Biology subjects

Grantham, H.

Publications and source records attributed to Grantham, H..

3 recordsLinked to original sources

bioRxiv2020

Myanmar's terrestrial ecosystems: status, threats and conservation opportunities

Myanmar is highly biodiverse, with more than 16,000 plant, 314 mammal, 1131 bird, 293 reptile, and 139 amphibian species. Supporting this biodiversity is a variety of natural ecosystems--mostly undescribed--including tropical and subtropical forests, savannas, seasonally inundated wetlands, extensive shoreline and tidal systems, and alpine ecosystems. Although Myanmar contains some of the largest intact natural ecosystems in Southeast Asia, remaining ecosystems are under threat from accelerating land use intensification and over-exploitation. In this period of rapid change, a systematic risk assessment is urgently needed to estimate the extent and magnitude of human impacts and identify ecosystems most at risk to help guide strategic conservation action. Here we provide the first comprehensive conservation assessment of Myanmars natural terrestrial ecosystems using the IUCN Red List of Ecosystems categories and criteria. We identified 64 ecosystem types for the assessment, and used models of ecosystem distributions and syntheses of existing data to estimate declines in distribution, range size, and functioning of each ecosystem. We found that more than a third (36.9%) of Myanmars area has been converted to anthropogenic ecosystems over the last 2-3 centuries, leaving nearly half of Myanmars ecosystems threatened (29 of 64 ecosystems). A quarter of Myanmars ecosystems were identified as Data Deficient, reflecting a paucity of studies and an urgency for future research. Our results show that, with nearly two-thirds of Myanmar still covered in natural ecosystems, there is a crucial opportunity to develop a comprehensive protected area network that sufficiently represents Myanmars terrestrial ecosystem diversity.

ecology↗

bioRxiv2020

Forest condition in the Congo Basin for the assessment of ecosystem conservation status

Measuring forest degradation is important for understanding and designing measures to protect biodiversity and the capacity of forests to deliver ecosystem services. Conservation planning, particularly the prioritization of management interventions for forests, is often lacking spatial data on ecological condition, and it is often overlooked within decision-making processes. Existing methods for assessing forest degradation via proxies or binary measures (i.e. intact or not) cannot adequately consider the important variations of ecological condition. Direct methods to measure degradation (e.g. through remote sensing) require extensive training data, calibration and validation, and may be too sensitive to small-scale or short-term changes which may not be related to degradation. We developed a metric termed Forest Condition (FC) which aims to measure the degree of forest degradation, incorporating temporal history of forest change over a large spatial extent. We parameterized this metric based on estimated changes in above ground biomass in the context of forest fragmentation over time to estimate a continuous measure of forest degradation for Congo Basin countries. We estimate that just less than 70% of Congo Basin forests remain fully intact. FC was validated by direct remote sensing measurements from Landsat imagery for DRC. Results showed that FC was significantly positively correlated with forest canopy cover, gap area per hectare, and magnitude of temporal change in Normalized Burn Ratio. We tested the ability of FC to distinguish primary and secondary degradation and deforestation and found significant differences in gap area and spectral anomalies to validate our theoretical model. We used the IUCN Red List of Ecosystems criteria to demonstrate the value of applying forest degradation to assess the risk of ecosystem collapse. Based on this assessment, we found that without including FC in the assessment of biotic disruption, 12 ecosystems could not have a threat status assigned, and a further 9 ecosystems would have a lower threat status. Our overall assessment of ecosystems found approximately half of forest of Congo Basin ecosystem types which cover over 20% of all forest area are threatened including 4 ecosystems (<1% of total area) which are critically engendered. FC is a transferrable and scalable assessment to support forest monitoring, planning, and management.

ecology↗

bioRxiv2019

Reconciling global priorities for conserving biodiversity habitat

Degradation and loss of natural habitat is the major driver of the current global biodiversity crisis. Most habitat conservation efforts to date have targeted small areas of highly threatened habitat, but emerging debate suggests retaining large intact natural systems may be just as important. We reconcile these perspectives by integrating fine-resolution global data on habitat condition and species assemblage turnover, to identify Earths high-value biodiversity habitat. These are areas in better condition than most other locations once supporting a similar assemblage of species, and are found within both intact regions and human dominated landscapes. However, only 18.6 % of this high-value habitat is currently protected globally. Averting permanent biodiversity loss requires clear spatially explicit targets for retaining these unprotected high-value habitats.

ecology↗