Short time series obscure compensatory dynamics in ecological communities

Area of Science:

• Ecology
• Community Ecology
• Ecological Stability

Background:

• Species synchrony, the coordinated fluctuations of species populations, is vital for ecological community stability.
• Quantifying species synchrony accurately typically requires extensive long-term observational data.
• Existing empirical studies often rely on limited short time series, potentially leading to biased conclusions.

Purpose of the Study:

• To investigate how the length of time series data influences the measurement and interpretation of species synchrony.
• To explore the impact of time series duration on the relationship between species synchrony, diversity, and competition.
• To reconcile discrepancies between theoretical predictions and empirical findings regarding species synchrony.

Main Methods:

• Combined spectral analysis, dynamical community modeling, and analysis of over 2,000 empirical plant community time series.
• Theoretical analyses explored the effects of competition on synchrony across different timescales.
• Model communities were used to simulate and analyze synchrony patterns under varying conditions.

Main Results:

• Species synchrony tends to decrease as time series length increases.
• Competition decreases synchrony over long timescales but increases it over short timescales.
• In model communities, synchrony decreased with diversity and competition in long time series but increased in short ones.

Conclusions:

• The length of observational time series critically affects the assessment of species synchrony and its relationship with species richness.
• Findings challenge the assumption that observational duration does not qualitatively alter ecological patterns.
• Results have significant implications for ecological sampling design and the interpretation of community dynamics.