Vocal response of oriental magpie robin (Copsychus saularis) to urban environmental factors in Peninsular Malaysia

Anthropogenic noise and changes in environmental gradients resulted from urbanisation have been shown to alter vocalisation of urban birds in previous studies. This study examined the vocalisation of the Oriental Magpie Robin (Copsychus saularis; locally known as Murai Kampung) in relation to anthropogenic noise and environmental factors in the urban, suburban and rural areas in Peninsular Malaysia. We measured four ambient factors (i.e. ambient noise, temperature, relative humidity and light intensity) and two landscape factors (i.e. distance to building and distance to major roads) between January and June 2017 from six locations. A total of 147 recordings comprising territorial songs of the bird were obtained and transcribed into spectrograms. Six parameters, namely low frequency, high frequency, frequency ranges, length of strophe, number of elements per strophe, and time interval between strophes were derived from spectrograms for each recording. In urban areas, low frequency of the songs was found to have increased significantly as compared to those recorded in suburban and rural areas. The difference in noise, temperature and relative humidity in urban and suburban environment had led to both single and interaction effects towards the Oriental Magpie Robin’s song parameters, i.e. low frequency, length of strophe, time interval between strophes and number of elements per strophe. The results evidenced the ability of the Oriental Magpie Robin in regulating and altering their song structure according to its surrounding environment. This implies its vocal plasticity which is important in ensuring the efficiency in transmission of songs and is likely to explain why the bird is less susceptible to urbanisation

Testing the effectiveness of the Forest Integrity Assessment: a field-based tool for estimating the condition of tropical forest

1. Global targets to halt biodiversity losses and mitigate climate change will require protecting rainforest beyond current protected area networks, necessitating responsible forest stewardship from a diverse range of companies, communities and private individuals. Robust assessments of forest condition are critical for successful forest management, but many existing techniques are highly technical, time-consuming, expensive, or require specialist knowledge. 2. To make assessment of tropical forests accessible to a wide range of actors, many of whom may be limited by resources or expertise, the High Conservation Value Resource Network (HCVRN), with the SE Asia Rainforest Research Partnership (SEARRP), developed a South East Asian version of the Forest Integrity Assessment (FIA) tool as a rapid (< 1 hour) method of assessing forest condition in the field, where non-experts respond to 50 questions about characteristics of the local environment while walking a site transect. Here, we examined the effectiveness of this survey tool by conducting ~ 1,000 assessments of forest condition at 16 tropical rainforest sites with varying levels of disturbance in Sabah, Malaysian Borneo. 3. We found good agreement (R-squared range: 0.50 – 0.78) between FIA survey scores and independent measures of forest condition, including biodiversity, vegetation structure, aboveground carbon, and other key metrics of ecosystem function, indicating that the tool performed well. Although there was variation among assessor responses when surveying the same forest sites, assessors were consistent in their ranking of those sites, and prior forest knowledge had a minimal effect on the FIA scores. Revisions or further training for questions where assessors disagree, for example on the presence of fauna at a site, could improve consistency. 4. We conclude that the FIA survey tool is a robust method of assessing forest condition, providing a rapid and accessible means of forest conservation assessment. The FIA tool could be incorporated into management practices in a wide range of forest conservation schemes, from sustainability standards, to community forestry and restoration initiatives. The tool will enable more organisations and individuals to understand the conservation value of the forests they manage, and to identify areas for targeted improvements

Supporting decision-making by companies in delivering their climate net-zero and nature recovery commitments: synthesizing current information and identifying research priorities in rainforest restoration

Many companies are making ambitious pledges to achieve positive impacts for climate and nature by financing restoration of carbon- and biodiversity- rich natural habitats. However, companies cannot make evidence-based choices that will deliver successful restoration if the scientific information required to guide investment has not been synthesised in a way that they can use, or there are knowledge gaps. To explore this issue, share information, and identify knowledge gaps and research priorities, we bring together researchers, a conservation NGO and a multinational consumer goods company (Unilever), focusing on Southeast Asian rainforests. These habitats offer significant restoration opportunities for carbon and biodiversity in areas that have been degraded by commercial logging and agriculture. We find that procedures for carbon restoration are much better developed than those for biodiversity, and that new research is urgently needed to deliver evidence-based biodiversity restoration. Companies need to be confident that their actions are fit-for-purpose to meet their environmental pledges. Achieving successful restoration outcomes will require co-designed projects with the potential to deliver positive co-benefits for carbon, biodiversity and local livelihoods

Land-use change and propagule pressure promote plant invasions in tropical rainforest remnants

Context: Intact tropical rainforests are considered robust to plant invasions. However, land-use change alters the structure and species composition of native forest, opening up tropical landscapes to invasion. Yet, the relative roles of key drivers on tropical forest invasions remain little investigated. Objectives: We examine factors affecting plant invasion of rainforest remnants in oil-palm dominated landscapes in Sabah, Malaysian Borneo. We hypothesized that invasion is greater in highly fragmented landscapes, and in disturbed forests with lower native plant diversity (cf. old-growth rainforests). Methods: Native and exotic plants were surveyed in 47 plots at 17 forest sites, spanning gradients in landscape-scale fragmentation and local forest disturbance. Using partial least squares path-modelling, we examined correlations between invasion, fragmentation, forest disturbance, propagule pressure, soil characteristics and native plant community. Results: We recorded 6999 individuals from 329 genera in total, including eight exotic species (0–51% of individuals/plot, median = 1.4%) representing shrubs, forbs, graminoids and climbers. The best model (R2 = 0.343) revealed that invasion was correlated with disturbance and propagule pressure (high prevalence of exotic species in plantation matrix), the latter being driven by greater fragmentation of the landscape. Our models revealed a significant negative correlation between invasion and native tree seedlings and sapling community diversity. Conclusions: Increasing landscape fragmentation promotes exotic plant invasion in remnant tropical forests, especially if local disturbance is high. The association between exotic species invasion and young native tree community may have impacts for regeneration given that fragmentation is predicted to increase and so plant invasion may become more prevalent

Conservation set-asides improve carbon storage and support associated plant diversity in certified sustainable oil palm plantations

Maintaining forest conservation set-asides is a key criterion of sustainability certification of many crops that drive tropical deforestation, but their value for carbon storage and associated biodiversity is unclear. We conducted vegetation measurements to examine the benefits of set-asides for aboveground carbon stocks (AGC) in certified oil palm plantations on Borneo, and whether their AGC is positively associated with plant diversity. The mean estimated AGC of live trees and palms ≥10 cm diameter in set-asides in certified oil palm plantations (52.8 Mg ha−1) was >1.5-times that of oil palm (30.3 Mg ha−1), with some plots supporting similar AGC to primary forest. For lowland Borneo, we estimate that the average AGC of oil palm plantations with 10% coverage of set-asides is up to 20% greater than the average AGC of oil palm plantations without set-asides, newly demonstrating carbon storage as a benefit of conservation set-asides. We found positive relationships between AGC and plant diversity, highlighting the carbon–biodiversity co-benefits of set-asides. However, set-asides had a lower density of tree seedlings than continuous primary forest, indicating potential suppression of future tree regeneration and AGC. Our findings support the application of zero-deforestation during agricultural development, to conserve areas of remaining forest with high AGC and high biodiversity. We recommend management practices that boost regeneration in existing set-asides (e.g. enrichment planting), which would be most effective in larger set-asides, and could substantially increase the AGC of agricultural landscapes without removing land from production, and help conserve forest-dependent biodiversity

Vocal response of oriental Magpie Robin (Copsychus saularis) to urban environmental factors in Peninsular Malaysia

Anthropogenic noise and changes in environmental gradients resulted from urbanisation have been shown to alter vocalisation of urban birds in previous studies. This study examined the vocalisation of the Oriental Magpie Robin(Copsychus saularis; locally known as Murai Kampung) in relation to anthropogenic noise and environmental factors in the urban, suburban and rural areas in Peninsular Malaysia. We measured four ambient factors (i.e. ambient noise, temperature, relative humidity and light intensity) and two landscape factors (i.e. distance to building and distance to major roads) between January and June 2017 from six locations. A total of 147 recordings comprising territorial songs of the bird were obtained and transcribed into spectrograms. Six parameters, namely lowfrequency, high frequency, frequency ranges, length of strophe, number of elements per strophe, and time interval between strophes were derived from spectrograms for each recording. In urban areas, low frequency of the songs was found to have increased significantly as compared to those recorded in suburban and rural areas. The difference in noise, temperature and relative humidity in urban and suburban environment had led to both single and interaction effects towards the Oriental Magpie Robin’s song parameters, i.e. low frequency, length of strophe, time interval between strophes and number of elements per strophe. The results evidenced the ability of the Oriental Magpie Robin in regulating and altering their song structure according to itssurrounding environment. This implies its vocal plasticity which is important in ensuring the efficiency in transmission of songs and is likely to explain why the bird is less susceptible to urbanisation

The road to recovery: a synthesis of outcomes from ecosystem restoration in tropical and sub-tropical Asian forests.

Current policy is driving renewed impetus to restore forests to return ecological function, protect species, sequester carbon and secure livelihoods. Here we assess the contribution of tree planting to ecosystem restoration in tropical and sub-tropical Asia; we synthesize evidence on mortality and growth of planted trees at 176 sites and assess structural and biodiversity recovery of co-located actively restored and naturally regenerating forest plots. Mean mortality of planted trees was 18% 1 year after planting, increasing to 44% after 5 years. Mortality varied strongly by site and was typically ca 20% higher in open areas than degraded forest, with height at planting positively affecting survival. Size-standardized growth rates were negatively related to species-level wood density in degraded forest and plantations enrichment settings. Based on community-level data from 11 landscapes, active restoration resulted in faster accumulation of tree basal area and structural properties were closer to old-growth reference sites, relative to natural regeneration, but tree species richness did not differ. High variability in outcomes across sites indicates that planting for restoration is potentially rewarding but risky and context-dependent. Restoration projects must prepare for and manage commonly occurring challenges and align with efforts to protect and reconnect remaining forest areas. The abstract of this article is available in Bahasa Indonesia in the electronic supplementary material. This article is part of the theme issue 'Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration'