Choosing the Best Ant Diversity Sampling Strategy
The researcher aims to study ant diversity across a landscape containing two distinct habitats: riverine valleys and plateaus. The goal is to select the most effective sampling strategy to accurately represent and compare diversity across these areas.
Evaluating Sampling Approaches
The most appropriate method involves stratified sampling, where the landscape is divided into distinct strata (the habitats) and sampling occurs within each. For comparing diversity across these strata, the allocation of sampling effort (e.g., number of quadrats) is crucial.
- Option 4 (Proportional Allocation): Laying quadrats in both habitats in proportion to their respective areas is a form of stratified random sampling with proportional allocation. This strategy ensures that larger habitats contribute more to the sample, reflecting their actual contribution to the landscape. It provides a more accurate and less biased estimate of overall diversity and allows for meaningful comparisons between habitats, even if they differ significantly in size.
- Option 2 (Equal Allocation): Laying an equal number of quadrats in valleys and plateaus ignores the potential differences in habitat size. If one habitat is much larger than the other, this method could lead to over-sampling the smaller habitat and under-sampling the larger one, skewing the diversity estimates.
- Option 1 (Opportunistic Sampling): Laying quadrats only after an ant is located is opportunistic. This approach is unlikely to capture the full range of species or adequately sample different microhabitats within the valleys and plateaus.
- Option 3 (Focusing on Abundance): Laying quadrats only in areas of high ant abundance focuses on richness or density in specific spots but may miss less common species or species adapted to areas with lower abundance, failing to provide a comprehensive diversity picture across the entire landscape.
Therefore, sampling in proportion to habitat area ensures better representation and is the most robust strategy for comparing diversity across heterogeneous landscapes.
Important Questions from Sampling Theorems
In the construction of cost of living index, commodities are selected by:
If 4, 5, 6, 6, 6, 6, 6, 6, 6, 7 be a random sample from a Poisson population with parameter λ, then an unbiased estimate of λ is:
The data taken from the publication "sankhya" will be considered as:
A completely randomised design is based on the principles of ______ and randomisation only.
A sample of 30 latest returns on UTI stock reveals a mean return of $4 with a sample standard deviation of $0.13. The estimated standard error of the sample mean is:
