(eds M.C.S. Wopereis et al.) 35 Upland environments are situated at the high end of the toposequence, where rice depends solely on rainfall as the water table is out of the reach of rice roots for much of the growing season. At the lower end of the toposequence, rice plants can reach the water table or profit directly from flood water. Along the toposequence, interactions exist between environm...

Most environmental modelling takes place within the toposequence. Conventionally, the terrain variables for these purposes have been derived from digital elevation models (DEMs) produced from large scale topographic maps (e.g. 1:25,000 (approx 30 meters)) or topographic data at that scale. Coverage in Australia of this scale DEM is very limited. However, global and continental coverage of DEMs ...

The model presented in this paper derives toposequences from a digital elevation model (DEM). It is written in ArcInfo Macro Language (AML). The toposequences are called kth-order random toposequences, because they take a random path uphill to the top of a hill and downhill to a stream or valley bottom from a randomly selected seed point, and they are located in a streamshed of order k accordin...

Remote sensing has become a valuable tool in monitoring arctic environments. The aim of this paper is ground-based hyperspectral characterization of Low Arctic Alaskan tundra communities along four environmental gradients (regional climate, soil pH, toposequence, and soil moisture) that all vary in ground cover, biomass, and dominating plant communities. Field spectroscopy in connection with ve...

Natural gamma-emitting radionuclides (U, Ra, Th, Pb) and selected major and trace elements (Ca, K, Mg, Na, Fe, Al, Mn, Pb, Ba, Zn, Sr, Li, Co, Ni, Cu, Cr, Cd) were determined in a soil toposequence along a mountain slope of the Tertiary Flysch landscapes in the Central Spanish Pyrenees. A variety of basic properties were also measured from the soil profiles. Mean radioisotope activities (Bq kg ...

The target basins of this project are located in the Mekong River Basin across the toposequence (northern Thailand, northeast Thailand, Mekong Delta in Vietnam). An additional site is located in Bhutan. In these basins, diverse stakeholders with differing perceptions of water dynamics adopt various strategies to cope with the problems. There is a need, therefore, to understand the factors influ...

Unprecedented rates of climate warming over the past century have resulted in increased forest stress and mortality worldwide. Decreased tree growth in association with increasing temperatures is generally accepted as a signal of temperature-induced drought stress. However, variations in tree growth alone do not reveal the physiological mechanisms behind recent changes in tree growth. Examining...