Question

A research team assesses the impact of the invasive species Lantana camara on the seed set of a native flowering plant S. The plant S usually grows in clumps with other individuals of the same or different flowering species. They measure the seed set of flowering individuals of S grown (i) alone; (ii) with a conspecific (same species); (iii) with a native species Q; (iv) with a native species R; (v) with Lantana camara. The figure below shows the mean seed set with 95% confidence intervals for the different treatments.Based on the figure provided, which one or more of the options given is/are correct?

• A. Seed set is higher in the presence of both the native species than in the presence of a conspecific.
• B. Seed set is lower in the presence of Lantana camara than in the presence of both the native species.
• C. Seed set is lower in the presence of Lantana camara than in the presence of a conspecific.
• D. Seed set is always higher in the presence of other plants than when grown alone.

Hint:

Many small patches can buffer system-wide risks (disease, fires, storms) via spatial separation, but they often raise local extinction risk; weigh metapopulation rescue and connectivity when designing reserves.

Answer 1

The Correct Option is C

Effect of Lantana camara on Seed Set

Step 1: Approximate means from the bar plot:

\[ \text{Alone} \approx 160, \quad \text{Conspecific} \approx 170, \quad \text{Native Q} \approx 90, \quad \text{Native R} \approx 250, \quad \textit{Lantana} \approx 80 \]

Step 2: Check each statement against the data.

(A) “Both native species > conspecific.” Native Q (≈90) is lower than conspecific (≈170). \(\Rightarrow\) False.

(B) “Lantana < both natives.” Lantana (≈80) is less than Native Q (≈90) and Native R (≈250). \(\Rightarrow\) True.

(C) “Lantana < conspecific.” Lantana (≈80) is clearly lower than conspecific (≈170). \(\Rightarrow\) True.

(D) “Always higher with other plants than alone.” With Native Q (≈90) and Lantana (≈80), seed set is lower than Alone (≈160). \(\Rightarrow\) False.

Final Answer: \[ \boxed{(B) \text{ and } (C)} \]