is considered a low-cost option for climate change mitigation. But mitigation cost assessments have featured opportunity costs, neglecting policy implementation costs. Here we use official data to identify the Brazilian federal government's operational and institutional budgets related to forest conservation policies implemented from 2000 to 2014. We distinguish the allocated and executed budgets of these policies, and provide scenario-based estimates of their cost-effectiveness. On average, Brazil spent US$ 1billion/year on forest conservation policies at the federal level. Brazil's substantial reduction in annual forest loss after 2004 was accompanied by a higher operational budget execution of disincentive-based policy instruments, and an absolute increase in both allocated and executed institutional budgets. The post-2004 successful mitigation effort represented additional implementation costs to the Brazilian federal government of US$ 308–923/ha of avoided deforestation, or US$ 0.87–2.60/tCO2 of avoided emissions. Factoring in also approximate municipal and state expenditures, these costs increase to US$ 385–1153/ha or US$ 1.09–3.25/tCO2. We conclude that implementations costs are non-trivial in size, including compared to estimates of land users' opportunity costs. This has important implications for REDD+ policy design, in the sense that implementation costs need to be adequately considered.

Habitat fragmentation and the future structure of tree assemblages in a fragmented Atlantic forest landscape

The biodiversity value of human-modified landscapes has become a central question in the tropical forest conservation biology, yet the degree to which plant populations and communities are restructured in response to environmental change remains unclear. Here, we address tree species density in a fragmented Atlantic forest landscape to test the hypothesis that tree assemblages inhabiting edge-dominated forest habitats approach typical conditions of early successional systems. Seedlings and adults from 141 tree species were sampled across 39 0.1-ha plots: 19 in small fragments ( 55 % of all tree species exhibiting higher densities in small fragments than in mature forest, particularly pioneers (>60 % of all species). Seedlings and adults of these proliferating species differed from species exhibiting population declines in terms of wood density and seed size, respectively. Additionally, pioneers were more abundant than shade-tolerant species, as were hardwood species in the case of seedlings. Tree species showing highest population increases consisted largely of long-lived, light-demanding canopy species bearing soft or hardwood and small-to-medium-sized seeds. Tree assemblage structure also differed in terms of forest habitats with small forest fragments supporting few rare species, whereas the most rapidly proliferating species were much more widespread and abundant in fragments. However, 60 % of all adult pioneer species recorded in small fragments were not recorded as seedlings in this habitat type, although both seedling and adult assemblages were dominated by pioneer species. Edge-dominated tree assemblages are likely to experience long-term shifts toward greater dominance of long-lived, pioneer canopy species.

Spatially explicit analysis of field inventories for national forest carbon monitoring.

BackgroundTropical forests provide a crucial carbon sink for a sizable portion of annual global CO2 emissions. Policies that incentivize tropical forest conservation by monetizing forest carbon ultimately depend on accurate estimates of national carbon stocks, which are often based on field inventory sampling. As an exercise to understand the limitations of field inventory sampling, we tested whether two common field-plot sampling approaches could accurately estimate carbon stocks across approximately 76 million ha of Perúvian forests. A 1-ha resolution LiDAR-based map of carbon stocks was used as a model of the country’s carbon geography.ResultsBoth field inventory sampling approaches worked well in estimating total national carbon stocks, almost always falling within 10 % of the model national total. However, the sampling approaches were unable to produce accurate spatially-explicit estimates of the carbon geography of Perú, with estimates falling within 10 % of the model carbon geography across no more than 44 % of the country. We did not find any associations between carbon stock errors from the field plot estimates and six different environmental variables.ConclusionsField inventory plot sampling does not provide accurate carbon geography for a tropical country with wide ranging environmental gradients such as Perú. The lack of association between estimated carbon errors and environmental variables suggests field inventory sampling results from other nations would not differ from those reported here. Tropical forest nations should understand the risks associated with primarily field-based sampling approaches, and consider alternatives leading to more effective forest conservation and climate change mitigation.Electronic supplementary materialThe online version of this article (doi:10.1186/s13021-016-0050-0) contains supplementary material, which is available to authorized users.

REQUIREMENTS FOR THE SUSTAINABLE DEVELOPMENT OF ECONOMIC ACTIVITIES IN TROPICAL FOREST COMMUNITIES

Tropical forests are storing carbon in their biomass, supporting biodiversity, acting as sources for timber and Non Timber Forest Products, and are the habitat for forest communities. For centuries, most tropical forest communities maintained sustainable forest management, which has led to the sustainment of their living conditions and to an important contribution to the conservation of the environment and the climate. In the last decades this is increasingly threatened by the commercial timber industry which plunders the tropical forests for the extraction of valuable timber. In this paper we propose a concept of how sustainable development concept can be applied to the living conditions of tropical forest communities. We answer the question of how sustainable development of economic activities for forest communities’ inhabitants can be achieved including improvement of their living standard and conservation of tropical forests. We formalize qualitative causal relations and conclude that sustainable development in forest communities cannot be achieved without 1. legal rights for forest management, 2. targeted investments and initial capital for the organization of economic activities with ecological and social responsibility, and 3. organizational, technical, and methodical support. Keywords: sustainable development; tropical forest communities; small scale forest enterprises; social responsibility

Importance of Non Timber Forest Production in Sustainable Forest Management and Its Implication on Carbon Storage and Biodiversity Conservation in Case of Ethiopia

Non-timber forest products (NTFPs) are biological resources of plant and animal origin, harvested from natural forests, manmade plantations, wooded land, farmlands, and trees outside forests and or domesticated. These products are vital sources of income, nutrition and sustenance for many forest-based communities around the world. This paper tries to review available and accessible literatures on role of NTFPs in sustainable forest management and its implication on carbon storage and Biodiversity conservation in case of Ethiopia. Including Sociological Approach, Economic Approach, Ecosystem Approach, Technological Approach and its related services (biodiversity conservation and carbon sequestration). The use of Non Timber Forest Products (NTFPs) has received attention in light of their Perceived potential to address both poverty reduction and tropical forest conservation. Moreover, management of NTFPs, factors that hamper sustainable managements of NTFPs. It was suggested that better management and utilization method has to be set for diversifying products benefit for the local community.

Tree species diversity, distribution and population structure in a tropical dry deciduous forests of Chhatisgarh, India

Tree species diversity, distribution and population structure of tropical forests of Bharnawapara wildlife sanctuary was investigated. The study analyzed the structure of a tropical dry deciduous forest in Chhatisgarh at different sites i.e. closed natural forest, open natural forest and plantation forests of teak. The study was conducted by laying 30 quadrats, each 10 m × 10 m in size at different sites. In total, 246 trees belonging to 28 species of 17 families were recorded from 0.3 ha sampling area. Density ranged between 520 to 990 trees ha-1 subsequently, basal area ranged between 21.50 to 47.30 m2 ha-1. The dominant tree species was Cleistanthus collinus with an importance value index (IVI) of 57.70. Other important species were Terminalia tometosa (IVI 47.10), Lagerstroemia parviflora (36.92), Diospyros melanoxylon (28.42) and Madhuca indica(26.03). The Shannon-Wiener index (H?) ranged between 0.19 to 3.35 and Simpson’s index (C) between 0.12 to 0.95 indicating high tree species diversity of tropical dry deciduous forests. It is evident from the study that natural forest has an edge over plantation forest in terms of species diversity, dominance and richness. Tree species diversity, distribution and population structure provide baseline information for conservation and management of tropical dry deciduous forests in India. Efforts are needed to conserve the natural forest for their diversity and existence. They can also be supplemented with plantation forests to lower the biotic pressure.

Enhancing Ecosystem Function through Conservation: Threatened Plants Increase Local Carbon Storage in Tropical Dry Forests

The role of plant diversity, particularly of rare species, in ecosystem functioning ( e.g., carbon storage) has been mostly studied in temperate systems with little practical application to the conservation of tropical forests, where species rarity and species richness tend to be greater and more important for ecosystem functioning. We linked carbon storage pools with functional plant diversity, occurrence of rare species, and environmental (topographic) gradients in a species-rich seasonally dry tropical forest protected as a part of a Biosphere Reserve in northwestern Mexico. We estimated various functional diversity and carbon pool measures from in situ plant community and soil data. Soil and total ecosystem carbon storage decreased with slope steepness but increased with plant height. Above-ground carbon was negatively associated with elevation. Our data suggest that species identity matters to the functioning and productivity of seasonally dry tropical forests. Two long-lived and highly threatened rare plant species contributed considerably (10-20%) to the above-ground carbon storage pool. The functional roles of threatened plant species should be investigated and incorporated into the management plans of Biospheres Reserves and other closely coupled natural-human systems, where conservation plays a significant role in ecosystem functioning and human well-being.

Environmental Conservation for Food Production and Sustainable Livelihood in Tropical Africa

Abstract The Special Issue of Land Degradation and Development on “environmental conservation for food production and sustainable livelihood in tropical Africa” holds 14 case studies regarding vegetation cover and physical soil and water conservation in tropical Africa. Studies on forest conservation include varied vegetation types such as Boswellia and Erica forests or fuelwood plantations. Physical soil and water conservation studies in this Special Issue particularly concern on-site effects on soil fertility and off-site effects related to hydro(geomorpho)logy. Last but not least, studies on rates and reasons of adoption of conservation measures by mostly smallholder farmers are presented. Key words : tropical forest, soil and water conservation, adoption of innovations, smallholder farmers, water balance, sediment budget Introduction Whereas, geographically, the tropics contain all regions situated between 23°N and 23°S, we here define it using temperature: regions where the average temperature over the year is higher than 15°C, where intra-annual variability of the day temperature is relatively small, and where no frost occurs. In addition, elevated regions such as “High Africa” (

From evergreen to deciduous tropical forests: how energy–water balance, temperature, and space influence the tree species composition in a high diversity region

Background: Understanding floristic and geographic patterns in one of the most biodiverse regions in the world – the Atlantic forest of eastern Bahia, Brazil – can identify the drivers of diversity in tropical forests and provide useful information for biological conservation.Aims: To understand the role of both climate and geographical location on variation in tree species composition in a region characterised by an abrupt transition from wet forests to semi-arid thorn-woodlands. To test whether a regional classification of forests according to elevation belts and leaf flush pattern is consistent with floristic composition.Methods: We submitted 14,094 tree species occurrence records and 31 geo-climatic variables prepared for 57 sites in eastern Bahia, Brazil, to multivariate and regression analyses and variance partitioning.Results: Climate and space were both significantly (P ≤ 0.05) contributing to explaining floristic variations. Actual evapotranspiration, duration of water deficit, and minimum temperature of coldest month were the main predictors. Floristic differences were significant except when comparing evergreen lower plains and upper plains forests.Conclusions: Although distance among sites may play an important role, species composition is chiefly influenced by environmental gradients. This highlights environmental heterogeneity as a key factor in the planning of biodiversity conservation in tropical forests.

Selective logging: Do rates of forest turnover in stems, species composition and functional traits decrease with time since disturbance? – A 45 year perspective

Selective logging, the targeted harvesting of timber trees in a single cutting cycle, is globally rising in extent and intensity. Short-term impacts of selective logging on tropical forests have been widely investigated, but long-term effects on temporal dynamics of forest structure and composition are largely unknown. Understanding these long-term dynamics will help determine whether tropical forests are resilient to selective logging and inform choices between competing demands of anthropogenic use versus conservation of tropical forests. Forest dynamics can be studied within the framework of succession theory, which predicts that temporal turnover rates should decline with time since disturbance. Here, we investigated the temporal dynamics of a tropical forest in Kibale National Park, Uganda over 45years following selective logging. We estimated turnover rates in stems, species composition, and functional traits (wood density and diameter at breast height), using observations from four censuses in 1989, 1999, 2006, and 2013, of stems ⩾10cm diameter within 17 unlogged and 9 logged 200×10m vegetation plots. We used null models to account for interdependencies among turnover rates in stems, species composition, and functional traits. We tested predictions that turnover rates should be higher and decrease with increasing time since the selective logging event in logged forest, but should be less temporally variable in unlogged forest. Overall, we found higher turnover rates in logged forest for all three attributes, but turnover rates did not decline through time in logged forest and was not less temporally variable in unlogged forest. These results indicate that successional models that assume recovery to pre-disturbance conditions are inadequate for predicting the effects of selective logging on the dynamics of the tropical forest in Kibale. Selective logging resulted in persistently higher turnover rates, which may compromise the carbon storage capacity of Kibale’s forest. Selective logging effects may also interact with effects from other global trends, potentially causing major long-term shifts in the dynamics of tropical forests. Similar studies in tropical forests elsewhere will help determine the generality of these conclusions. Ultimately, the view that selective logging is a benign approach to the management of tropical forests should be reconsidered in the light of studies of the effects of this practice on long-term forest dynamics.

Forests as Capital: Financial Mechanisms for Tropical Forest Conservation

Tropical forest loss and degradation due to human activities have been persistent and intractable global problems. Model estimates suggest that current levels of finance for conservation and sustainable forest management (SFM) are insufficient and may need to increase by an order of magnitude in order to meet this challenge. This special issue presents select articles from the 2014 Yale International Society of Tropical Foresters (ISTF) Annual Conference, which explored diverse finance mechanisms such as REDD+, sustainability certification, ecological compensation, community forestry, and official development assistance. Each finance mechanism has advantages and disadvantages, which render them effective under specific circumstances. Comprehensive tropical forest conservation will require a diverse portfolio of finance strategies appropriate for local institutional and ecological conditions. Hybrid strategies combining elements of multiple schemes could bolster conservation and SFM efforts by leveraging their respective strengths. Clear and realistic targets and baselines, robust monitoring and measurement-reporting-verification, strong governance and institutions, and periodic evaluation can contribute to the successful application of forest conservation finance. Due to the potentially high damages, especially to the world’s poorest communities from continuing current deforestation trends, substantially greater financing of tropical conservation and SFM is a sound global investment.

Aboveground carbon loss in natural and managed tropical forests from 2000 to 2012

Tropical forests provide global climate regulation ecosystem services and their clearing is a significant source of anthropogenic greenhouse gas (GHG) emissions and resultant radiative forcing of climate change. However, consensus on pan-tropical forest carbon dynamics is lacking. We present a new estimate that employs recommended good practices to quantify gross tropical forest aboveground carbon (AGC) loss from 2000 to 2012 through the integration of Landsat-derived tree canopy cover, height, intactness and forest cover loss and GLAS-lidar derived forest biomass. An unbiased estimate of forest loss area is produced using a stratified random sample with strata derived from a wall-to-wall 30 m forest cover loss map. Our sample-based results separate the gross loss of forest AGC into losses from natural forests (0.59 PgC yr−1) and losses from managed forests (0.43 PgC yr−1) including plantations, agroforestry systems and subsistence agriculture. Latin America accounts for 43% of gross AGC loss and 54% of natural forest AGC loss, with Brazil experiencing the highest AGC loss for both categories at national scales. We estimate gross tropical forest AGC loss and natural forest loss to account for 11% and 6% of global year 2012 CO2 emissions, respectively. Given recent trends, natural forests will likely constitute an increasingly smaller proportion of tropical forest GHG emissions and of global emissions as fossil fuel consumption increases, with implications for the valuation of co-benefits in tropical forest conservation.

Comparative effectiveness of silvicultural interventions for increasing timber production and sustaining conservation values in natural tropical production forests. A systematic review protocol

Background: Currently, about 400 million hectares of tropical moist forests worldwide are designated production forests, about a quarter of which are managed by rural communities and indigenous peoples. There has been a gradual impoverishment of forest resources inside selectively logged forests in which the volume of timber extracted over the first cutting cycle was mostly from large, old trees that matured over a century or more and grew in the absence of strong anthropological pressures. In forests now being logged for a second and third time, that volume has not been reconstituted due in part to the lack of implementation of post-logging silvicultural treatments. This depletion of timber stocks renders the degraded forests prone to conversion to other land uses. Although it is essential to preserve undisturbed primary forests through the creation of protected areas, these areas alone will not be able to ensure the conservation of all species on a pan-tropical scale, for social, economic and political reasons. The conservation of tropical forests of tomorrow will mostly take place within human-modified (logged, domesticated) forests. In this context, silvicultural interventions are considered by many tropical foresters and forest ecologists as tools capable of effectively conserving tropical forest biodiversity and ecosystem services while stimulating forest production. This systematic review aims to assess past and current evidence of the impact of silviculture on tropical forests and to identify silvicultural practices appropriate for the current conditions in the forests and forestry sectors of the Congo Basin, Amazonia and Southeast Asia. Methods: This systematic review will undertake an extensive search of literature to assess the relative effectiveness of different silvicultural interventions on timber production and the conservation value of forests, and to determine whether there is a relationship between sustainability of timber harvesting and the maintenance/conservation of other ecosystem services and biodiversity in production forests. Data will be extracted for meta-analysis of at least sub-sets of the review questions. Findings are expected to help inform policy and develop evidence-based practice guidelines on silvicultural practices in tropical forests.

Tropical forest conservation versus conversion trade-offs: Insights from analysis of ecosystem services provided by Kakamega rainforest in Kenya

Ecosystem services provided by tropical forests are becoming scarcer due to continued deforestation as demand for forest benefits increases with the growing population. There is need for comprehensive valuation of key ecosystem services in order to inform policy and implement better management systems to enhance the supply of ecosystem services. This study estimates local economic value of key ecosystem services provided by Kakamega rainforest and examines how the information can support sustainable forest management in Kenya. This is the only rainforest in Kenya and it has exceptional biodiversity value including several unique species not found anywhere else in the country. Kakamega rainforest also provides a classic case of conflict between conservation and exploitation goals given the dense population around it. We carried out elaborate household and visitors surveys to collect data used to estimate the economic value of three main ecosystem services. We estimated the total economic value of key ecosystem services (excluding biodiversity value) at about US$ 7.4 million per year or US$ 415ha−1yr−1. The local economic benefits are considerably less than forgone returns from agricultural activities if the forest were to be converted to the best agricultural uses. Arguably, continued protection of this forest is justified on the basis of the unknown value of its rich biodiversity and capacity to sequester CO2. Empirical findings show that the existing forest management system was less effective due to resource constraints and institutional weaknesses. Our study provides insights for the need to manage this forest for multiple uses. We recommend an integrated management strategy that balances local resource needs with biodiversity conservation. We suggest that improved stakeholder collaboration can facilitate sustainable management of this forest resource. Besides, carefully crafted payment for ecosystem services mechanisms and broad environmental education programs can support sustainable forest conservation for this and other similar forest ecosystems in Africa.

Experimental tests of tropical forest conservation measures

We conducted framed field experiments (FFEs) with local forest users in Tanzania. The harvest decisions are well below the individually optimal ones, suggesting significant non-pecuniary motivations. The participants display more pro-social behaviour than similar studies have shown, indicating that the forest specific framing influences participants’ behaviour. We tested three different conservation treatments: command and control (CAC), payment for environmental services (PES) and community forest management (CFM). CFM is as efficient as CAC in increasing pro-social forest use, despite not directly affecting the pecuniary gain. PES – as designed here – is the least effective treatment, but the results might be parameter sensitive. Women use forests more intensively than men, but are also more responsive to the treatments. The behavioural validity of the experiment is supported by strong correlation between behaviour in the experiment and in stated real life, while treatment validity cannot be tested directly. FFEs should become a supplement to traditional impact assessments (IA) of conservation policies, as it avoids many challenges that traditional IA methods face.

Reconciling timber extraction with biodiversity conservation in tropical forests using reduced-impact logging.

Summary Over 20% of the world's tropical forests have been selectively logged, and large expanses are allocated for future timber extraction. Reduced‐impact logging (RIL) is being promoted as best practice forestry that increases sustainability and lowers CO 2 emissions from logging, by reducing collateral damage associated with timber extraction. RIL is also expected to minimize the impacts of selective logging on biodiversity, although this is yet to be thoroughly tested.We undertake the most comprehensive study to date to investigate the biodiversity impacts of RIL across multiple taxonomic groups. We quantified birds, bats and large mammal assemblage structures, using a before‐after control‐impact (BACI) design across 20 sample sites over a 5‐year period. Faunal surveys utilized point counts, mist nets and line transects and yielded >250 species. We examined assemblage responses to logging, as well as partitions of feeding guild and strata (understorey vs. canopy), and then tested for relationships with logging intensity to assess the primary determinants of community composition.Community analysis revealed little effect of RIL on overall assemblages, as structure and composition were similar before and after logging, and between logging and control sites. Variation in bird assemblages was explained by natural rates of change over time, and not logging intensity. However, when partitioned by feeding guild and strata, the frugivorous and canopy bird ensembles changed as a result of RIL, although the latter was also associated with change over time. Bats exhibited variable changes post‐logging that were not related to logging, whereas large mammals showed no change at all.Indicator species analysis and correlations with logging intensities revealed that some species exhibited idiosyncratic responses to RIL, whilst abundance change of most others was associated with time. Synthesis and applications. Our study demonstrates the relatively benign effect of reduced‐impact logging (RIL) on birds, bats and large mammals in a neotropical forest context, and therefore, we propose that forest managers should improve timber extraction techniques more widely. If RIL is extensively adopted, forestry concessions could represent sizeable and important additions to the global conservation estate – over 4 million km2.

Advancing reference emission levels in subnational and national REDD+ initiatives: a CLASlite approach.

Conservation and monitoring of tropical forests requires accurate information on their extent and change dynamics. Cloud cover, sensor errors and technical barriers associated with satellite remote sensing data continue to prevent many national and sub-national REDD+ initiatives from developing their reference deforestation and forest degradation emission levels. Here we present a framework for large-scale historical forest cover change analysis using free multispectral satellite imagery in an extremely cloudy tropical forest region. The CLASlite approach provided highly automated mapping of tropical forest cover, deforestation and degradation from Landsat satellite imagery. Critically, the fractional cover of forest photosynthetic vegetation, non-photosynthetic vegetation, and bare substrates calculated by CLASlite provided scene-invariant quantities for forest cover, allowing for systematic mosaicking of incomplete satellite data coverage. A synthesized satellite-based data set of forest cover was thereby created, reducing image incompleteness caused by clouds, shadows or sensor errors. This approach can readily be implemented by single operators with highly constrained budgets. We test this framework on tropical forests of the Colombian Pacific Coast (Chocó) – one of the cloudiest regions on Earth, with successful comparison to the Colombian government’s deforestation map and a global deforestation map.

DIVERSIDAD DE ÁRBOLES Y ARBUSTOS EN FRAGMENTOS DE BOSQUE SECO TROPICAL EN RÍO HATO, PANAMÁ

The floristic composition of trees and shrubs in tropical dry forest fragments in Rio Hato, Panama was studied. We established 61 plots of 100 m 2 distributed randomly, totaling 0.61 hectares. In each sampling unit we measured all individuals above 5.0 cm DAP. We found a total of 52 tree species represented in 25 families, of which Fabaceae, Burseraceae, Myrtaceae and Rubiaceae account for 35% of the species. The species Sloanea terniflora was found in more than 60.6% of the quadrants. This species also proved to be the one with the highest relative dominance (23%) followed by Anacardium excelsum , with only 15 individuals of large diameters, showing a relative dominance of 10%. Mean diversity indices revealed intermediate values (Shannon index 3.13). While the number of tree species is relatively low when compared to other tropical dry forests in the region, the fragments in Rio Hato preserve floristic elements of ecological importance for the conservation of tropical dry forests. Garcinia madruno , the most abundant species is a key species in fruit production for wildlife and other species have been overexploited as timber resources, e.g. , Manilkara sapota and Copaifera aromatica . Establishing conservation strategies to safeguard these fragments as a source of tropical dry forest species and as wildlife refuges should be a priority for Panama.