|Author(s)||Almoussawi Ali1, 2, Lenoir Jonathan1, Jamoneau Aurélien1, 3, Hattab Tarek1, 4, Wasof Safaa1, 5, Gallet‐moron Emilie1, Garzon‐lopez Carol X.1, 6, Spicher Fabien1, Kobaissi Ahmad2, Decocq Guillaume1, Collins Beverly|
|Affiliation(s)||1 : Unité de Recherche “Ecologie et Dynamique des Systèmes Anthropisés” EDYSAN UMR CNRS 7058 , Université de Picardie Jules Verne Amiens ,France
2 : Applied Plant Biotechnology Laboratory Life and Earth Sciences Department Faculty of Sciences Lebanese University Beirut ,Lebanon
3 : Aquatic Ecosystems and Global Changes Research Unit, IRSTEA ,Cestas ,France
4 : UMR MARBEC ,Institut Français de Recherche pour l’Exploitation de la Mer Sète ,France
5 : Department of Environment, Forest & Nature Lab (ForNaLab) Ghent University ,Melle‐Gontrode ,Belgium
6 : Ecology and Plant Physiology group (Ecofiv), Universidad de los Andes Bogotá, Colombia
|Source||Journal Of Vegetation Science (1100-9233) (Wiley), 2020-01 , Vol. 31 , N. 1 , P. 63-74|
|WOS© Times Cited||2|
|Note||This study was part of the METAFOR research project funded by the Conseil Régional de Picardie.|
|Keyword(s)||agricultural landscapes, alpha diversity, anthropogenic disturbances, community assembly, dispersal limitations, gamma diversity, habitat conservation strategies, habitat fragmentation, local-regional richness relationship, metacommunity dynamics|
Forest fragmentation affects biodiversity locally (α diversity) and beyond — at relatively larger scales (γ diversity) — by increasing dispersal and recruitment limitations. Yet, does an increase in fragmentation affect the relationship between α and γ diversity and what can we learn from it?
We surveyed 116 forest patches across three fragmentation levels: none (continuous forest); intermediate (forest patches connected by hedgerows); and high (isolated forest patches). Plant species richness of both forest specialists and generalists was surveyed at five nested spatial resolutions across each forest patch: 1 m2; 10 m2; 100 m2; 1,000 m2; and total forest patch area. First, we ran log‐ratio models to quantify the α–γ relationship. We did that separately for all possible combinations of fragmentation level (none vs intermediate vs high) × spatial scale (e.g., α‐1 m2 vs γ‐10 m2) × species type (e.g., α‐specialists vs γ‐specialists). We then used linear mixed‐effects models to analyze the effect of fragmentation level, spatial scale, species type and all two‐way interaction terms on the slope coefficient extracted from all log‐ratio models.
We found an interaction effect between fragmentation level and species type, such that forest specialists shifted from a linear (i.e., proportional sampling) to a curvilinear plateau (i.e., community saturation) relationship at low and high fragmentation, respectively, while generalists shifted from a curvilinear to a linear pattern.
The impact of forest fragmentation on the α–γ relationship supports generalist species persistence over forest specialists, with contrasting mechanisms for these two guilds. As fragmentation increases, forest specialists shift from proportional sampling towards community saturation, thus reducing α diversity likely due to dispersal limitation. Contrariwise, generalists shift from community saturation towards proportional sampling, thus increasing α diversity likely due to an increase in the edge:core ratio. To ensure long‐term conservation of forest specialists, one single large forest patch should be preferred over several small ones.
Almoussawi Ali, Lenoir Jonathan, Jamoneau Aurélien, Hattab Tarek, Wasof Safaa, Gallet‐moron Emilie, Garzon‐lopez Carol X., Spicher Fabien, Kobaissi Ahmad, Decocq Guillaume, Collins Beverly (2020). Forest fragmentation shapes the alpha–gamma relationship in plant diversity. Journal Of Vegetation Science, 31(1), 63-74. Publisher's official version : https://doi.org/10.1111/jvs.12817 , Open Access version : https://archimer.ifremer.fr/doc/00592/70438/