Are we using the most appropriate methodologies to assess the sensitivity of rainforest biodiversity to habitat disturbance?

Accurately assessing how biodiversity responds in the Anthropocene is vital. To do so, a number of indicator taxa are commonly used to monitor human-impacted forests and the subsequent recovery of their biodiversity. This makes monitoring more economically feasible, yet only valuable if the responses observed truly reflect the status of biodiversity. Many challenges exist for getting this monitoring right, including choosing the most effective indicators and ultimately choosing the most appropriate methods to capture trends. We have reason to believe that the methods currently used to assess humanimpacted tropical forest might be misrepresenting trends related to the degree of impact of disturbance to biodiversity and to the value of secondary forests for biodiversity conservation. Using recent case studies that assessed butterflies, we challenge the paradigm that fruit-baited butterfly traps are the best method for assessing human-impacted tropical forests, and that their use solely along the forest floor is underestimating the impacts to biodiversity in tropical forests. We suggest that alternative or additional methods could provide a more representative picture of the overall butterfly biodiversity responses to human-impacted tropical forests and that similar assessments of other groups and methods should be carried out

Food for thought. Rainforest carrion-feeding butterflies are more sensitive indicators of disturbance history than fruit feeders

Tropical forests have, and in many areas continue to experience both severe and subtle forms of human disturbance; most commonly from hunting, logging and clearance for agriculture. The ability to detect a full range of impacts is essential to understanding how biodiversity responds to human disturbance. Since monitoring the entire biodiversity of a tropical forest is an impossible task, specific groups of biodiversity are often used as biological indicators. Due to their relative ease in detection and identification, their sensitivity to environmental change and their short generation time, butterflies are suggested to be one of the most effective biodiversity indicators for tropical forest monitoring. However, most biodiversity monitoring of tropical ecosystems using butterflies relies only on one sub-group, the fruit-feeding butterflies, or Nymphalidae. Here we assess for the first time if the use of carrion-feeding butterfly communities might improve our ability to detect and monitor human impacts and conservation management outcomes in tropical forests. We analysed species richness, abundance and community composition of rainforest fruit and carrion butterfly communities to see how effectively they detect known differences in forest disturbance history, between three different vertical strata of rainforest, and assess whether they provide stable results across different seasons. We found that compared to fruit-feeding butterflies, sampling carrion-feeders detected greater species richness and abundance for the same survey effort, detected more pronounced effects of known differences in historic disturbance, and showed greater temporal stability in biodiversity patterns across the year. We also identify for the first time a series of indicator butterfly species and tribes that could be used as biological indicators to study biodiversity responses to human disturbance and differences across vertical strata of the rainforest. We therefore suggest that carrion-feeding butterfly communities will be a powerful addition to the family of indicators groups that are available for monitoring the impacts of human disturbance on tropical biodiversity. © 201

Indigenous Lands are Better for Amphibian Biodiversity Conservation Than Immigrant-Managed Agricultural Lands: A Case Study From Manu Biosphere Reserve, Peru

The efficacy of protected areas is tied to the management of surrounding areas. Still, the importance of buffer zones for biodiversity conservation is overlooked. Manu Biosphere Reserve is one of the most biodiverse places on earth, yet destructive land-use practices are degrading the ecological integrity of its buffer zone. To better understand the importance of different land-uses within Manu’s buffer zone for biodiversity conservation, we assessed amphibian communities across a land-use gradient in the buffer zone (immigrant agricultural land, forests used by three Indigenous communities, and a regenerating forest), in addition to a reference site in its core protected area. We surveyed six sites and sampled amphibian communities using visual encounter surveys and leaf litter searches over dry and wet seasons. Overall, in 2249 ha surveyed of the buffer zone, we recorded 70 amphibian species (57% of the 124 species recorded in the Manu Biosphere Reserve from the same elevational range within our study). Species richness, evenness, and diversity of amphibians decreased with habitat degradation and were lowest in the agricultural land. Conversely, the richness and diversity of amphibians in the regenerating forest and the Indigenous communities’ forests were similar to that of the core protected area, and each had a relatively unique community composition, whereas the agricultural land was dominated by generalist species. Our results suggest that increasing degradation through expanding agriculture traditionally adopted by immigrant communities could significantly threaten biodiversity within the buffer zone. However, our findings also underscore the high potential of buffer zones managed by Indigenous communities for biodiversity conservation. A combination of sustainable livelihood activities, cultural practices, and forest protection, as observed in many Indigenous communities, is critical to fulfilling the role of a Biosphere Reserve—to reconcile the conservation of biological and cultural diversity while improving social and economic development

Human disturbance impacts on rainforest mammals are most notable in the canopy, especially for larger‐bodied species

Aim: Community‐level assessments of how biodiversity responds to disturbance within forest habitats are often biased towards terrestrial‐based surveys. However, recent research suggests that arboreal communities of several indicator groups (ants, amphibians, beetles and butterflies) are more susceptible to human disturbance than their terrestrial counterparts, but what about wildlife at higher trophic levels? We assess responses to disturbance, from forest floor to canopy, of a key conservation flagship group: medium to large rainforest mammals. Location: The Manu Biosphere Reserve, southeast Peru. Methods: We deploy both arboreal and terrestrial camera traps to directly compare the response of arboreal and terrestrial mammal communities to rainforest degradation and disturbance. Results: We show that the arboreal mammal community is more susceptible to habitat disturbance than the terrestrial community. Furthermore, the largest‐bodied arboreal species, which are major seed dispersers, showed the greatest negative response to forest disturbance. The strongest predictors of occupancy probability for arboreal communities were focal tree connectivity and canopy cover, whereas surrounding forest loss and canopy height were there strongest predictors of terrestrial community occupancy, although these also had effects similar in size and magnitude on the arboreal community. Main conclusions: Conservation conclusions drawn from camera‐based studies focused on the terrestrial realm likely underestimate the impact of rainforest degradation to arboreal communities and on arboreal rainforest biodiversity in general. We highlight the importance of implementing arboreal research methods, capable of investigating conservation implications of anthropogenic disturbance across all vertical strata, for accurate conservation assessments and improving rainforest management and restoration strategies

Trick or treat? Pollinator attraction in Vanilla pompona (Orchidaceae)

Natural pollination of Vanilla species remains poorly understood. Our research aimed at better understanding the pollinator attraction mechanism of the Neotropical species Vanilla pompona. Based on our results, we hypothesize that the identified pollinator Eulaema cingulata is attracted via a dual mechanism combining floral fragrance rewards and food deception