Variable responses of individual species to tropical forest degradation

The functional stability of ecosystems depends greatly on interspecific differences in responses to environmental perturbation. However, responses to perturbation are not necessarily invariant among populations of the same species, so intraspecific variation in responses might also contribute. Such inter-population response diversity has recently been shown to occur spatially across species ranges, but we lack estimates of the extent to which individual populations across an entire community might have perturbation responses that vary through time. We assess this using 524 taxa that have been repeatedly surveyed for the effects of tropical forest logging at a focal landscape in Sabah, Malaysia. Just 39 % of taxa – all with non-significant responses to forest degradation – had invariant responses. All other taxa (61 %) showed significantly different responses to the same forest degradation gradient across surveys, with 6 % of taxa responding to forest degradation in opposite directions across multiple surveys. Individual surveys had low power (< 80 %) to determine the correct direction of response to forest degradation for one-fifth of all taxa. Recurrent rounds of logging disturbance increased the prevalence of intra-population response diversity, while uncontrollable environmental variation and/or turnover of intraspecific phenotypes generated variable responses in at least 44 % of taxa. Our results show that the responses of individual species to local environmental perturbations are remarkably flexible, likely providing an unrealised boost to the stability of disturbed habitats such as logged tropical forests

Thresholds for adding degraded tropical forest to the conservation estate

Peer reviewe

Thresholds for adding degraded tropical forest to the conservation estate

Logged and disturbed forests are often viewed as degraded and depauperate environments compared with primary forest. However, they are dynamic ecosystems1 that provide refugia for large amounts of biodiversity2,3, so we cannot afford to underestimate their conservation value4. Here we present empirically defined thresholds for categorizing the conservation value of logged forests, using one of the most comprehensive assessments of taxon responses to habitat degradation in any tropical forest environment. We analysed the impact of logging intensity on the individual occurrence patterns of 1,681 taxa belonging to 86 taxonomic orders and 126 functional groups in Sabah, Malaysia. Our results demonstrate the existence of two conservation-relevant thresholds. First, lightly logged forests (68%) of their biomass removed, and these are likely to require more expensive measures to recover their biodiversity value. Overall, our data confirm that primary forests are irreplaceable5, but they also reinforce the message that logged forests retain considerable conservation value that should not be overlooked

Optimising the recovery of degraded tropical rainforest logging estates

Tropical forests comprise 40% of the Earth’s terrestrial carbon sink, converting carbon dioxide into biomass. The natural flux of carbon in forests is controlled by growth and decomposition of biomass; processes which can be influenced by human activity. Southeast Asia’s history of intensive commercial logging has interrupted these natural processes, with 70% of extant forests now degraded. Despite their prevalence, logged forests are not studied as widely as primary forests. Data on belowground biomass and root systems is particularly scarce. Malaysian Borneo has been a global hotspot for timber production over the past century, often at greater rates than were considered sustainable. This casts doubt on whether heavily degraded forests will regenerate naturally within the expected timeframe of approximately 60-80 years. This thesis aims to fill these knowledge gaps by investigating the above and belowground biomass of Bornean forests along a degradation gradient, from highly degraded salvage-logged forests, to lightly logged forest, through to pristine primary forests. First, we trialled LiDAR and photogrammetry for generating 3D imagery of tree root systems using low-cost, handheld technology. We then used this technique to digitally capture the root system architecture of Macaranga trees excavated in Borneo and determined the biomass root:shoot ratio. Finally, we used data from an eight-year vegetation census across the degradation gradient to parameterise a simulation of biomass regeneration in logged forests. We found that the pioneer species in regenerating forests have a higher root:shoot ratio than is found in a primary forest and that Macaranga tree roots form complex networks by inosculating with their neighbours. Our simulation indicates that by 2050, most salvage-logged forests will remain degraded. We also showed that primary forests can continue to gain large amounts of biomass year-on-year. The outputs from this research can support restoration activities, advise sustainable logging, and improve local carbon accounting.Open Acces

Deforestation in Belize-What, Where and Why

AbstractThe tropical forests of Belize are a dynamic environment influenced by much disturbance throughout their natural history. In recent times, logging and agriculture have once more become the dominant drivers of land use change, yet the Belizean forests remain some of the most complete swathes of forest in the region. However, it is largely unknown how the abundance of specific forest types has changed. This study aims to critically assess whether valuable habitat types have been disproportionately affected by deforestation between 1986 and 2018. ENVI Classic 5.5 was used to calculate the NDVI values of Landsat imagery, with values over 0.6 deemed to indicate primary forest. ArcMap 10.6 was used for detecting change in forest cover between 1986 and 2018, in addition to digitising colonial maps. Results show variation in the percentage of forest lost between habitat types, with a bias towards forests fragmented by or replaced by agriculture, particularly in the north and along the Guatemalan border. The protected area network was found overall to have little influence on deforestation, though this varies between reserves. Of the three forest types experiencing the highest percentage of forest loss, only Ensino-Pixoy occurs exclusively outside protected areas. Cohune Santa-Maria and Sapote-Mahogany are found at least partially within protected areas and experience loss within them. Analysis of IUCN ratings of forest species revealed data deficiency, particularly concerning taxa indigenous to Mesoamerica, against which this study recommends further vegetation studies. to allow recommendations for protection of particularly threatened forest types. A review of management strategies in protected areas, especially the Caracol Archaeological Reserve, is necessary to avert the worrying deforestation trends this study has identified. The country-wide deforestation data can be used to advise future forest policy as well as calculation of national carbon stocks or determining integrity of ecosystem services.</jats:p

From pledges to places: action agendas need spatial data to integrate climate and biodiversity action

As COP30 approaches, policymakers must ensure that the integration of climate and biodiversity action by non-state and subnational actors is anchored in spatial data. Otherwise, we cannot see where change is happening, how effective it is, or who bears costs and benefits. The UNFCCC Global Climate Action and CBD Action Agenda Portals should lead by requiring spatial details on implementation, enabling more credible and participatory monitoring, analysis, and collaboration

From pledges to places: action agendas need spatial data to integrate climate and biodiversity action

As COP30 approaches, policymakers must ensure that the integration of climate and biodiversity action by non-state and subnational actors is anchored in spatial data. Otherwise, we cannot see where change is happening, how effective it is, or who bears costs and benefits. The UNFCCC Global Climate Action and CBD Action Agenda Portals should lead by requiring spatial details on implementation, enabling more credible and participatory monitoring, analysis, and collaboration

Thresholds for adding degraded tropical forest to the conservation estate.

Acknowledgements: This study was supported by funding to the Stability of Altered Forest Ecosystems Project by the Sime Darby Foundation. Research permission and site access were provided by the Maliau Basin Management Committee, the Sabah Foundation, Benta Wawasan, Sabah Softwoods, the Innoprise Foundation, the Sabah Forestry Department and the Sabah Biodiversity Centre. R.M.E. is supported by the NOMIS Foundation. Data collection was financed by Australian Research Council grant DP140101541; Bat Conservation International; the British Council Newton-Ungku Omar Fund 216433953; British Ecological Society grant 3256/4035; the Cambridge Trust; the Cambridge University Commonwealth Fund; the Czech Science Foundation (14-32302S); the European Research Council (281986); the European Social Fund and the Czech Republic (CZ.1.07/2.3.00/20.0064); the Fundamental Research Grant Scheme (FRG0302-STWN-1/ 2011), Ministry of Higher Education, Malaysia; FFWS CZU (IGA number A_26_22); the Jardine Foundation; Malaysia Industry Group for High Technology (216433953); the Ministry of Education, Youth and Sports of the Czech Republic (INTER-TRANSFER LTT19018); the Panton Trust; the Primate Society of Great Britain; ProForest; Royal Society of London grant RG130793; the Sime Darby Foundation; the S. T. Lee Fund; the Sir Philip Reckitt Educational Trust; the Tim Whitmore Fund; the Universiti Malaysia Sabah; the University of East Anglia; the University of Kent; the University of Florida Institute of Food and Agricultural Sciences; UK Research and Innovation Natural Environment Research Council grants NE/H011307/1, NE/K016253/1, NE/K016407/1, NE/K016148/1, NE/K0106261/1, NE/K015377/1, NE/L002515/1, NE/L002582/1 and NE/P00363X/1 and studentship 1122589; the Varley Gradwell Travelling Fellowship; and the World Wildlife Fund for Nature. Data collection was supported by R. Adzhar, A. Afendy, N. Arumugam, S. Benedick, V. Bignet, S. Butler, K. Graves, H. E. Hah, H. Heroin, A. Kendall, H. H. Mahsol, D. Mann, J. Miller, S. Milne, J. Mumford, D. Norman, H. Rossleykho, D. Shapiro, K. Sieving, J. Sugau, B. Udell, B. E. Yahya and M. A. Zakaria.Logged and disturbed forests are often viewed as degraded and depauperate environments compared with primary forest. However, they are dynamic ecosystems1 that provide refugia for large amounts of biodiversity2,3, so we cannot afford to underestimate their conservation value4. Here we present empirically defined thresholds for categorizing the conservation value of logged forests, using one of the most comprehensive assessments of taxon responses to habitat degradation in any tropical forest environment. We analysed the impact of logging intensity on the individual occurrence patterns of 1,681 taxa belonging to 86 taxonomic orders and 126 functional groups in Sabah, Malaysia. Our results demonstrate the existence of two conservation-relevant thresholds. First, lightly logged forests (68%) of their biomass removed, and these are likely to require more expensive measures to recover their biodiversity value. Overall, our data confirm that primary forests are irreplaceable5, but they also reinforce the message that logged forests retain considerable conservation value that should not be overlooked