TRI Fellows Research Projects, 2005

Yale Tropical Resources Institute

Dr. Lisa M. Curran, Director
Dr. Amity Doolittle, Program Director

School of Forestry & Environmental Studies
210 Prospect Street
New Haven, CT 06511
U.S.A.

phone 203.432.3660
fax 203.436.4404

www.yale.edu/tri

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TRI Fellows Research Projects, 2005

Africa
Asia

Australia

Central America
South America

Central America

Lisa Bassani	Dan Braden	Dylan Craven
Wendy Francesconi	Taek Joo Kim	Hugo Lam
Alexander Shenkin	Kristen Welsh	Larissa Yocom

Lisa Bassani

U.S. Tropical Forest Conservation Act: Politics of Participation and Implications for Conservation ‘Success’

As budgets for conservation in the developing world continue to decline, many of these nations are seeking alternative means by which they can finance conservation efforts. One such strategy, called debt-for-nature swaps, provides debt-relief for developing nations in exchange for payments made by the beneficiary government for targeted conservation efforts. The US Tropical Conservation Act of 1998, which provides funding for such swaps, places important conditions on these agreements. Under the TFCA legislation, funds must be administered by a local NGO and there must be broad participation in the management and oversight of those funds. To accomplish the latter, TFCA mandates the inclusion of international and local NGOs, representatives from the US and beneficiary government, scientists and researchers in a formal Oversight Committee.

The Upper Chagres watershed, pictured above, contains Panama's most important water resources and will receive protection from one of Panama's debt-for-nature swaps.

Using two case studies of debt-for-nature swaps in Panama, my research explores the structure of these transactions and the effects of the legislative requirements on NGO-government relationships. I focus specifically on the response of state actors to the growing role of NGOs in conservation finance initiatives and its impacts on the implementation of the swaps on the ground. I accomplish this through an institutional ethnography of the actors involved in the swap’s Oversight Committee. Research methods involved a combination of participant observation in meetings, presentations, and workshops, semi-structured interviews with government and non-government actors, participation on projects involving Panama’s National Environment Authority, and numerous informal discussions with relevant actors.

Dan Braden

Physiological ecology of reforestation plantings across a rainfall gradient in Panama

There are several morphological and physiological pathways by which a tree can become a productive part of a forestry system. It can grow quickly in full-sun conditions in an effort to reach the canopy first (”shade intolerant“ strategy), or it can grow more slowly in the understory (”shade tolerant“ strategy). It can optimize its growth strategy to the specifications of a particular site (?site-restricted? strategy), or it can be a generalist capable of growing anywhere. Cultivating productive forestry systems requires not only an understanding of how to balance these different strategies, but also of how variable these traits are across and within species when plants are presented with different growing conditions – that is, their degree of plasticity.

This is particularly important when selecting species to plant, and management systems to adopt, in the ?full-sun? conditions of a reforestation system. The Native Species Reforestation Project (PRORENA) provides a large-scale opportunity to investigate the plasticity of a range of species growing under full sun, across a rainfall gradient. We investigated the degrees of plasticity shown by 24 species planted in 2003, categorizing them as a) shade intolerant, b) shade tolerant, c) site-restricted, d) generalist, e) native, and f) non-native. All species were planted in homogenous blocks under open sun conditions in wet (3 m of rain per year), semi-wet (2.4 m of rain per year) and dry (1.8 m of rain per year) abandoned pasture land.

Morphological and physiological measurements included photosynthetic rate, stomatal conductance, wet weight, specific leaf area, water use efficiency and leaf nutrient content. The methodology developed for this study is expected to be used on subsequent PRORENA plantings, including monocultures of 50 additional species and, ultimately, polycultures. This information will not only provide important baseline information for comparison as the stands develop, but will also allow assessment of the implications of leaf plasticity for species selection and management of reforestation efforts in dry, semi-dry, and wet tropical environments.

Dylan Craven

Variation of Understory Light Regimes of Native Tree Species Plantings along a Rainfall Gradient in Panama

To rehabilitate the degraded lands created by the deforestation of tropical forests, effective reforestation strategies must be developed. Native species plantations must overcome physical and biological barriers, such as soil compaction, low soil fertility, and absence of seed sources, to enable secondary forests to regenerate in these areas. In response to the biological stresses created by extant site conditions, tree species adapt both their morphology and architecture in distinct ways via certain physiological processes.

Tree morphology and architecture – crown diameter, crown shape, crown density, branching and rooting patterns, leaf orientation to incident light, leaf shape and size – mediate micro-site conditions. Gradually, trees improve micro-site conditions by increasing soil fertility and structure, increasing soil moisture, and lowering both the quality and quantity of incident solar radiation. Improved micro-site conditions allow a wider variety of tree species to germinate their seeds and establish seedlings under the plantation canopy.

Dylan showing some journalists and STRI folk how he took the LAI measurements (using LiCor's LAI 2000 Canopy Analyzers).

In the study I performed this summer, I examined the understory light regimes of 22 native tree species at two sites (P.N. Soberanía and Río Hato) of differing precipitation levels in Panamá. I hypothesized that different species have distinct strategies with which they interact with site conditions, and that these differences could be captured via a related host of morphological and architectural measurements. To test these hypotheses, I measured morphological characteristics of these species – leaf area index (LAI), photosynthetically active photon flux density (PPFD), leaf angle (of 8 species), and specific leaf area (SLA). Through the MANOVA tests of variance that I will perform, I will determine whether significant differences exist between and among species’ physiological responses to contrasting amounts of precipitation. Tree species that have higher LAI values, transmit less PPFD, have leaf angles more perpendicular to incident solar radiation, and have higher SLA values will have a greater capacity to facilitate secondary forest succession by creating more favorable habitats for seed germination and seedling establishment.

The results of this study will aid efforts to reforest degraded lands by identifying which species ameliorate micro-site conditions most rapidly during the initial period of plantation establishment.

Wendy Francesconi

Bird Species Composition in Living Fences: Assessment of the effectiveness of living fences to connect the fragmented landscape in Esparza, Costa Rica.

My research focused on how the avian community was characterized in the living fences of silvopastoral farms. silvopastoral systems are agroforestry systems that combine livestock and tree production. Living fences are a type of silvopastoral system in which the planted trees serves as fences to divide the pastures for grazing purposes. This study was done to determine the effectiveness of living fences to conserve bird diversity by providing habitat between forest fragments. The study looked at the composition of species (generalist and specialist) that use living fences as refuge as they move across the fragmented landscape.

Simple Live Fence in the horizon. Picture taken in the district of San Jeronimo, Costa Rica.

The selected fences where classified into three different blocks: live fences that are connected to, moderately distant from and distant from secondary forest patches. The presence of birds was monitored using the Point Counts methodology in transects along the fence, and a total of 667 individuals of 75 species were observed. The study monitored live fence networks of five silvopastoral farms, and each fence was repeated four times. The study characterized the vegetative cover of the fences, as well as the remnant trees within the observation points. Tree diversity, crown diameter, diameter at base height (DBH), and tree and trunk heights were measured; variables were taken into account to perform correlations between bird species richness, live fence and remnant tree characterization.

According to the results obtained, distance to forest patches is not as significant as fence structure and composition for promoting greater bird diversity in living fences. In the context of live fences, greater tree diversity and vegetative cover contribute more to bird species richness of generalist and forest specialized species.

Taek Joo Kim

Rehabilitating Abandoned Pastures in Panama:
Control of the Invasive Exotic Grass, Saccharum spontaneum, through Shading

A highly vigorous grass, Saccharum spontaneum, has occupied abandoned agricultural lands in the Panama Canal Watershed for decades. This dominant grass grows very fast and prevents native tree species from resprouting. In spite of its harmful effects, few studies have been done on

Procedure of building shade clothes structure.

Saccharum growth. On behalf of the PRORENA, I spent three months this summer measuring the biomass of Saccharum spontaneum under different shading conditions. I established eight replicate sampling plots (four meters by 20 meters) in the canal region, formerly a military restricted area called the ACP (Autoridad del Canal de Panamà). In each plot I established five shade treatment subplots - 50%, 25%, 15%, 5~6%, and 0% (full sunlight). Throughout the rainy season, which lasts from August to January, I will take biomass measurements every month and a half and compare them. The results will show how Saccharum spontaneum acclimates to different shade conditions, information that will be used in developing a removal strategy for the grass.

Hugo Lam

Comparisons of growth and yield among five native and one exotic tree species at six sites in the western province of Chiriqui, Panama

Governments, NGOs, businesses, and local communities are becoming more interested in using native tree species for reforestation projects throughout Latin America, as farmers are discovering they are well suited for degraded soils. This is significant considering that deforestation destroys large areas of tropical forest, decreasing the number of native species that can provide high quality wood, sequester carbon, and supply non-timber forest products. The increasing demand for these services opens up an opportunity for businesses and local farmers interested in investing in native tree species for reforestation programs that could supplement national and international markets.

Futuro Forestal, a company capitalizing on this opportunity, uses native tree species for reforestation programs in Panama and is the first to market carbon credits in the country. Reforestation programs there began in 1992 with exotic and native species, and in 2001 PRORENA (Proyecto de Reforestacion con Especies Nativas) initiated reforestation projects with only native tree species at several sites. PRORENA and Futuro Forestal collaborate to manage a series of research plots of native species in the Western province of Chiriqui.

Futuro Forestal’s mixed plantation of Cedro Espino, Teca, Caoba, and Amarillo at Chiriqui province, Panama

Very little information is available on the growth and yield of native tree species as well on comparing growth between native and exotic tree species and between sites of similar elevation and climate but different soil types. This research will present data on growth and yield of five native and one exotic tree species, growing in different soil conditions that Futuro Forestal is using in its reforestation projects. I hypothesize that native tree species have higher growth and yield than exotic tree species, and that native tree species differentiate in growth and performance in relation to difference in soil types. This research will present silvicultural recommendations based on data on growth and yield of five natives and one exotic tree species growing on six different sites in the western province of Chiriqui, Panama.

Alexander Shenkin

Panama is a critical area for biodiversity conservation given its position as a tropical bottleneck between two continents which has lost much of its original forest cover. Reforestation efforts and selection trials are currently underway at a number of sites there and are showing remarkable variability in tree growth performance. While the growth of species in these sites will determine suitability and dictate planting choices, the reasons behind differing performance are largely unknown. It is generally assumed that differences in climate are responsible for this performance variability, but there are no studies that have examined this.

In order to understand the role soil plays in these differences, I am conducting a potted-tree bioassay. I took soil from two sites, placed them in the same climate and watering regimes, and planted seedlings of three species in them. By comparing the performance of plants in this study with the selection trials underway in the field, we will start to understand what effect soil has on growth. By growing these trees in sterilized soil, we can also start to understand the role of the biotic component of the soil.

In addition, I am examining the effect of forest-soil inoculation on tree performance as a possible cheap and easy method to increase tree performance. The results of this study will help plan for more effective reforestation efforts as well as contribute to the understanding of tropical forest ecology.

Kristen Welsh

Water Sustainability in a Costa Rican Biological Corridor:
Assessing Social and Physical Aspects within Local Communities

In the heart of the Path of the Tapir Biological Corridor in southwestern Costa Rica, many rural households lack municipal access to potable water. While in urban areas residents benefit from public water connections, rural communities are forced to devise their own mechanisms for water acquisition. Within this context, the objectives of this research were to evaluate where local people obtain their water, assess their dependence on local rivers and streams, and investigate the quality of these water bodies. I focused my study within the watersheds of the Baru River and the Guabo River and assessed three main components.

A view of the Guabo River

First, I collected data from governmental agencies dealing with water or environmental legislation in Costa Rica, in order to evaluate how watersheds in this region of the country were managed. The second component involved interviewing local residents to assess their water source, problems with their water supply, and what impacts they may have upon water quality. As a final component of the research, I conducted river sampling along the Baru and Guabo Rivers, as well as their two main tributaries, to assess the condition of these rivers.

The results of this study will be presented to the collaborator for this project, the Association of Friends of Nature of the Central and South Pacific of Costa Rica (ASANA), with the hope that they can utilize this information to initiate workshops to inform local people of the importance of water and its protection.

Larissa Yocom

Reforestation in the tropics: anatomy of native tree leaves across a climatic gradient

Humans are clearing forest in the tropics at a rapid pace, and in a way that can give rise to soil degradation, disruption of watershed services, and loss of biodiversity. To combat these problems, the Native Species Reforestation Project (PRORENA) in Panama is researching financially, socially, and ecologically sound ways to reestablish native forests on degraded landscapes. PRORENA has planted 75 tree species in experimental plots at several locations across Panama. My research seeks to determine how well 25 of these species, planted at three sites, are adapting to climatic and site differences, by looking at the anatomy of the leaves.

Measuring native species growth in Soberanía National Park, Panama

I collected nine leaf samples from each species at each site. Measurements I will be taking on the leaves include cuticle thickness, stomatal frequency and size, thickness of upper epidermis and palisade mesophyll, and number of palisade layers. I expect to find that some tree species are more anatomically adaptable and that this will correlate with high growth and survival rates across sites. This data on performance of different native species in different conditions may be useful for land managers throughout the tropical Americas as they attempt reforestation projects.

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