Ecological intensification, or the improvement of crop yield through enhancement of biodiversity, may be a sustainable pathway toward greater food supplies. Such sustainable increases may be especially important for the 2 billion people reliant on small farms, many of which are undernourished, yet we know little about the efficacy of this approach. Using a coordinated protocol across regions and crops, we quantify to what degree enhancing pollinator density and richness can improve yields on 344 fields from 33 pollinator-dependent crop systems in small and large farms from Africa, Asia, and Latin America. For fields less than 2 hectares, we found that yield gaps could be closed by a median of 24% through higher flower-visitor density. For larger fields, such benefits only occurred at high flower-visitor richness. Worldwide, our study demonstrates that ecological intensification can create synchronous biodiversity and yield outcomes.

Smallholder-dominated agricultural mosaic landscapes are highlighted as model production systems that deliver both economic and ecological goods in tropical agricultural landscapes, but trade-offs underlying current land-use dynamics are poorly known. Here, using the most comprehensive quantification of land-use change and associated bundles of ecosystem functions, services and economic benefits to date, we show that Indonesian smallholders predominantly choose farm portfolios with high economic productivity but low ecological value. The more profitable oil palm and rubber monocultures replace forests and agroforests critical for maintaining above- and below-ground ecological functions and the diversity of most taxa. Between the monocultures, the higher economic performance of oil palm over rubber comes with the reliance on fertilizer inputs and with increased nutrient leaching losses. Strategies to achieve an ecological-economic balance and a sustainable management of tropical smallholder landscapes must be prioritized to avoid further environmental degradation.

Aim  Comparisons among islands offer an opportunity to study the effects of biotic and abiotic factors on small, replicated biological communities. Smaller population sizes on islands accelerate some ecological processes, which may decrease the time needed for perturbations to affect community composition. We surveyed ants on 18 small tropical islands to determine the effects of island size, isolation from the mainland, and habitat disturbance on ant community composition. Location  Thousand Islands Archipelago (Indonesian name: Kepulauan Seribu) off Jakarta, West Java, Indonesia. Methods  Ants were sampled from the soil surface, leaf litter and vegetation in all habitat types on each island. Island size, isolation from the mainland, and land‐use patterns were quantified using GIS software. The presence of settlements and of boat docks were used as indicators of anthropogenic disturbance. The richness of ant communities and non‐tramp ant species on each island were analysed in relation to the islands’ physical characteristics and indicators of human disturbance. Results  Forty‐eight ant species from 5 subfamilies and 28 genera were recorded from the archipelago, and approximately 20% of the ant species were well‐known human‐commensal ‘tramp’ species. Islands with boat docks or human settlements had significantly more tramp species than did islands lacking these indicators of anthropogenic disturbance, and the diversity of non‐tramp species decreased with habitat disturbance. Main conclusions  Human disturbance on islands in the Thousand Islands Archipelago promotes the introduction and/or establishment of tramp species. Tramp species affect the composition of insular ant communities, and expected biogeographical patterns of ant richness are masked. The island with the greatest estimated species richness and the greatest number of unique ant species, Rambut Island, is a forested bird sanctuary, highlighting the importance of protected areas in preserving the diversity of species‐rich invertebrate faunas.

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Land‐use change and agricultural intensification can strongly affect biodiversity in agricultural landscapes. Although many studies investigate management impacts, data on the long‐term change of species communities in agroecosystems are scarce. We analysed the long‐term change in diversity and composition of ant communities in cacao agroforestry systems in Central Sulawesi, Indonesia and attempted to disentangle the driving factors of this change. Ant communities were resampled in 2009 from sites for which previous surveys had been conducted either in 2001 (the rainforest‐poor Palolo region) or 2003 (the rainforest‐rich Kulawi region) using insecticide fogging. Ant community composition changed significantly over time in Palolo and Kulawi. The change in ant species richness differed between regions. Species richness increased in Kulawi, probably due to the increasing availability of nest sites and microhabitats as trees grow larger and older. In the Palolo region, species richness decreased, suggesting that the high local intensification and landscape‐wide changes may have counteracted the effects of tree age. Changes in ant communities over time were significant, but were more difficult to explain than expected, despite clear difference in management changes within and between regions. The findings suggest that the landscape‐scale differences between the two study regions play a more important role for species diversity and its composition than changes in local management. This highlights the importance of long‐term studies across contrasting landscapes for better understanding the consequences land‐use intensification has on tropical biodiversity.

1 The expansion of agricultural fields is the main cause of landscape simplification and changes in the composition and configuration of landscapes. These landscape changes influence pests and their natural enemies, and may influence their interaction and the biological control services to which they contribute. However, the effects of landscape composition can vary between region and insect species. 2 The present study was conducted on cucumber plants in 16 different sites of varying landscape composition in Bogor and its surrounding area, West Java, Indonesia. Sampling of insects was performed on lepidopteran pests and their parasitoids. 3 The results obtained showed that landscape composition (i.e. patch number of cropland) had a positive impact on the abundance of parasitoids and their host (lepidopteran pests). Yet the proportion of natural habitat did not influence parasitoid abundance and their host-parasitoid interaction. The presence of Apanteles taragamae (i.e. the most abundant parasitoid) in the agricultural landscape was affected by the abundance of its hyperparasitoid and its host (Diaphania indica) and not by landscape composition. 4 The findings of the present study suggest that the higher proportion of patchy cropland in tropical agricultural landscapes, as well as agricultural practices, can maintain parasitoid abundance and functional diversity and, finally, an enhanced parasitism rate.

Buchori D, Rizali A, Rahayu GA, Mansur I. 2018. Insect diversity in post-mining areas: Investigating their potential role as bioindicator of reclamation success. Biodiversitas 19: 1696-1702. Reclamation can be a pivotal process to return an ecosystem to its condition prior to human disturbance, by recreating a landscape so that its structure and function closely resemble a natural community. Unfortunately, there is a lack of empirical data as to whether reclamation efforts successfully establish sustainable of the ecosystem or not. The objective of this research was to study insect diversity in post-mining areas and investigate their potential role as bioindicators of reclamation success. An ecological research was conducted in post-mining reclamation areas managed by PT. Berau Coal in Binungan, East Kalimantan. We selected sub-areas that had been subject to reclamation efforts for varying periods, ranging from 2 to 10 years, for observation. We also used an area of undisturbed natural forest as a comparison. Inside each of these subareas of different reclamation age, insects were sampled using pitfall traps and malaise traps along a 100-meter transect. Our results showed that insect diversity differed in areas of different reclamation age. Based on CCA revealed that environmental factors i.e. pioneer tree age, vegetation diversity and soil chemistry (N total) affected the diversity of insects in the reclamation area. In particular, NMDS analysis showed different species composition in ant communities found in subareas of varying reclamation age. We conclude that ants are the most useful potential bioindicator to assess reclamation success in post-mining areas.

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