AMPLI GAMMA - Landscape planning and gamma multi-diversity

Approaches

To provide an overview of the current state of knowledge on this issue, a systematic review of the relationship between landscape heterogeneity and biodiversity was conducted in accordance with current standards. The objectives of this review are as follows:

(1) to explore and analyze, based on the results of empirical field studies, the relationship between landscape heterogeneity and diversity (HD relationship), focusing on the nature of the relationship (positive, negative, bell-shaped curve);

(2) to analyze which factors in the study, whether methodological (e.g., quality of the sampling plan, sample size) or ecological (landscape context of the study, type of heterogeneity, level of biodiversity analyzed), can explain the variability of this relationship.

Results

Two successive sorting and extraction phases resulted in the selection of 159 references and 3,523 elementary results from the 2,605 references initially identified.

The studies were conducted mainly in four geographical contexts (% relative to the number of elementary results): Spain (19%), Europe (15%), France (13%), and Germany (12%). The ecosystems sampled were predominantly agricultural (72%), with the remaining cases covering multiple environments (14%), forests (8%), or aquatic environments (5%).

The taxonomic groups studied were mainly birds (22%), plants (17%), bees (14%), butterflies (8%), carabids (7%), hoverflies (3.1%) and mammals (2.3%), with other taxonomic groups (reptiles, amphibians, mollusks, fish, annelids, springtails, arachnids, bacteria, fungi, protists) each accounting for less than 1% of observations.

The HD relationship analyzed is very often insignificant (75.6%), with positive relationships (16.7%) being more frequent than negative relationships (5.6%). Bell-curve relationships (Hmax) are anecdotal (0.6%).

Additional data is currently being collected and further analysis will enable the initial results to be refined.

The results obtained so far are interesting and enable us to identify the main gaps in research on the HD relationship in terms of the taxonomic groups studied, the type of heterogeneity, the type of landscape sampled, and the geographical context.

The systematic review will make it possible to assess the extent to which recommendations to increase crop and agricultural practice heterogeneity at the landscape level (composition heterogeneity) and reduce plot size (configuration heterogeneity) can be transposed to other types of landscapes, particularly forests, aquatic environments, and mixed landscapes.

Participants

INRAE units involved

• UR LESSEM - Laboratoire écosystèmes et sociétés en montagne
• UMR BAGAP - Biodiversité, agroécologie et aménagement du paysage
• UMR DYNAFOR - Dynamiques et écologie des paysages agriforestiers
• UR EFNO - Unité de recherche Écosystèmes forestiers
• UR PSH - Unité de recherche Plantes et Systèmes de culture Horticoles
• UMR ABSYS - Agrosystèmes biodiversifiés
• UMR LISAH - Laboratoire d'étude des interactions Sol - Agrosystème - Hydrosystème
• UR EABX - Unité de recherche Écosystèmes aquatiques et changements globaux
• UREP - Unité de recherche Écosystème prairial
• UMR LISC - Lab of Engineering for Complex Systems
• UMR SAVE - Santé et agroécologie du vignoble 

Partners

• UMR Ecobio - Ecosystèmes, Biodiversité, Evolution - Université Rennes
• University of Jyväskylä (Finlande)