We tested the accuracy of an atmospheric correction method that depends on clear water bodies to infer solar and atmospheric parameters for radiative transfer equations by measuring the reflectance signature of four prominent south Texas rangeland plants with the Earth Resource Technology (LANDSAT) satellite multispectral scanner (MSS) and a ground-based Exotech Model 20 spectroradiometer. The ...

Global warming is projected to continue, leading to intense fluctuations in precipitation and heat waves and thereby affecting the productivity and the relevant biological processes of grassland ecosystems. Here, we determined the functional responses to warming and altered precipitation in both typical and desert steppes. The results showed that watering markedly increased the aboveground net ...

The genetic diversity found in domestic breeds allows farmers to develop new characteristics in response to changes in the environment, the appearance of diseases, or of modifications in market conditions. Indigenous breeds often possess gene combinations and special adaptations (such as disease resistance, adaptation to harsh conditions or poor-quality feeds) not found in other breeds. Five Ro...

— This paper contributes to the debate over land tenure in rural China by extending its spatial coverage to the country’s extensive rangeland regions. Key characteristics of pastoral tenure, identified from field appraisals in western China, include group tenure and fuzzy boundaries. Although these characteristics give rise to efficiency concerns, from a new institutional economics perspective ...

Rangeland ecosystems typify physical systems having an incomplete causal theory. This paper describes CARMA, a system for rangeland pest management advising that uses model-based matching and adaptation to integrate case-based reasoning with modelbased reasoning for prediction in rangeland ecosystems. An ablation study showed that removing any part of the CARMA’s model-based knowledge dramatica...

At the last deglaciation Earth’s largest biome, mammoth-steppe, vanished. Without knowledge of the productivity of this ecosystem, the evolution of man and the glacialeinterglacial dynamics of carbon storage in Earth’s main carbon reservoirs cannot be fully understood. Analyzes of fossils 14C dates and reconstruction of mammoth steppe climatic envelope indicated that changing climate wasn’t a r...

Knowledge of food resource of the houbara which an endangered species would be a important step toward the preservation of this bird. Adequate study has not been done in this field and therefore the food sources of the houbara during the brooding season was studied in the central steppe of Iran. In order to determine the density of insect in plant communities the pitfall trap was used , positio...

Aims Ecosystem carbon models often require accurate net ecosystem exchange of CO2 (NEE) light-response parameters, which can be derived from the Michaelis–Menten equation. These parameters include maximum net ecosystem exchange (NEEmax), apparent quantum use efficiency (a) and daytime ecosystem respiration rate (Re). However, little is known about the effects of land conversion between steppe a...

biodiversity plays a crucial role in stability and productivity of natural ecosystem. the main goal of this research was to classify ecological groups in steppe rangeland and investigate their relationships with plant diversity indices. therefore, fifty different land unit tracts (lut) were identified in khod-neuk basin, yazd province, iran, in 2010. vegetation and soil samples were taken in th...

This study describes the components of available forage in Vahregan watershed, Central Iran and highlight issues relating to forage endowment and environmental dynamics. In this study, proper use factor and palatability models and their components use to develop the model of available forage and measure it. The components climatic, topography, land systems, vegetation, land use and grass and sh...