How do tropical forests change by the artificial factors, when they are in deforestation stage or restoration stage? Do the forest functions and spatial structures recover, as well as the area of tropical forests? The purpose of this project is to analyse and discuss these questions to a certain degree.
Tropical forest being as an important ecosystem plays a significant role in human life, environment sustainability, biodiversity, climate changes. Study on change laws and the recovery processes of forests function and spatial structure can help us to know more about their attributes and intrinsic mechanisms which can assist policy-makers and managers.
This project collected land cover data between 1960 and 2010 (the years for 1960, 1979, 1986, 2000, 2005, 2010, six data groups) in Guanacaste, Costa Rica, from land use map and remote sensing images. According to Holdridge Life Zone Classification System [1], forests could be separated into four types: tropical rain forests, tropical wet forests, tropical humid forests and tropical dry forests. So, every data group was divided into four subsets. Finally I got 24 data subsets, and calculated landscape indices for individual subset in both patch-level and class-level.
The objectives of this project aimed to analyse the overall trend of forest changes, to discuss the changes of forest patches in order to watch the recovery of forest function and spatial structure, and to analyse the similarities of forests in the view of patches when the forests were in deforestation stage or restoration stage.
Research shows that the process of all forests change can be separated into two stages during these 50 years: deforestation stage and restoration stage. Forests began to degrade from 1960 and to recover in the mid of 1980s. When I analysed forest patches, an interesting result was found out: although the forest rose up to the original state, s forest function and spatial structure did not fully recover. In the end, all forests were clustered into 4 groups according to the similarities of spatial pattern and structure.