# Research needs on the biodiversity–ecosystem functioning relationship in drylands

## TL;DR

This paper identifies key research gaps in understanding how biodiversity affects ecosystem functioning in drylands, emphasizing the need for targeted studies to improve conservation and management strategies.

## Contribution

The paper outlines five specific research needs to advance understanding of biodiversity–ecosystem functioning relationships in dryland ecosystems.

## Key findings

- Biodiversity interactions with climate and soil properties in drylands are not fully understood.
- Intra-specific trait variability and biotic interactions are understudied aspects of the biodiversity–ecosystem functioning relationship.
- Temporal variability and human activities, such as grazing and urbanization, require further investigation in dryland ecosystems.

## Abstract

Research carried out in drylands over the last decade has provided major insights on the biodiversity–ecosystem functioning relationship (BEFr) and about how biodiversity interacts with other important factors, such as climate and soil properties, to determine ecosystem functioning and services. Despite this, there are important gaps in our understanding of the BEFr in drylands that should be addressed by future research. In this perspective we highlight some of these gaps, which include: 1) the need to study the BEFr in bare soils devoid of perennial vascular vegetation and biocrusts, a major feature of dryland ecosystems, 2) evaluating how intra-specific trait variability, a key but understudied facet of functional diversity, modulate the BEFr, 3) addressing the influence of biotic interactions on the BEFr, including plant–animal interactions and those between microorganisms associated to biocrusts, 4) studying how differences in species–area relationships and beta diversity are associated with ecosystem functioning, and 5) considering the role of temporal variability and human activities, both present and past, particularly those linked to land use (e.g., grazing) and urbanization. Tackling these gaps will not only advance our comprehension of the BEFr but will also bolster the effectiveness of management and ecological restoration strategies, crucial for safeguarding dryland ecosystems and the livelihoods of their inhabitants.