9 research outputs found
Recommended from our members
A qualitative spatial model of hardwood rangeland state- and-transition dynamics
We present a method for computerizing the transition rules of a state-and-transition model and then linking this model to a geographic information system. The resulting simulation characterizes rangeland vegetation dynamics in space and time. The method makes use of an expert system, a computer program that forms logical chains of transition rules. Simulation using state-and-transition rules, sometimes called qualitative simulation, has the disadvantage that it is less precise than traditional numerical simulation. However, it may have the advantage of being able to generate more robust simulation of complex vegetation communities. We demonstrate the application of the method by constructing a model of hardwood rangeland in the western foothills of the Sierra Nevada. The model is tested by comparison with historic black-and-white aerial photographs. The model is found to agree generally with the observed data but to differ substantially in some locations. Implications of this difference are discussed.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202
Physiology vs. environment: what drives oviposition decisions in mango fruit flies ( Bactrocera invadens
Monitoring habitat dynamics for rare and endangered species using satellite images and niche-based models
Assessing large spatial scale landscape change effects on water quality and quantity response in the lower Athabasca River basin
Data from: Biogeographic and anthropogenic correlates of Aleutian Islands plant diversity: a machine-learning approach
This is the first comprehensive analysis of vascular plant diversity patterns in the Aleutian Islands to identify and quantify the impact of Aleutian Island distance dispersal barriers, geographical, ecological and anthropogenic factors. Data from public Open Access databases, printed floristic accounts, and from collections made by the primary author were used to develop an Aleutian floristic database. The most common plant distribution pattern was ‘an eastern origin community’, though it compared similarly to the ‘Western’ and ‘Widespread’ distribution pattern. We established an ecological plant community composition class for each island, based on clustering species assemblage dissimilarity measurements (Jaccard Index), and a measurement of phylogenetic dissimilarity (UniFrac). We modelled these composition classes and species richness values in non-parametric algorithmic models and concepts (data cloning using machine learning, stochastic boosting- TreeNet,) based on classic and Aleutians-specific island biogeography hypotheses. Plant species richness is strongly associated with the equilibrium model variables of area and island isolation, as well as distance to the Alaska Peninsula, and island total stream length. Species composition is strongly associated with the landmass groups during the last glacial maximum, maximum island elevation, island isolation and island area. Phylogenetic composition is associated with island area, distance from the islands to the Chukotka Peninsula, maximum island elevation, island geologic age, and island isolation. This study extends the equilibrium theory of island biogeography by including additional drivers of diversity during the Anthropocene, such as the landmass during the LGM, as well as factors that may be related to anthropogenic extinction rate