This week we learn about the importance of spatial analysis on understanding landscape ecology. We first review the definition of landscape ecology, which concerned with the mutual interaction between spatial pattern and ecological processes that occur on landscapes. Landscape pattern and process are two essential things in landscape ecology. The process can cause landscape patterns, in return, the patterns can modify processes. As spatial analysists, our goal is to examine the variability and the causations of variability among locations.
The processes may happen under several conditions., a. Including abiotic conditions such as climate change and topography, b. Biotic factors such as competition, c. Human activity, d. Disturbance processes such as fires, volcanic eruptions, floods, and storms. The landscape pattern showing today is a reflection of multiple processes operating at different temporal and spatial scales.
Patterns only develop if the objects exhibit spatial autocorrelation. There are two types of spatial autocorrelation: a. First-Order process: the patterns emerge as a result of a response to an environmental factor. b. second-order process: if the patterns develop as a result of interactions between the objects themselves
A process is considered stationary if the processes that govern the placement of an object do not change over space. a. First-order stationarity: if there is no variation in the intensity over space b. Second-Order stationarity: if there is no interaction between objects. Stationarity also assumes that the process does not exhibit a directional bias such as isotropic pattern, while the anisotropic patterns indicate the process does show a directional bias.
In the end, we learned some vital landscape metrics:
- Metrics of landscape composition: what is present for the objects themselves, without reference to where they are located (proportion occupied, relative richness, diversity and dominance, connectivity)
- Measures of spatial configuration: about the landscape and location (probabilities of adjacency, contagion, patch area, and perimeter, connectivity, proximity index, area-weighted average patch size)
- Fractals; the spatial complexity