ORCID Profile
0000-0002-4241-1284
Current Organisation
Wageningen University & Research
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Publisher: Wiley
Date: 06-08-2022
DOI: 10.1111/DDI.13596
Abstract: In coastal marine systems, biogenic reef‐building species have great importance for conservation as they provide habitat for a wide range of species, promoting bio ersity, ecosystem functioning and services. Biogenic reef persistence and recovery from perturbations depend on recolonization by new recruits. Characterizing larval dispersal among distant reefs is key to understanding how connectivity shapes metapopulation structure and determines network coherence all of which are of critical importance for effective conservation. Northeast Atlantic coast and western English Channel, France. We used a biophysical transport model to simulate larval dispersal of the reef‐building polychaete Sabellaria alveolata . We combined dispersal modelling and network analysis into a framework aiming to identify key reef areas and critical dispersal pathways, whose presence in the network is vital to its overall coherence. We evaluated changes in dispersal pathways constrained by different connectivity thresholds, i.e., minimum dispersal rate for the presence of a connection. We tested scenarios of sequential loss of reefs: randomly, by habitat quality (a score for reef status and occupancy in an area) or by betweenness centrality metric ( BC quantifying the proportion of shortest paths connecting all areas that are passing through any given area). We found that the network of S. alveolata reefs forms two main regional clusters, the Atlantic coast and the English Channel, which are connected only through weak sporadic dispersal events. Within each cluster, the network is characterized by relatively high connectivity among neighbouring areas with reefs, maintained even under higher connectivity thresholds. Simulating scenarios of sequential loss of reefs further identified high centrality reefs, those with highest BC values, key to network coherence. Effective conservation of this important reef habitat requires a network of protected areas designed to sustain a combination of locally important source reefs, and those that act as stepping stones connecting distant reefs.
Publisher: Wiley
Date: 02-02-2021
DOI: 10.1111/DDI.13224
Abstract: To investigate some of the environmental variables underpinning the past and present distribution of an ecosystem engineer near its poleward range edge. locations spanning ,400 km around Ireland. We collated past and present distribution records on a known climate change indicator, the reef‐forming worm Sabellaria alveolata (Linnaeus, 1767) in a biogeographic boundary region over 182 years (1836–2018). This included repeat s ling of 60 locations in the cooler 1950s and again in the warmer 2000s and 2010s. Using species distribution modelling, we identified some of the environmental drivers that likely underpin S. alveolata distribution towards the leading edge of its biogeographical range in Ireland. Through plotting 981 records of presence and absence, we revealed a discontinuous distribution with discretely bounded sub‐populations, and edges that coincide with the locations of tidal fronts. Repeat surveys of 60 locations across three time periods showed evidence of population increases, declines, local extirpation and recolonization events within the range, but no evidence of extensions beyond the previously identified distribution limits, despite decades of warming. At a regional scale, populations were relatively stable through time, but local populations in the cold Irish Sea appear highly dynamic and vulnerable to local extirpation risk. Contemporary distribution data (2013–2018) computed with modelled environmental data identified specific niche requirements which can explain the many distribution gaps, namely wave height, tidal litude, stratification index, then substrate type. In the face of climate warming, such specific niche requirements can create environmental barriers that may prevent species from extending beyond their leading edges. These boundaries may limit a species’ capacity to redistribute in response to global environmental change.
Location: United States of America
Location: Germany
No related grants have been discovered for Carmen L David.