The conclusion of David Tilman regarding the biodiversity of organisms is

Options

A. Increased species diversity contributed to lower productivity
B. Decreased species diversity contributed to higher productivity
C. Increased species diversity contributed to higher productivity
D. Organisms in colder areas have shorter limbs

Answer

**Step-by-Step Text Solution:**

1. **Understanding David Tilman's Research**: David Tilman is a prominent ecologist known for his work on biodiversity and its impact on ecosystem productivity. He conducted experiments that showed the relationship between species diversity and ecosystem functioning.

2. **Key Conclusion**: Tilman's key conclusion is that increased biodiversity (the variety of species in a community) leads to higher productivity. This means that ecosystems with a greater number of different species tend to produce more biomass and have better overall functioning.

3. **Stable Communities**: He also noted that stable communities do not exhibit excessive variations in productivity. A stable ecosystem maintains consistent productivity levels over time, which is crucial for its sustainability.

4. **Evaluating Options**: When presented with various options regarding Tilman's conclusions:
- The first option states that increased species diversity contributes to lower productivity. This contradicts Tilman's findings.
- The second option suggests that decreased species diversity contributes to higher productivity. This is also incorrect according to Tilman's research.
- The third option claims that increased species diversity contributes to higher productivity. This aligns perfectly with Tilman's conclusions and is the correct answer.
- The last option about organisms in colder areas having shorter limbs is unrelated to Tilman's conclusions on biodiversity and productivity.

5. **Final Answer**: The correct conclusion drawn from David Tilman's research is that "increased species diversity contributes to higher productivity."

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