Biology subjects

Oehri, J.

Publications and source records attributed to Oehri, J..

3 recordsLinked to original sources

bioRxiv2023

Rapid evaluation of habitat connectivity change to safeguard multispecies persistence in human-transformed landscapes

Protecting habitat connectivity in fragmented landscapes is essential for safeguarding biodiversity and natures contributions to people. Following the Post-2020 Kunming-Montreal Global Biodiversity Framework (KM-GBF) of the Convention on Biological Diversity (CBD) there is a clear science-policy need to assess habitat connectivity and track its change over time to inform conservation planning. In response to this need we describe an analytical, multi-indicator and multispecies approach for the rapid assessment of habitat connectivity at fine spatial grain and at the extent of an entire ecoregion. Out of 69 connectivity indicators we found through a literature review, we identified a key-set of nine indicators that align with the Essential Biodiversity Variables framework and that are suitable to guide rapid action for connectivity and conservation targets in the KM-GBF. Using these selected indicators, we mapped and evaluated connectivity change from 2011 to 2021 across the ecoregion of the St-Lawrence Lowlands in Quebec ([~]30,000 km2) for seven ecoprofile species representing regional forest habitat needs. For the majority of these ecoprofile species, trends over the last decade indicate a decline in effective connected area and metapopulation carrying capacity, mainly via a division of large contiguous habitat into smaller fragments, whereas total habitat area largely remained unchanged. These results highlight that trends in habitat area and connectivity are not necessarily correlated and the urgent need to conserve and restore connectivity in the St-Lawrence Lowlands, in order to meet regional targets under the KM-GBF. Our general approach enables a comprehensive evaluation of connectivity for regional spatial planning for biodiversity. We develop an R-tool to support this analysis and that can be extended to other conservation planning efforts for connectivity.

ecology↗

bioRxiv2022

Mid-summer snow-free albedo across the Arctic tundra was mostly stable or increased over the past two decades

Arctic vegetation changes, such as increasing shrub-cover, are expected to accelerate climate warming through increased absorption of incoming radiation and corresponding decrease in summer shortwave albedo. Here we analyze mid-summer shortwave land-surface albedo and its change across the pan-Arctic region based on MODIS satellite observations over the past two decades (2000-2021). In contrast to expectations, we show that terrestrial mid-summer shortwave albedo has not significantly changed in 82% of the pan-Arctic region, while 14% show an increase and 4% a decrease. By analyzing the visible and near-/shortwave-infrared range separately, we demonstrate that the slight increase arises from an albedo increase in the near-/shortwave-infrared range domain while being partly compensated by a decrease in visible albedo. A similar response was found across different tundra vegetation types. We argue that this increase in reflectance is typical with increasing biomass as a result of increased multiple reflection in the canopy. However, CMIP6 global climate model albedo predictions showed the opposite sign and different spatial patterns of snow-free summer albedo change compared to satellite-derived results. We suggest that a more sophisticated vegetation parametrization can reduce this discrepancy, and provide albedo estimates per vegetation type.

ecology↗

bioRxiv2021

Will Current Protected Areas Harbour Refugia for Threatened Arctic Vegetation Types until 2050? A First Assessment

Arctic vegetation is crucial for fauna and the livelihoods of Northern peoples, and tightly linked to climate, permafrost soils, and water. Yet, a comprehensive understanding of climate change effects on Arctic vegetation is lacking. Protected areas cannot halt climate change, but could reduce future pressure from additional drivers, such as land use change and local industrial pollution. Therefore, it is crucial to understand the contribution of protected areas in safeguarding threatened Arctic vegetation types. We compare the 2003 baseline with existing 2050 predictions of circumpolar Arctic vegetation type distributions and demonstrate an overrepresentation of dominant and underrepresentation of declining vegetation types within protected areas. According to IUCN criteria, five of eight assessed vegetation types were classified as threatened by 2050. Potential climate change refugia, areas with the highest potential for safeguarding threatened vegetation types, were also identified. This study provides an essential first step to assessing vegetation type vulnerability based on predictions covering 46% of Arctic landscapes. The co-development of new protective measures by policymakers and indigenous peoples at a pan-Arctic scale requires more robust and spatially complete vegetation prediction, as increasing pressures from resource exploration and infrastructure development threaten the sustainable development of the rapidly thawing and greening Arctic.

ecology↗