Ap Environmental Science Calculator

AP Environmental Science: Biodiversity Calculator

This calculator helps you estimate the biodiversity of an ecosystem based on species richness and evenness. Biodiversity is a crucial concept in AP Environmental Science, representing the variety of life in a particular habitat or ecosystem. Higher biodiversity generally indicates a healthier and more resilient ecosystem.

Understanding Biodiversity Metrics

Species Richness: This is the simplest measure of biodiversity and refers to the total number of different species present in a given area. A higher species richness usually implies a more diverse ecosystem.

Total Number of Individuals: This is the sum of all individual organisms across all species in the area. It's a key component in understanding species abundance.

Shannon Evenness Index (E_H): This index measures how close in numbers each species in an environment is. An evenness of 1 means all species have equal populations, while an evenness close to 0 indicates that a few species dominate in number. The Shannon Index itself (H') is calculated as $H' = -\sum_{i=1}^{S} p_i \ln(p_i)$, where $S$ is the species richness and $p_i$ is the proportion of individuals belonging to species $i$. The Shannon Evenness is then calculated as $E_H = H' / \ln(S)$.

For this calculator, we will provide an estimate. If you provide the Shannon Evenness, the result will be more nuanced. If not, we will focus on species richness as a primary indicator.

function calculateBiodiversity() { var richness = parseFloat(document.getElementById("speciesRichness").value); var totalIndividuals = parseFloat(document.getElementById("totalIndividuals").value); var evenness = parseFloat(document.getElementById("shannonEvenness").value); var resultDiv = document.getElementById("result"); resultDiv.innerHTML = ""; // Clear previous results if (isNaN(richness) || isNaN(totalIndividuals) || richness <= 0 || totalIndividuals = 0 && evenness <= 1) { // If evenness is provided, we can give a more sophisticated interpretation. // For simplicity in this example, we'll present richness and evenness. // A full Shannon Index calculation would require individual species counts. biodiversityMetric = "

Biodiversity Estimate:

"; biodiversityMetric += "Species Richness: " + richness + ""; biodiversityMetric += "Shannon Evenness: " + evenness.toFixed(2) + ""; if (evenness > 0.7) { biodiversityMetric += "This ecosystem exhibits high evenness, suggesting a stable community where different species are well-represented."; } else if (evenness > 0.4) { biodiversityMetric += "This ecosystem has moderate evenness. Some species are more dominant than others."; } else { biodiversityMetric += "This ecosystem has low evenness, indicating that a few species are highly abundant while many others are rare."; } } else { // If evenness is not provided or invalid, focus on richness. biodiversityMetric = "

Biodiversity Estimate:

"; biodiversityMetric += "Species Richness: " + richness + ""; biodiversityMetric += "With " + richness + " species, this ecosystem appears to have a moderate level of biodiversity. Higher richness generally correlates with greater ecosystem stability and resilience."; } resultDiv.innerHTML = biodiversityMetric; }