Abstract
Grasslands and savannas characterize much of the world's dryland ecosystems. Various lines of evidence indicate the grass/shrub balance in these systems has destabilized in the recent decades. Here, we link long-term field and remote sensing observations to quantify woody plant dynamics at a site in the southwestern USA where Prosopis velutina has proliferated in semi-desert grassland. Field records revealed that the overall trend can be dissected into three phases: Rapid expansion (1957-1991), abrupt decline (1991-1997) and stabilization (1997-2006). The contributions of land histories and topo-edaphic factors to the trend were complex. Remote sensing observations indicated net declines in woody cover since 1984. Some of these occurred at sites with recent fires, whereas others may reflect density dependent dynamics. Notable exceptions occurred at low elevations where cacti proliferated. This study confirms that temporal and spatial dynamics of woody cover change are not unidirectional and are influenced by complex combinations of factors.
| Original language | English (US) |
|---|---|
| State | Published - 2011 |
| Event | 34th International Symposium on Remote Sensing of Environment - The GEOSS Era: Towards Operational Environmental Monitoring - Sydney, NSW, Australia Duration: Apr 10 2011 → Apr 15 2011 |
Other
| Other | 34th International Symposium on Remote Sensing of Environment - The GEOSS Era: Towards Operational Environmental Monitoring |
|---|---|
| Country/Territory | Australia |
| City | Sydney, NSW |
| Period | 4/10/11 → 4/15/11 |
Keywords
- Arid environments
- Cacti
- Carbon sequestration
- Landsat
- Prosopis velutina
- Spectral mixture analysis
- Succulents
- Tree-grass interactions
ASJC Scopus subject areas
- Computer Networks and Communications
- Environmental Engineering