Understanding Species Accumulation Curves in Urban Ecology…

What is a Species Accumulation Curve?

A species accumulation curve (SAC) is a graphical representation of how the number of observed species increases with sampling effort. In an urban bioblitz, this means tracking the number of different species discovered as more volunteers survey the park.

The SAC provides insights into the biodiversity of a habitat and can help predict the total number of species that might be present if further surveys were conducted.

Why Does It Matter?

Understanding SACs is crucial for conservation efforts, as it allows ecologists to estimate the true richness of a habitat and identify areas with high biodiversity. This information can guide resource allocation and policy decisions.

In urban settings, SACs help in assessing the impact of development on local ecosystems and planning green spaces that support diverse species.

live demo · related simulation● LIVE

The Chao1 Estimator

The Chao1 estimator is a statistical tool used to predict the total number of species in a sample based on the observed species richness and the abundance distribution. It helps fill in gaps where not all species have been discovered yet.

By applying the Chao1 estimator, researchers can make more accurate predictions about the true diversity of an area, even when sampling is limited.

Real-World Applications

In urban bioblitzes, SACs and the Chao1 estimator are used to assess biodiversity in fragmented habitats. For example, they can help identify which areas of a city park support the most species and inform decisions about where to create new green spaces.

These tools also play a role in monitoring the effects of climate change on urban ecosystems by tracking changes in species richness over time.

Frequently asked questions

How does habitat patchiness affect the species accumulation curve?

Habitat patchiness can lead to lower initial slopes and more variability in the SAC, as species may be concentrated in certain areas of the park, making it harder to discover them early on.

What is the rarity skew parameter in this simulation, and how does it influence the SAC?

The rarity skew parameter controls the distribution of species abundances. A higher skew means a few species are very common while many others are rare, which can result in a more complex SAC with multiple plateaus.

Can the Chao1 estimator be used for other types of ecological surveys besides bioblitzes?

Yes, the Chao1 estimator is widely applicable to any ecological survey where species richness needs to be estimated from a sample, including marine biodiversity studies and forest inventories.

How does increasing the number of volunteer surveyors affect the SAC in an urban bioblitz?

Increasing the number of volunteer surveyors typically leads to a faster increase in observed species richness, as more areas are surveyed and more species are likely to be discovered.

Try it live

Everything above runs in your browser — open Urban Bioblitz 2D: Species Accumulation Curve and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.

▶ Open Urban Bioblitz 2D: Species Accumulation Curve simulation