Search

Coffee is one of the most important tropical crops on earth, considering both its gross production value and the number of families that depend on it for their livelihoods. Coffee also grows within some of the world’s most biodiverse habitats, in areas predicted to experience severe climate change impacts. Like many other crops, coffee benefits from several ecosystem services (ES) that provide important inputs or conditions for production. Given coffee’s strong interactions with conservation, livelihoods, and climate change, it is important to understand the roles of biodiversity-regulated ES to coffee and how they are likely to change under future climates. Here we review the available literature on the provision of two essential and interacting ES that regulate coffee production: control of a beetle pest by birds and pollination by bees. Studies show that bird and bee communities provide pest control and pollination services that improve coffee quantity and quality, benefiting coffee farmers whose livelihoods depend on this crop. The literature also shows that a variety of plot, farm, and landscape management practices that support resources for bees and birds can enhance these ES. We also evaluate how these ES and their interactions may change under future climate change. Several studies have estimated likely climate impacts on coffee per se, but few have investigated climate vulnerability of pollination and pest control ES. Even less studies have quantified interactions between these ES. Although evidence is incomplete, managing coffee farms as diversified agroforestry systems could improve climate resilience of coffee cropping and communities of birds and bees, and therefore help farming families adapt to their changing environment. Based on our review, we identify six critical research priorities in this active area of study. Filling knowledge gaps would advance our understanding of interactions among landscapes, ES, and climate change, and would support climate adaptation for the millions of households whose livelihoods depend on coffee.

Experimental exclosure of birds and bats constitutes a powerful tool to study the impacts of wildlife on pests and crop yields in agricultural systems. Though widely utilized, exclosure experiments are not standardized across studies. Indeed, key differences surrounding the design, materials, and protocols for implementing field-based exclosure experiments of flying vertebrates increase heterogeneity across studies, and limit our understanding of biodiversity-friendly land use management. We reviewed the available literature on studies in which bird and bat exclosures were applied to study pest control in agricultural settings, and isolated 30 studies from both tropical and temperate land use systems, involving 12 crop types across 14 countries. Focusing on exclosure effects on crop yield, we analyzed effect detectability for a subset of suitable data. We then analyzed the potential of exclosure methods and possible extensions to improve our understanding of complex food webs and ecosystem services affecting the productivity of agricultural systems. While preferences exist in materials (e.g., nylon nets and bamboo frames), experimental exclosure studies of birds and bats differed greatly in their respective design, related costs, and effort — limiting the generalization and transferability of results at larger spatial scales. Most studies were based on experiments conducted in the United States and the Neotropics, mainly in coffee and cacao farms. A lack of preliminary or long-term data with repeated measurements makes it impossible to apply power analysis in most studies. Common constraints include, among other things, the choice of material and experimental duration, as well as the consideration of local versus landscape factors. We discuss such limitations, related common pitfalls, and options for optimization to inform improved planning, design, and execution of exclosure studies. By doing so, we aim to promote more comparable and transferable approaches in future field research on biodiversity-mediated ecosystem services.

Understanding how species functional traits relate to the delivery of ecosystem services is essential to support on-going biodiversity conservation efforts. While much recent work has been conducted, relatively few studies relating functional ecology to ecosystem services has utilized field experiments, particularly for animal species. We used a functional diversity (FD) approach to study the effect of bird traits on the control of the coffee berry borer (Hypothenemus hampei) and the effect of canopy cover management on bird FD. We conducted an exclosure experiment to test the effect of bird FD on the difference of H. hampei infestation rates between coffee shrubs both exposed to, and excluded from bird foraging activity. We addressed the following questions: (1) is avian FD, at the plot level, a good predictor of H. hampei infestation? (2) do gleaner bird species contribute to the control of the pest? and (3) how does shade management affect avian FD? We found that (1) all four FD indices calculated using bird traits were significant predictors of H. hampei differences in infestation rates, (2) richness of gleaning bird species was also a significant predictor of differences in H. hampei infestation rates, and (3) the interaction between month and canopy cover management affects bird FD, however whether this affects delivery of the pest control service remains unclear due to the particular biology of H. hampei. In revealing the connection between avian traits and the removal and potential control of H. hampei, our study highlights the importance of bird diversity persisting in agricultural landscapes, and the necessity of integrating bird conservation to foster healthy production systems.

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies., This work was supported through the National Socio-Environmental Synthesis Center (SESYNC) National Science Foundation Award DBI-1052875 for the project “Evidence and Decision-Support Tools for Controlling Agricultural Pests with Conservation Interventions” organized by D.S.K. and R.C.-K

Land clearing for agricultural use is a primary driver of biodiversity loss and fragmentation of natural ecosystems. Restoring natural habitat connectivity by retaining quality habitats and increasing on-farm tree cover contributes to species' mobility and persistence in agricultural landscapes. Nonetheless, remarkably few studies have quantified the impacts of on-farm practices for species' mobility measured as functional connectivity within the context of farm and broader spatial levels of landscape organization. We tested how adding and removing trees in different configurations on a farm comprised of coffee plantations and cattle pastures can help evaluate species’ mobility at the farmscape level (an area comprising the farm plus a 1.5 km buffer area). We coupled bird capture data and scenario modeling to assess species mobility of five neotropical bird species with distinct life history characteristics representing a gradient of forest dependency. We used seven years of mist-netting data to estimate species habitat affinity and to predict species mobility using the Circuitscape model across a 4371 ha farmscape in Costa Rica. Circuitscape allowed us to estimate changes in movement probability and relative changes in resistance to movement that species experience during dispersal (measured as resistance distance and passage area through which species can move) under four farmscape management scenarios. The four land-use scenarios included: (a) the 2011 farmscape land-use composition and configuration, b) converting all existing live fences to post-and-wire fence lines in the farm c) converting simplified coffee agroforests to multistrata coffee agroforests in the farm, and d) placing multistrata live fences around the perimeter of every parcel and roads on the farm. Model results suggest that existing multistrata live fences maintain the sporadic movement of all five species irrespective of forest dependence. Likewise, adding multistrata live fences around individual fields presents a more efficient strategy for increasing species mobility than multistrata coffee agroforestry systems in the assessed farmscape, by doubling the passage areas available to all species, although it created labyrinths with “dead-ends” for two species. While retaining large habitat patches remains important for conservation, managing on-farm connectivity complements these efforts by increasing movement probability and reducing dispersal resistance for forest-dependent bird species.

Ecosystem-service production is strongly influenced by the landscape configuration of natural and human systems. Ecosystem services are not only produced and consumed locally but can be transferred within and among ecosystems. The time and distance between the producer and the consumer of ecosystem services can be considered lags in ecosystem-service provisioning. Incorporation of heterogeneity and lag effects into conservation incentives helps identify appropriate governance systems and incentive mechanisms for effective ecosystem-service management. These spatiotemporal dimensions are particularly apparent in river—riparian systems, which provide a suite of important ecosystem services and promote biodiversity conservation at multiple scales, including habitat protection and functional connectivity. Management of ecosystem services with spatiotemporal lags requires an interdisciplinary consideration of both the biophysical landscape features that produce services and the human actors that control and be...

Ecologists and farmers often have contrasting perceptions about the value of natural habitat in agricultural production landscapes, which so far has been little acknowledged in ecology and conservation. Ecologists and conservationists often appreciate the contribution of natural habitat to biodiversity and potential ecosystem services such as biological pest control, whereas many farmers see habitat remnants as a waste of cropland or source of pests. While natural habitat has been shown to increase pest control in many systems, we here identify five hypotheses for when and why natural habitat can fail to support biological pest control, and illustrate each with case studies from the literature: (1) pest populations have no effective natural enemies in the region, (2) natural habitat is a greater source of pests than natural enemies, (3) crops provide more resources for natural enemies than does natural habitat, (4) natural habitat is insufficient in amount, proximity, composition, or configuration to provide large enough enemy populations needed for pest control, and (5) agricultural practices counteract enemy establishment and biocontrol provided by natural habitat. In conclusion, we show that the relative importance of natural habitat for biocontrol can vary dramatically depending on type of crop, pest, predator, land management, and landscape structure. This variation needs to be considered when designing measures aimed at enhancing biocontrol services through restoring or maintaining natural habitat.

Mesoamerica provides a unique context for biodiversity conservation in managed landscapes because of its geography, history of human intervention, and present conservation and development initiatives. The long and narrow form of the Mesoamerican landmass, and its division by a central mountain range, has served as both a bridge and a barrier. Conservation efforts in Mesoamerica are unique for the emphasis they place on regional connectivity through the Mesoamerican Biological Corridor and on biodiversity conservation in managed landscapes. The emphasis on conservation in agricultural systems has fostered innovations in payment for ecosystem services, and provides novel insights on the functional role that biodiversity plays in the provisioning of ecosystem services. The increasing rate of economic development in the region and the advent of new payment for ecosystem service schemes have provided new opportunities for forest regeneration and restoration. However, the small scale of private landholdings and the diversity of land uses featured in the region, while contributing to biodiversity conservation due to their structural and floristic complexity, present challenges for biodiversity monitoring and management.