Biodiversity Effects On Marine Macroalgal Communities.pdf

Boyer et al. (2009) investigated how biodiversity affects the productivity and stability of marine macroalgal communities, focusing on the role of environmental context. Key findings include:

1. Productivity:
- Nutrient addition promoted positive species richness effects on algal growth in one mesocosm experiment but weakened the relationship in another.
- Species richness increased algal biomass production at two out of four field sites.
- Net biodiversity effects were driven by positive complementarity (facilitation or complementary resource use) and negative selection effects, with no evidence of positive selection effects.

2. Mechanisms:
- Complementarity and selection effects varied in their influence on net biodiversity effects across different environmental conditions.

3. Stability:
- Species richness enhanced the stability of algal community biomass across various environmental settings in field experiments.

4. Environmental Context:
- Diversity effects on algal biomass production were strongly influenced by environmental conditions that vary over space and time.
- Other environmental factors, such as resources, drought, temperature, and herbivore richness, may also influence richness-production relationships.

5. Methodology:
- The study used mesocosm experiments with varying nutrient supply and a field experiment replicated at four sites to represent a range of estuarine conditions.
- Multiple response variables were measured to assess the influence of the metric used on diversity-function studies.