Explore the vast range of titles available.

Local and landscape-scale agricultural intensification is a major driver of global biodiversity loss. Controversially discussed solutions include wildlife-friendly farming or combining high-intensity farming with land-sparing for nature. Here, we integrate biodiversity and crop productivity data for smallholder cacao in Indonesia to exemplify for tropical agroforests that there is little relationship between yield and biodiversity under current management, opening substantial opportunities for wildlife-friendly management. Species richness of trees, fungi, invertebrates, and vertebrates did not decrease with yield. Moderate shade, adequate labor, and input level can be combined with a complex habitat structure to provide high biodiversity as well as high yields. Although livelihood impacts are held up as a major obstacle for wildlife-friendly farming in the tropics, our results suggest that in some situations, agroforests can be designed to optimize both biodiversity and crop production benefits without adding pressure to convert natural habitat to farmland.

Agroforestry systems (AFS) are important agricultural land use in synergy with socio-environmental aspects, especially with cacao (Theobroma cacao L.) crop, a commodity mainly produced by smallholders in the humid tropics. In southern Pará, Brazilian Amazon, farmers manage native shade trees growing with cacao, but species selection may be not appropriate to AFS maintenance over time. The objective of this study was to understand the shade trees transition between successional management phases of cacao-AFS, considering its initial shade (IS) and secondary shade (SS). It was sampled 10 plots in each situation (20,000 m2 in total) identifying individuals with CBH ≥ 15 cm. As expected, floristic composition was different and SS had greater species richness and diversity than IS, where only 17% of species were the shared among them. Musa sp. and Carica papaya L. were found only in IS and were dominant species, representing almost a half of the individuals. Although there was increase of late succession species from IS to SS, this still keeps high abundance of early succession species, such as Cecropia sp. The result shows an unexploited potential products and gap of services provision, such as N-fixing. The conclusion highlights the necessity of long-term succession planning and management practices to guarantee cacao crop maintenance and improve diversification with other income sources, such as fruits and wood. The role of biodiversity conservation, provided by shade trees, should be the target of political strategies to encourage its maintenance, such as payment for ecosystems services or other economic incentives.

1. Avian ecosystem services such as the suppression of pests are considered to be of high ecological and economic importance in a range of ecosystems, especially in tropical agroforestry. However, how bird predation success is related to the diversity and composition of the bird community, as well as local and landscape factors, is poorly understood. 2. We quantified arthropod predation in relation to the identity and diversity of insectivorous birds using experimental exposure of artificial, caterpillar-like prey in 15 smallholder cacao agroforestry systems differing in local shade-tree management and distance to primary forest. The bird community was assessed using both mist-netting (targeting active understorey insectivores) and point counts (higher completeness of species inventories). 3. Bird predation was not related to local shade-tree management or overall bird species diversity, but to the activity of insectivorous bird species and the proximity to primary forest. Insectivore activity was best predicted by mist-netting-based data, not by point counts. We identified the abundant Indonesian endemic lemon-bellied white-eye Zosterops Moris as the main driver of prédation on artificial prey. 4. Synthesis and applications. The suppression of arthropods is a major ecosystem service provided by insectivorous birds in agricultural systems world-wide, potentially reducing herbivore damage on plants and increasing yields. Our results show that avian prédation success can be driven by single and abundant insectivorous species, rather than by overall bird species richness. Forest proximity was important for enhancing the density of this key species, but did also promote bird species richness. Hence, our findings are both of economical as well as ecological interest because the conservation of nearby forest remnants will likely benefit human needs and biodiversity conservation alike.

Background Shade trees in coffee agro ecosystem provide ecological and socio-economic benefits, including biodiversity conservation, microclimate regulation, and soil fertility maintenance. The Sheko semi-forest coffee system in southwestern Ethiopia is a traditional low-intensity landscape, yet its shade tree diversity, structure, and regeneration dynamics remain poorly documented. Methods Vegetation surveys were conducted across six purposively selected kebeles along an altitudinal gradient (950–1800 m a.s.l.) using 50 systematically placed plots (30 × 30 m). Each plot included five nested subplots (5 × 5 m) to assess seedlings and saplings. Shade trees were identified through field observations, local knowledge, and herbarium references. Structural attributes including density, basal area, diameter at breast height (DBH), height, and importance value index were measured. Data were analyzed using R 4.3.1 with descriptive statistics, ANOVA, correlation analyses, and Canonical Correspondence Analysis (CCA). Results A total of 31 shade tree species across 15 families and 23 genera were recorded, with 96.7% native. Moraceae (32.2%) and Fabaceae (16.1%) were dominant. Cordia africana Lam., Pouteria adolfi-friederici (Engl.) Baehni, and Antiaris toxicaria lesch accounted for over 50% of density and basal area, with Cordia africana having the highest IVI (36.3). DBH and height distributions indicated a mixed-aged population, yet seedlings and saplings were underrepresented, reflecting limited regeneration. Altitude showed no significant effect on species richness or density. Anthropogenic disturbances, including clearing and unsustainable harvesting, constrained natural regeneration. Conclusion The Sheko semi-forest coffee system supports high shade tree diversity but faces regeneration bottlenecks that threaten long-term sustainability. Targeted management, including enrichment planting and protection of key species, is essential to maintain ecosystem services and agroforestry resilience.

Cocoa yields in Côte d’Ivoire are low and falling each year, in part as a result of full-sun cropping systems. Thus, interest is now high in establishing sustainable cocoa agroforests through the re-introduction of shade trees. This article uses data collected from a sample of 400 cocoa farmers in the Soubré region of Côte d’Ivoire to rank the top alternative tree species of interest to farmers and to analyze the determinants of their presence and density in cocoa farms. Results show that the most significant determinants are: social network effects, ethnic group, and geographic zone. Also, poorer farmers and those in more isolated villages were more likely to associate their cocoa with crops popular for household consumption like oil palm. We thus suggest that future agroforestry programs should tailor the tree species promoted based on location, ethnic group, market access, and income level, and that extension programs should be designed to take advantage of networking effects.

Urban tree cover provides benefits to human health and well-being, but previous studies suggest that tree cover is often inequitably distributed. Here, we use National Agriculture Imagery Program digital ortho photographs to survey the tree cover inequality for Census blocks in US large urbanized areas, home to 167 million people across 5,723 municipalities and other Census-designated places. We compared tree cover to summer land surface temperature, as measured using Landsat imagery. In 92% of the urbanized areas surveyed, low-income blocks have less tree cover than high-income blocks. On average, low-income blocks have 15.2% less tree cover and are 1.5⁰C hotter than high-income blocks. The greatest difference between low- and high-income blocks was found in urbanized areas in the Northeast of the United States, where low-income blocks in some urbanized areas have 30% less tree cover and are 4.0⁰C hotter. Even after controlling for population density and built-up intensity, the positive association between income and tree cover is significant, as is the positive association between proportion non-Hispanic white and tree cover. We estimate, after controlling for population density, that low-income blocks have 62 million fewer trees than high-income blocks, equal to a compensatory value of$56 billion ($ 1,349/person). An investment in tree planting and natural regeneration of $17.6 billion would be needed to close the tree cover disparity, benefitting 42 million people in low-income blocks.

Coffee plantations have replaced many lower-montane forests in the Neotropics, and ongoing intensification is converting traditional polycultures with a variety of shade trees to plantations with no or monospecific shade trees. To evaluate the impact of coffee cultivation on epiphyte diversity, I surveyed vascular epiphytes on shade trees in nine different coffee plantations and compared records with those in four natural forests in central Veracruz, Mexico. Eighty-nine species occurred in coffee plantations, and 104 species occurred in natural forests. The number of epiphytic species in traditional polycultures with old shade trees, mostly of the genus Inga, was similar to that in forests, but plantations with small trees and sparse shade hosted fewer epiphytes than those with large trees. Epiphyte communities were, however, more homogeneous in coffee plantations than in forests, possibly because of a drier microclimate and the lack of large and long-lived trees. These results demonstrate the value of traditional polycultures for epiphyte diversity, show the importance of conserving large shade trees, and suggest that these coffee systems may not be suitable for all epiphytes.

The cultivation of cocoa has been an important driver of tropical deforestation globally. Efforts to reverse this trend are focusing on the reintroduction of shade trees to cocoa plantations. Shade trees are valuable in enhancing biophysical conditions on cocoa (Theobroma cacao) fields and contribute to biodiversity and product diversification for smallholder producers. Participatory trials of cocoa agroforests planted with indigenous shade tree species were undertaken with farmers in the Atwima District of the Ashanti Region of Ghana, to increase tree volume on cocoa fields while improving rural livelihoods and enhancing environmental sustainability. An ex ante financial analysis of the technology was undertaken to assess its economic viability. Input-output data were collected from farmer experiments over three seasons and supplemented with data from traditional cocoa fields of varying rotation ages, and secondary data on production in later years of an eighty-year cocoa rotation. A discounted cash flow analysis was carried out to estimate the benefit-cost (B/C) ratio, net present value (NPV), internal rate of return (IRR) and land expectation value (LEV) as well as the sensitivity to a 20% decline in cocoa prices and additional chemical costs for various shade scenarios at a 10% discount rate. It was observed that cocoa production is, in general, profitable. The change from the traditional system to one with hybrid cocoa raised the IRR from 31% to 57% with planted shade and 67% without, although extra agrochemical costs would tend to reduce the profitability of unshaded hybrid cocoa in particular. The age of maximum LEV for the various scenarios suggests that the optimum economic rotation for the hybrid cocoa is between 18 and 29 years, much less than the traditional system.

Productivity of coffee plantations is threatened by both climate change and decreasing revenues of coffee growers. Using shade trees might protect against temperature variability, erosion and excessive radiation but there may be trade-offs in productivity and quality. While impacts of shade trees on arabica ( Coffea arabica ) have been reviewed, a global synthesis on robusta ( Coffea canephora ) coffee is lacking. We assessed how shade affects robusta growth and productivity, and what are the interactions and trade-offs. We conducted a systematic literature search in Web of Science and CAB Abstracts on 16 December 2019. Thirty papers fulfilled our inclusion criteria of being experimental studies on the impact of overstory trees with approximately half being from Brazil or India. Shade improved robusta tree growth and yield with some contrasting effects on physicochemical and biochemical properties. Shade (> 30%) was associated with reduced beverage quality. Significant interactions between shade and location, rainfall level and robusta clone were found. Among the clones tested, 06V, C153, LB1, GG229 and JM2 showed a higher productivity and growth (from + 17 to + 280%) under moderate shade (41–65%). This is the first meta-analysis of the effects of shade on robusta coffee. By synthesizing data from different studies, we highlight for the first time that the effect of shade on robusta coffee depends on tree age. Shade had positive impacts on older robusta trees (mean of 16 years), while the impact of shade on younger trees was either insignificant or negative. We highlight the importance of both clone type and tree ages. Research gaps included a lack of knowledge on the effects of shade with respect to coffee and shade tree age as well as interactive effects. More in-depth studies are needed to understand the mechanisms of how shade trees affect robusta coffee.

BACKGROUND AND AIMS: Lobed leaves are considered selectively advantageous in conditions of high irradiance. However, most studies have involved woody species, with only a few considering the role of leaf lobation in herbaceous rosette species. In this study, it is hypothesized that, in addition to its adaptive value in high light, leaf lobation may add to the function of petioles as vertical spacers in herbaceous species in conditions of strong competition for light. METHODS: To test this hypothesis, leaf development was examined under seasonally changing natural light conditions and a field experiment was conducted in which light climate was manipulated in a wooded meadow population of Serratula tinctoria. KEY RESULTS: No changes in leaf lobation were observed in response to experimental shading or different natural light conditions. However, in tall herbaceous vegetation, plants with highly lobed leaves achieved significantly greater vertical elongation than plants with less-lobed leaves. In contrast to herbaceous shade, tree shade had no effect on leaf elongation, suggesting differential responsiveness to competition from neighbouring herbs versus overhead shade. In shading treatments, imposed shade could only be responded to by the elongation of leaves that were produced late in development. CONCLUSIONS: The results show that extensive leaf lobation can enable greater leaf elongation in response to shade from surrounding herbaceous vegetation. The different morphological responses displayed by Serratula tinctoria to different types of shade demonstrate the importance of critically assessing experimental designs when investigating phenotypic plasticity in response to shade.