Aligning crop production with conservation initiatives has long been a topic of debate, with agricultural intensification threatening biodiversity across the globe. Shade-grown coffee allows farmers to preserve biodiversity by providing viable habitat, but its conservation value remains unclear. In this meta-analysis, we screened existing literature using the PRISMA protocol to compare the effect of three shade intensities on species diversity and individual abundance: sun, low shade (LS) and high shade (HS). Furthermore, we examine differences between taxa, within taxa and between regions to establish which species benefit most from shade and whether these benefits vary dependent on geographical location. Out of 1889 studies, we included 69 studies in the analysis, and performed random-effects meta-analyses and meta-regressions. Overall, we found that species diversity was significantly higher in HS when compared to sun and LS, and species diversity in LS tended to be higher than in sun. In each treatment, the species diversity of birds was higher in the higher shade treatment, i.e., HS and LS. In addition, mammal and epiphyte species diversity was higher in HS when compared to LS. Similarly, studies from Latin America showed significantly higher species diversity and abundance in shaded farms when compared to sun farms. Studies conducted in Africa detailed the opposite relationship, with abundance being significantly higher in less shaded systems, highlighting that land-use strategies must be region-specific. Moving forward, strategies to conserve biodiversity within coffee farms should: 1) account for region-specific variables; 2) end further encroachment; 3) maintain connectivity; and 4) optimise yield through prioritising faunal and floral diversity.

Soil quality can directly influence the health, yield, and quality of a particular crop species, and agrochemicals are often used to boost soil micro- and macro-nutrients. The excessive application of agrochemicals, however, is often the cause of imbalances in acidity and nutrient concentration and can cause soil to deteriorate. The presence of multiple shade trees in farmland can positively influence soil quality. Here, we evaluate the effect of agrochemical use (i.e., organic, mixed, and intensive) and shade tree complexity (i.e., sun, low, and high) on soil quality (i.e., pH, macronutrients, and micronutrients) in 56 coffee home gardens in Indonesia. We found that Al, Fe, K, and Mn were significantly higher in farms that used agrochemicals, and pH was more acidic in fields with intensive use of agrochemicals. C:N ratio and Mn were higher in soils with high shade complexity than in sun-exposed soils. The use of agrochemicals, however, is not sustainable as it increases the Al concentration and decreases pH, both of which are associated with poor coffee growth and reduced soil quality. Shade tree removal and the use of invasive, non-native species, such as eucalyptus, can also negatively influence soil quality, and thus the maintenance of complex shade cover with native trees should be prioritised.

As road infrastructure networks rapidly expand globally, especially in the tropics, previously continuous habitats are being fragmented, resulting in more frequent wildlife–vehicle collisions (WVC). Primates are widespread throughout many sub-/tropical countries, and as their habitats are fragmented, they are increasingly at risk of WVC. We created the Global Primate Roadkill Database (GPRD), the largest available standardized database of primate roadkill incidents. We obtained data from published papers, un-published and citizen science databases, anecdotal reports, news reports, and social media posts. Here, we describe the collection methods for the GPRD and present the most up-to-date version of the database in full. For each primate roadkill incident, we recorded the species killed, the exact location, and the year and month the roadkill was observed. At the time of publication, the GPRD includes 2862 individual primate roadkill records from 41 countries. As primates range in more than twice as many countries, the absence of data from these countries is not necessarily indicative of a lack of primate vehicular collisions. Given the value of these data for addressing both local and global research questions, we encourage conservationists and citizen scientists to contribute to the GPRD so that, together, we can better understand the impact road infrastructure has on primates and evaluate measures which may help mitigate risk-prone areas or species.

Pollination services, from both wild and managed populations of insect pollinators, have degraded as a result of agricultural intensification. Whilst 75% of economically important crops depend on insect pollinators for cultivation, 40% of insect pollinator species are threatened with extinction. Pollination services must be preserved if there is to be enough food for a global population whose demand is expected to double, if not triple, by 2050. Pollinator diversity and pollinator efficiency have been found to increase as a result of wildlife-friendly farming practices (i.e., natural chemicals and fertilizers and agroforestry). We evaluated the presence of insect pollinators in 42 coffee home gardens in West Java, Indonesia. Via generalized linear mixed models, we found that number of visitor species (β = 0.418 ± SE 0.194, p = 0.031) and visitation time (β = 0.845 ± SE 0.308, p = 0.006) decreased as farms were more intensely managed, (i.e., used chemical pesticides), compared to fields using organic practices. As knowledge of pollination services is widespread amongst smallholder farmers in Indonesia and beyond due to the long-held tradition of beekeeping, these results will add to their existing knowledge and empower farmers to enhance resources for pollinator species through agroforestry and natural pest management. Although we found significant differences in pollination services provided in intensely managed and wildlife-friendly farms, chemical use can affect farms far beyond a particular area of production. Therefore, pollinator conservation must be applied at a landscape level and involve all stakeholders, including farmers, when making effective policies.

Expansion and intensification of agricultural land in the tropics increasingly raises environmental concerns and questions about sustainability of production systems. A key parameter to consider when assessing the sustainability of production systems is soil fertility, and of particular interest are macronutrients, pH, electrical conductivity, and microbial communities. To understand which environmental factors influence soil fertility, we studied the abovementioned key parameters in two agroforestry systems (rustic and polyculture) in Bali, Indonesia. Via Generalized Linear Models, we found that agroforestry system, canopy cover, crop richness, tree richness, and yields had differing effects on topsoil (0–5 cm) and subsoil (10–15 cm) properties, including C:N ratios, conductivity, K, organic C, P, and total microbes. We found a higher C:N ratio in topsoil (p = 0.027), higher organic carbon content in topsoil (p = 0.009) and subsoil (p < 0.001), higher total microbes in subsoil (p = 0.001), and lower phosphorus levels in topsoil (p < 0.001) in rustic than in polyculture systems. Rustic systems may foster conditions conducive to soil fertility, and in our study, canopy cover (p < 0.001) and tree richness (p < 0.001) emerge as a key positive drivers of the total number of microbes in topsoil. The positive associations observed between crop and tree richness with electrical conductivity and total microbe counts underscore the importance of biodiversity in enhancing soil fertility, emphasizing the need for diversified agricultural systems to promote soil fertility. With soil fertility declining across the world due to global investments in agricultural intensification, it is vital that food production systems divert to the use of systems such as agroforestry in order to ensure soil sustainability and food security for future generations.