Sun Coffee Plantations Research Articles

Seasonality modulates habitat cover effects on avian cross‐boundary responses and spillover

Species cross‐boundary response is a key mechanism affecting species spillover into agricultural fields. However, temporal changes in edge permeability, which may depend on the seasonal availability of resources in both matrix and native habitats, remain poorly understood. Here we tested how edge crossing behavior and the associated spillover of birds into sun coffee plantations respond to landscape structure and seasonality. We monitored the movement of six insectivorous understory bird species (four forest specialists and two forest generalists) using an automated telemetry system along a gradient of forest cover (7–60%) during two seasons (dry versus wet) at nine sampling sites at the Brazilian Atlantic forest. We monitored 116 individuals and obtained a total of 15 129 bird detections across seasons. Bird resistance to crossing edges was strongly driven by an interaction between seasonality and forest cover in the surrounding landscape, with higher resistance to crossing edges along the dry season and in landscapes with lower amount of forest cover. Furthermore, spillover patterns in plantations were driven by an interaction between forest cover and distance from forest edges, but this was most pronounced for forest‐specialist bird species. Forest specialists moved more intensively and farther from edges in more forested landscapes, whereas forest generalists showed similar patterns of occupation regardless of forest cover and isolation. Our study contributes to a better understanding of avian cross‐boundary responses and spillover in response to landscape structure across seasons, and the factors driving bird movement decisions in anthropogenic landscapes. There are a myriad of possible mechanisms governing movement decisions, and these mechanisms may interact in complex ways and remain important foci for research within the fields of tropical ecology and evolution.

Avian cross-habitat spillover as a bidirectional process modulated by matrix type, forest cover and fragment size

Cross-habitat spillover (i.e. the movement of individuals between different habitat types) occurs very often in agricultural landscapes, following temporary crop resource pulses that work as complementary resources for biodiversity. We tested how avian spillover at edges of forest fragments is affected by the adjacent agricultural matrix contrast (sun coffee plantations or pastures), forest fragment size, and forest cover at the landscape scale. We performed paired mist netting at forest edges (forest/sun coffee plantations and forest/pastures; N = 24) and estimated the spillover ratio and the dissimilarity of birds moving in- and out- forest fragments. We found that avian spillover in highly fragmented landscapes is a bidirectional process regardless of species habitat association or feeding guild. Matrix type is a key driver of spillover, and most spillover occurred when the matrix is of less contrast (i.e. sun coffee plantations). Spillover ratio at coffee interfaces increased with forest cover and also with fragment size, meanwhile at pasture interfaces spillover only increased at high values of forest cover and fragment size. Finally, we found that the dissimilarity between bird species entering and leaving the fragments was higher in pasture matrices, while at coffee interfaces the dissimilarity was lower. Landscape management aimed at reducing the contrast between matrix and habitat, increasing habitat cover and maintaining large fragments can intensify spillover movements across natural and anthropogenic habitats, and potentially, promote more ecosystem service provision by those species that are performing spillover movements.

Decrease in β‐diversity, but not in α‐diversity, of ants in intensively managed coffee plantations

Abstract Local land‐use intensity and surrounding landscape complexity affect the diversity of local species. Ants are an important biocontrol agent of the coffee berry borer (CBB), the main coffee pest worldwide. Although intensification of coffee production and deforestation in the surrounding landscape may reduce ant diversity, α‐ and β‐diversity patterns of ants in coffee landscapes remain poorly understood. Ants foraging in coffee bushes were sampled, using tuna baits along an agricultural intensification gradient (forest, shaded coffee and sun coffee) in a Neotropical coffee landscape. We evaluated the differences in α and β components of ant richness, community differentiation and habitat specificity of ant communities, in response to land‐use type and the percentage of surrounding forest. We found that ant β‐diversity and community differentiation among plots were significantly reduced with coffee management intensity. The amount of forest border adjacent to coffee plantations did not affect α‐ or β‐diversity. Yet, ant habitat specificity in the forest increased with plots having greater amounts of forest border, although in sun coffee plantations, the opposite was found: plots with greater forest border decreased habitat specificity. We found that conserving forest at landscape scales enhanced β‐diversity, community differentiation and habitat specificity of ants in the forest. Loss of forest cover at landscape scales (i.e. predominance of sun coffee) may lead to biotic homogenisation of ant communities. In conclusion, landscape‐wide ant richness is important in terms of biological CBB control by conservation.

Forest cover enhances natural enemy diversity and biological control services in Brazilian sun coffee plantations

Landscape structure and crop management directly affect insect communities, which can influence agriculturally relevant ecosystem services and disservices. However, little is known about the effect of landscape structure and local factors on pests, natural enemies, and biological control services in the Neotropics. We investigated how environmental conditions at local and landscape levels affect Leucoptera coffeella (insect pest), social wasps (natural enemies), and the provision of biological control services in 16 Brazilian coffee plantations under different crop management and landscape contexts. We considered microclimatic conditions, coffee plantation size, and management intensity at the local level; and forest cover, landscape diversity, and edge density at the landscape level. Pest population, wasp communities, and biocontrol services were monitored in wet and dry seasons when L. coffeella outbreaks occur. We found that the amount of forest in the surrounding landscape was more important for explaining patterns than the local environment, landscape diversity, or landscape configuration. In both seasons, L. coffeella was negatively affected by forest cover, whereas biological control and richness and abundance of social wasps increased with increasing forest cover at multiple spatial scales. Moreover, biological control was positively correlated with wasp abundance during pest outbreaks, suggesting that social wasps are important natural enemies and provide pest control services within coffee plantations. We provide the first empirical evidence that forest cover is important for the maintenance of social wasp diversity and associated pest control services in a Brazilian coffee-producing region.

The potential protective value of ants in Northern Australian coffee plantations

Native ants are the oldest example of biological control agents used in tropical tree crops. Unfortunately, intensification of agricultural practices has led to a simplification of habitat and subsequent loss of native ant biodiversity. This article describes research that evaluated the native and introduced ants present in the canopies of two Australian sun coffee plantations, their distribution pattern and their potential to limit pests. The presence in coffee plantations of a range of beneficial insects and parasites, plus the effect of ants, most notably Iridomyrmex suchieri Forel, may maintain potential pests at low levels in coffee plantations. These effects may be important for future biological control programs of coffee pests in Australia, although the sun coffee grown here does not harbor a large variety of canopy ant species.

Long-term declines in bird populations in tropical agricultural countryside

Tropical agriculture is a major driver of biodiversity loss, yet it can provide conservation opportunities, especially where protected areas are inadequate. To investigate the long-term biodiversity capacity of agricultural countryside, we quantified bird population trends in Costa Rica by mist netting 57,255 birds of 265 species between 1999 and 2010 in sun coffee plantations, riparian corridors, secondary forests, forest fragments, and primary forest reserves. More bird populations (69) were declining than were stable (39) or increasing (4). Declines were common in resident, insectivorous, and more specialized species. There was no relationship between the species richness of a habitat and its conservation value. High-value forest bird communities were characterized by their distinct species composition and habitat and dietary functional signatures. While 49% of bird species preferred forest to coffee, 39% preferred coffee to forest and 12% used both habitats, indicating that coffee plantations have some conservation value. Coffee plantations, although lacking most of the forest specialists, hosted 185 bird species, had the highest capture rates, and supported increasing numbers of some forest species. Coffee plantations with higher tree cover (7% vs. 13%) had more species with increasing capture rates, twice as many forest specialists, and half as many nonforest species. Costa Rican countryside habitats, especially those with greater tree cover, host many bird species and are critical for connecting bird populations in forest remnants. Diversified agricultural landscapes can enhance the biodiversity capacity of tropical countryside, but, for the long-term persistence of all forest bird species, large (>1,000 ha) protected areas are essential.

Biodiversity extinction thresholds are modulated by matrix type

Biodiversity extinction thresholds are abrupt declines in biological diversity that occur with habitat loss, associated with a decline in habitat connectivity. Matrix quality should influence the location of thresholds along habitat loss gradients through its effects on connectivity; however these relationships have seldom been explored empirically. Using field data from 23 independent 1254 ha landscapes in the Brazilian Atlantic Forest, we evaluated how tropical avian biodiversity responds to native forest loss within habitat patches embedded either in homogeneous pasture matrix context (with a high proportion of cattle pastures), and heterogeneous coffee matrix context (with high abundance of sun coffee plantations). We considered taxonomic, functional, and phylogenetic diversity, and tested if matrix type and choice of diversity metric influenced the location of biodiversity thresholds along the forest cover gradient. We found that matrix type postponed the abrupt loss of taxonomic diversity, from a threshold of 35% of forest cover in homogeneous pasture matrix to 19% in heterogeneous coffee matrix. Phylogenetic diversity responded similarly, with thresholds at 30 and 24% in homogeneous‐pasture and heterogeneous‐coffee matrices, respectively, but no relationship with forest cover was detected when corrected for richness correlation. Despite the absence of a threshold for functional diversity in either matrix types, a strong decline below 20% of habitat amount was detected. Finally, below 20% native habitat loss, all diversity indices demonstrated abrupt declines, indicating that even higher‐quality matrices cannot postpone diversity loss below this critical threshold. These results highlight that taxonomic diversity is a more sensitive index of biodiversity loss in fragmented landscapes, which may be used as a benchmark to prevent subsequent functional and phylogenetic losses. Furthermore, increasing matrix quality appears an efficient conservation strategy to maintain higher biodiversity levels in fragmented landscapes over a larger range of habitat loss.

Bird community response to landscape and foliage arthropod variables in sun coffee of central Kenyan highlands

Land conversion represents a serious threat to terrestrial biodiversity and effective conservation in human-dominated landscapes requires an understanding of the relationship between spatial heterogeneity and biodiversity. Coffee is the most valuable tropical export in the world with the capacity to affect biodiversity on a large scale, and much of the world's coffee is grown in open plantations (sun coffee), where little research has documented how landscape structure or food availability affect bird diversity. We examined the effects of both landscape characteristics and foliage arthropod abundance on bird species richness, total bird abundance and the abundance of foraging guilds in sun coffee plantations of central Kenyan highlands. Variation in the local landscape appeared to have little effect on bird abundance, while the foliage arthropod community, particularly number of arthropod orders, may have a strong impact on omnivore and insectivore abundance in sun coffee. These results do not mean small scale fragments or landscape composition is unimportant to bird communities in our region for several reasons, including the high model uncertainty that may indicate an important missing variable, the habitat complexity and presence of large forest reserves around our study sites, and the single scale at which our variables were tested. Our results indicate that farm managers wanting to increase bird abundance, especially omnivores and insectivores, should consider balancing the need to eradicate coffee pests and leaving an intact arthropod community that likely increases these guilds. Further study is needed to validate these patterns, which may have strong implications for bird biodiversity in agricultural settings across other areas in eastern Africa.

Effects of bird and bat exclusion on coffee pest control at multiple spatial scales

Despite the key role of biological control in agricultural landscapes, we still poorly understand how landscape structure modulates pest control at different spatial scales. Here we take an experimental approach to explore whether bird and bat exclusion affects pest control in sun coffee plantations, and whether this service is consistent at different spatial scales. We experimentally excluded flying vertebrates from coffee plants in 32 sites in the Brazilian Atlantic Forest, encompassing a gradient of forest cover at landscape (2 km radius) and local (300 m) spatial scales, and quantified coffee leaf loss, as an indicator of herbivory, and fruit set. Leaf loss decreased with higher landscape forest cover, but this relation was significantly different between treatment and control plants depending on local forest cover. On the other hand, fruit set responded to the interaction between treatment and local forest cover but was not affected by landscape forest cover. More specifically, fruit set increased significantly with local forest cover in exclusion treatments and showed a non-significant decrease in open controls. These results suggest that services provided by flying vertebrates are modulated by processes occurring at different spatial scales. We posit that in areas with high local forest cover flying vertebrates may establish negative interactions with predaceous arthropods (i.e. intraguild predation), but this would not be the case in areas with low local forest cover. We highlight the importance of employing a multi-scale analysis in systems where multiple species, which perceive the landscape differently, are providing ecosystem services.

Landscape structure influences bee community and coffee pollination at different spatial scales

Although several studies have shown that the presence of bees results in increased crop yields, the mechanisms that determine pollination service across different spatial scales are still largely unknown. Here, we evaluated the influence of landscape structure over bee community composition and coffee (Coffea arabica) pollination. Our study was undertaken in one of the most important coffee-producing regions of Brazil, and comprised nine landscapes of sun coffee plantations surrounded by different amounts of Atlantic Forest remnants. Using floral exclusion experiments we evaluated fruit set in 15 coffee shrubs per landscape. We also sampled the bees visiting coffee flowers. Our analyses were made at two landscape scales, with 1 and 2km radii, and one shrub scale, with 300m radius around each coffee shrub. We collected 241 bee individuals and identified a total of 22 species. The honeybee Apis mellifera (Apini) was the most abundant flower visitor followed by Trigona spinipes (Meliponini). Native bee abundance, richness and diversity were positively affected by forest cover at the shrub scale. Honeybee abundance, on the other hand, was negatively affected by forest cover at the shrub scale. The presence of bees resulted in an increase in coffee fruit set of 28%. A. mellifera abundance positively affected fruit set across spatial scales, while the composition of the native bee community affected fruit set differently at the landscape scales than at the shrub scale. Our work shows that bee pollination services are affected by landscape structure at different spatial scales. These findings can be used in conservation and agricultural planning to maximize crop production while safeguarding biodiversity and the provision of pollination services.

Adaptación a la variabilidad climática entre los caficultores de las cuencas de los ríos Porce y Chinchiná, Colombia

This article seeks to explain the practices used by small farmers to cope with climate variability and extreme weather events in the basins of the Chinchiná and Porce rivers located on the central Andes in Colombia. The information wasglacie collected through interviews, observations on farms and workshops with farmers. Additionally historical averages on temperature, precipitation and sunshine were compared with those values recorded in 2010 during the transition between El Niño an La Niña events. During the first quarter of 2010 the average temperature in Chinchiná increased by 1.4 C° and the solar brightness by 14%, while the precipitation experienced a 46% reduction. In contrast, during the second half of the year there was a decrease of 0.8 C° in temperature, a 31% reduction in solar brightness and an increase in precipitation of 62%. The coffee production in the years 2011 and 2012 was the lowest in the country in the last 35 years despite the cultivated area increased. These changes affected the coffee plantations and substantially decreased grain coffe production. Coffee production in the years 2011 and 2012 was the lowest in the country in the last 35 years despite the cultivated area increase. These fall in coffee production was also a result of the renewal with rust resistant varieties, which at that time had not yet begun to produce. Most of the farmers have 5 hectares or less and are union members in the National Federation of Coffee Growers of Colombia (fncc), which provides multiple services to them including an extension service with spread of the findings of field investigations carried out by the National Coffee Research Center (cenicafe). These study results indicates some strategies used by peasants to minimize the effects of climate variability: the shade management in coffee plantations, especially with banana (Musa sp.) and guamo (Inga sp); their renewal with the rust resistant variety named Castillo; the association of crops, particularly coffee, maize and bean; the use of mulches, organic fertilizers and mycorrhizae; a proper fertilization; the cultivation of two-axis coffee plants; the staggered planting of coffee in different plots and the reforestation of hillsides and births water, especially with (Guadua angustifolia), are strategies used to minimize the effects of climate variability. However these strategies are more frequent in Porce than in Chinchiná where sun coffee plantations and intensive agriculture are predominants. The article indicates that adaptation to climate variability is not achieved only by technological measures if do not decrease the sources of vulnerability of the rural population. The farmers are more exposed to the effects of weather because of their poverty, as a result of building on steep slopes, by cause of the volatility in the international price of coffee, by virtue of the exchange rate, due to the lack of a culture of crop insurance and for the lack of generational renewal in agriculture. Additionally peasants in Chinchiná faced threats of earthquakes, eruption of Nevado del Ruiz volcano, susceptibility of volcanic soils to mass removals and glacier melting, an increasingly process accelerated by climate change. This paper also highlights the social, economic and political adaptation strategies to climate variability. We found that the resilience of rural households increases when resorting to agrotourism, integration of family labor, associations, political mobilization for claiming benefits, casual wage labor on other farms, integration to fair markets coffee and coffee certifications that increase the price of This work also highlights the social, economic and political adaptation strategies to climate variability. We found that the resilience of rural households increases when resorting to the agrotourism, integration of family labor, the union associations, political mobilization for claiming benefits, the casual wage labor on other farms, the integration to fair markets of coffee and coffee certifications that increase the price of grain of coffee grain. Not all spontaneous adaptation measures are positive, it is necessary to evaluate the experience of many coffee farms of medium length that were converted to livestock, rural tourism and citrus growing. Since climate change and climate variability has increased the frequency and intensity of extreme weather events, this work also helps to identify vulnerabilities and adaptation of rural populations to climate change and extreme events.

Countryside biogeography of Neotropical reptiles and amphibians.

The future of biodiversity and ecosystem services depends largely on the capacity of human-dominated ecosystems to support them, yet this capacity remains largely unknown. Using the framework of countryside biogeography, and working in the Las Cruces system of Coto Brus, Costa Rica, we assessed reptile and amphibian assemblages within four habitats that typify much of the Neotropics: sun coffee plantations (12 sites), pasture (12 sites), remnant forest elements (12 sites), and a larger, contiguous protected forest (3 sites in one forest). Through analysis of 1678 captures of 67 species, we draw four primary conclusions. First, we found that the majority of reptile (60%) and amphibian (70%) species in this study used an array of habitat types, including coffee plantations and actively grazed pastures. Second, we found that coffee plantations and pastures hosted rich, albeit different and less dense, reptile and amphibian biodiversity relative to the 326-ha Las Cruces Forest Reserve and neighboring forest elements. Third, we found that the small ribbons of "countryside forest elements" weaving through farmland collectively increased the effective size of a 326-ha local forest reserve 16-fold for reptiles and 14-fold for amphibians within our 236-km2 study area. Therefore, countryside forest elements, often too small for most remote sensing techniques to identify, are contributing -95% of the available habitat for forest-dependent reptiles and amphibians in our largely human-dominated study region. Fourth, we found large and pond-reproducing amphibians to prefer human-made habitats, whereas small, stream-reproducing, and directly developing species are more dependent on forest elements. Our investigation demonstrates that tropical farming landscapes can support substantial reptile and amphibian biodiversity. Our approach provides a framework for estimating the conservation value of the complex working landscapes that constitute roughly half of the global land surface, and which are experiencing intensification pressure worldwide.

Complementary ecosystem services provided by pest predators and pollinators increase quantity and quality of coffee yields

Wild animals substantially support crop production by providing ecosystem services, such as pollination and natural pest control. However, the strengths of synergies between ecosystem services and their dependencies on land-use management are largely unknown. Here, we took an experimental approach to test the impact of land-use intensification on both individual and combined pollination and pest control services in coffee production systems at Mount Kilimanjaro. We established a full-factorial pollinator and vertebrate exclosure experiment along a land-use gradient from traditional homegardens (agroforestry systems), shaded coffee plantations to sun coffee plantations (total sample size = 180 coffee bushes). The exclusion of vertebrates led to a reduction in fruit set of ca 9%. Pollinators did not affect fruit set, but significantly increased fruit weight of coffee by an average of 7.4%. We found no significant decline of these ecosystem services along the land-use gradient. Pest control and pollination service were thus complementary, contributing to coffee production by affecting the quantity and quality of a major tropical cash crop across different coffee production systems at Mount Kilimanjaro.

Effect of Two Agroecological Management Strategies on Ant (Hymenoptera: Formicidae) Diversity on Coffee Plantations in Southwestern Colombia

Simplification of agroecosystems because of industrialization of agriculture may cause the loss of associated animal biodiversity of both vertebrates and invertebrates. To measure how the agricultural intensification on coffee plantations affects ant biodiversity, we intensively sampled ants in Caldono (Cauca, Colombia). We surveyed 15 sites classified into three management types: sun coffee plantations, shaded coffee plantations, and forest patches. Fifteen 50-m linear transects, each one consisting of 5 pitfall traps and 5 tuna baits, were set at each sampling location between December of 2009 and February of 2010. We collected 18,186 ants that represent 82 ant species, 34 genera, and 9 subfamilies of Formicidae (Hymenoptera: Formicidae). The management intensification index showed an increasing intensification gradient along the 15 sampling locations from forest patches to shaded coffee to sun coffee plantations. Shaded coffee plantations harbored the highest number of species (60), followed by forest (56) and sun coffee (33). Ant species composition and plant structure on shaded coffee plantations resembled the forest patches more than the sun coffee plantations. Forest and shaded coffee plantations had a more equitable distribution of ant species, whereas in sun coffee plantations, Linepithema neotropicum (Emery) and Ectatomma ruidum (Roger) typically outnumbered all other ant species. Evidence from functional groups indicated that specific habitat and feeding requirements exist among the species that are found together. Our results confirmed that intensification of agriculture negatively affects ant diversity, despite the fact that farms were located in a heterogeneous landscape, suggesting that agroecological management is a strong determinant in the conservation of wild fauna.

Acarofauna associated with coffee shrubs in relation to the distance of forest fragments

The conversion of natural habitats into agriculture ones and the simplification of the structure of landscapes are the main causes of the global loss of biodiversity. Agroecosystems, especially monocultures, normally provide food resources and benefit organisms only when surrounded by forests. Mites (Arachnida: Acari) are one of the most diverse groups of arthropods and contribute to the function of ecosystems and agroecosystems. We aimed at determining the response of the coffee mite community to the distance from adjacent forest fragments. We evaluated leaves of coffee shrubs which were naturally found in the interior (0 m) and edge (25 m) of the fragments and in full sun coffee plantations located at 50 and 100 m in relation to the interior of the fragments. Although there was no pattern of reduction of mite abundance in relation to the distance from the centre of the forest fragments according with linear regressions, faunistic analyses revealed that abundance, dominance and frequency levels for some mite families were influenced by the distance from the centre of the forest fragments.

Shade-grown coffee in Puerto Rico: Opportunities to preserve biodiversity while reinvigorating a struggling agricultural commodity

Shade-grown coffee contributes to biodiversity conservation and has many ecological benefits. We reviewed historical trends in coffee production and interviewed 100 coffee growers in 1999 to determine current management practices and attitudes toward the cultivation of sun and shade coffee in Puerto Rico. We discuss the outlook for the coffee industry in the 21st century and implications for biodiversity conservation, hoping lessons from Puerto Rico will apply to the international coffee industry. Throughout the 20th century, government intervention, including subsidies and technical assistance, supported coffee farming in Puerto Rico. In an effort to modernize coffee production and increase yields, the conversion from shade to sun coffee plantations was encouraged. Despite government support, the amount of land devoted to this once dominant agricultural commodity declined markedly between 1982 and 2007 (84%), due to labor shortages, low income, and catastrophic hurricanes. We found that a return to shaded plantations would be embraced by most farmers. Growers of shaded coffee were generally happier with their cultivation practices (89.3% satisfied) than growers of sun coffee (60.9% satisfied), valued biodiversity, and were willing to cultivate coffee under shade if given similar incentives to those received for farming sun coffee. The future of the coffee industry in Puerto Rico may depend on government programs that capitalize upon emerging markets for sustainably produced, shade-grown coffee. We conclude that where governments have close ties to the coffee industry, they should strive to wed economic development with the conservation of biodiversity and associated ecological services by providing support and incentives for the production of shade coffee.

Testing ant predation on the coffee berry borer in shaded and sun coffee plantations in Colombia

AbstractSoil‐dwelling ants, many of which are generalist predators, are more diverse in shaded than in sun coffee plantations without trees. We compared ant predation on the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae) in three shaded and three sun coffee plantations in Apía, Colombia, in both the wet and the dry seasons. We found that H. hampei adults exposed to ants for 5 days suffered higher removal in shaded plantations and in the wet season. In the laboratory, we observed that ants killed 74–99% of H. hampei adults over the course of 5 days. Ants appear to be important predators of H. hampei, particularly in shaded coffee plantations and in the wet season.

Ecological Role of a Tree (Gmelina Arborea) Plantation in Guatemala: An Assessment of an Alternative Land use for Tropical Avian Conservation

AbstractEstablished parks and nature reserves may be inadequate to preserve long-term biotic diversity, especially in tropical regions of Latin America where anthropogenic disturbance and land-conversion is an ongoing problem. Demand for economically productive land uses, such as cattle pastures or monoculture plantations, is one of the greatest threats to habitat and wildlife preservation. As a result, conservation biologists have turned to examining attributes of nonprotected lands to determine which land uses both support wildlife and make economic sense. I examined bird use of a plantation of Gmelina arborea (“white teak” or “melina” trees; hereafter “plantation”) in Guatemala to assess its suitability as bird habitat. Gmelina arborea is grown mainly for wood and paper pulp. Several compositionally different habitats were identified, based on the amount of natural vegetation grown within and among the plantation trees, forming a heterogeneous landscape. I detected 195 bird species from 45 families within this plantation-dominated landscape, and 144 species in plantation habitats combined. I observed a positive association between increased vegetative complexity and bird species richness; moreover, bird species richness attained levels statistically indistinguishable from those found in nearby forest fragments. Mixed plantation habitat containing 19–31% natural vegetative coverage supported bird communities that equaled or surpassed levels of species richness found by other researchers in shaded coffee (Coffea spp.) plantations. However, pure stands of G. arborea supported richness levels equal to those of grazed pasture; diversity levels associated with both these land uses were close to those reported for sun coffee plantations. Clearly, native vegetation played a significant role in enhancing bird species richness in the plantation habitat, and amounts of relative cover similar to or exceeding those in the plantation I studied should be considered in any management plan for G. arborea in Central America.Rol Ecológico de Plantaciones de Árboles de Gmelina arborea en Guatemala: Una Evaluación de un Uso Alternativo del Suelo para la Conservación de las Aves Tropicales

Nesting bird species in sun coffee, pasture, and understory forest in southern Costa Rica

We investigated avian nest distribution and success in understoryforest, sun coffee plantations, and pasture in southern Costa Rica. Nestsearching occurred in plantations and forest in 1999 and 2000 and in pastures in2000. Nests were monitored until they failed or fledged young. Antbirds(Thamnophilidae) were the most common understory forest nesters and were notfound nesting in the plantations or pastures. Common nesting species in theplantations included Turdidae, Tyrannidae, Cardinalidae, and Thraupidae, many ofwhich are typical of forest edge/canopy or open, scrubby habitats. Two speciesassociated with forest interior, Henicorhina leucostictaand Buarremon brunneinucha, were found nesting in theplantations. Pastures supported similar types of nesting species as theplantations, with the exception of the forest-interior species. Daily mortalityrates (DMRs) for above-ground cup-nesting species in plantations and pastureswere similar to those for species nesting in forest at our site and a site inPanama. The results indicate that conversion from forest to pastures and suncoffee plantations diminishes nesting habitat for forest-interior species, whilenumerous forest edge/canopy species and open-country species are able to nest inthese agricultural land-cover types. As a group, species nesting in theplantations and pastures do not have unusually high nest mortality rates,although species-specific studies are lacking. Nesting species distributionsacross habitat types and DMRs at our study site may be influenced by the largeamount of forest in the landscape.

Forest regeneration in abandoned coffee plantations and pastures in the Cordillera Central of Puerto Rico

Forest structure and species composition were described in abandonedshade and sun coffee plantations and abandoned pastures in Puerto Rico. Foreststructural characteristics were similar to older forest sites afterapproximately 30 yr of recovery. The historical presence of shadecoffee plantations as the dominant agricultural activity in the region hasresulted in the homogenization of secondary forest composition. The continuousdominance of Coffea arabica and species used for shade inabandoned shade coffee contributed to a slower rate of species compositionchange in comparison to abandoned pastures. Abandoned pastures were initiallycolonized by a group of light demanding and/or wind dispersed species and thenby shade tolerant species characteristic of abandoned shade coffee plantations,suggesting that the secondary forests of abandoned shade coffee plantation arethe major source of species in this landscape. The presence of a few isolatedbig trees in sun coffee plantations appeared to facilitate colonization ofwoodyspecies similar in composition to abandoned shade coffee plantations. In amultivariate analysis, time since abandonment and elevation were the variablesthat explained the majority of variability in species composition among sites.However, a few native species (e.g. Guarea guidonia,Casearia sylvestris, Ocotealeucoxylon) were common regardless of land use history or elevation.In contrast, important old forest species (e.g. Sloaneaberteriana, Dacryodes excelsa,Manilkara bidentata) were rare or absent from most of thesecondary forest stands suggesting the need to reintroduce these species. Landmanagement and conservation efforts can be improved by incorporating theeffectsof land use history on secondary forest dynamics.