Write whether the following statements are true or false .
(i) Communities with more species tend to be more stable that those with less species.
(ii) David Tilman found that plots with less species showed less year-to-year variation in total biomass.
(iii) A stable community must be resistant to invasions by exotic species.
(iv) Effect of reduction in diversity has been explained by Alexander von Humboldt through rivet popper hypothesis.

Explanation

To determine whether the given statements are true or false, we will analyze each statement based on our understanding of biodiversity and ecological stability.

### Step-by-Step Solution:

1. **Statement (i)**: "Communities with more species tend to be more stable than those with less species."
- **Analysis**: It is widely accepted in ecology that greater biodiversity contributes to ecosystem stability. More species can lead to more complex interactions and resilience to disturbances.
- **Conclusion**: This statement is **True**.

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