Land Use Impacts on Local and Regional Freshwater Biodiversity Can Compromise Current Management Goals

Area of Science:

• Ecology
• Environmental Science
• Conservation Biology

Background:

• Freshwater ecosystems and biodiversity are globally threatened by land use and anthropogenic activities.
• Existing long-term monitoring data offer limited insight into freshwater biodiversity changes and the efficacy of current environmental targets.

Purpose of the Study:

• To investigate the impact of land use on freshwater biodiversity in Finland using nationwide survey data.
• To evaluate the effectiveness of the 'good ecological status' class in protecting freshwater biodiversity.

Main Methods:

• Utilized nationwide survey data for stream and lake diatoms, macroinvertebrates, and macrophytes.
• Employed RIVPACS-type multitaxon distribution models with independent validation to assess biodiversity metrics (O/E ratios, taxon prevalence).

Main Results:

• Land use negatively affected local diversity in stream communities and, to a lesser extent, lake communities (particularly impacted by agriculture).
• Regional taxon prevalence decreased significantly across various groups (diatoms, macrophytes, macroinvertebrates) in response to land use.
• Shifts in species composition were observed, with sensitive species declining and tolerant species increasing, especially in agricultural areas. The 'good ecological status' classification showed insufficient protection for some taxa, like stream macroinvertebrates.

Conclusions:

• Land use significantly alters freshwater biodiversity at both local and regional scales.
• The current 'good ecological status' framework may not adequately protect freshwater biodiversity, highlighting a need for revised environmental objectives.
• Integrating freshwater biodiversity considerations into environmental goals is crucial for effective conservation and restoration strategies.