arid and semi-arid areas, due to the sensitive, have variable ecosystems, so continuous assessment and monitoring of the environment is required for most of managerial and adjustment practices. vegetation is one of the most important assessment tools and used as a criterion for evaluation and monitoring of ecosystem functions. in this study, for the first time in the country, we have evaluated ...

The assembly of regional biotas and organismal responses to anthropogenic climate change both depend on the capacity of organisms to adapt to novel ecological conditions. Here we demonstrate the concept of evolutionary lag time, the time between when a climatic regime or habitat develops in a region and when it is colonized by a given clade. We analyzed the time of colonization of four clades (...

Rates and impacts of atmospheric nitrogen (N) deposition are poorly understood in arid land ecosystems where soils are typically low in plant available N. To address this issue, we quantified long-term trends in N deposition and estimated its impact on plant community structure in the northern Chihuahuan desert of Central New Mexico, USA. Annual and seasonal rates of N deposition were strongly ...

Drought and salt stress, together with low temperature, are major problems for agriculture because these adverse environmental factors prevent plants from realizing their full genetic potential. Salt stress afflicts agriculture in many parts of the world, particularly irrigated lands [4]. Compared to salt stress, the problem of drought is even more pervasive and economically damaging [1; 3]. Te...

The rapidly increasing incidence of diabetes mellitus is becoming a serious threat to mankind's health in all parts of the world. In fact, known cases reflect only part of the problem, as many diabetics, especially with type 2 diabetes, are unaware of their disease, which initially shows no definitive symptoms. Despite the great efforts invested in diabetes research, its prevalence continues to...

Regime shifts are abrupt transitions between alternate ecosystem states including desertification in arid regions due to drought or overgrazing. Regime shifts may be preceded by statistical anomalies such as increased autocorrelation, indicating declining resilience and warning of an impending shift. Tests for conditional heteroskedasticity, a type of clustered variance, have proven powerful le...

Rock varnish coats many surfaces of geomorphic and archaeologic interest in arid lands. All varnish dating techniques are limited by the time lag between the exposure of a surface to subaerial processes and the onset of varnishing. They are valid only where manganese is not remobilized after deposition, for example, in most arid environments. The premise of a new age-determination method, catio...

BACKGROUND Climate change scenarios that include precipitation shifts and nitrogen (N) deposition are impacting carbon (C) budgets in arid ecosystems. Roots constitute an important part of the C cycle, but it is still unclear which factors control root mass loss and nutrient release in arid lands. METHODOLOGY/PRINCIPAL FINDINGS Litterbags were used to investigate the decomposition rate and nu...

BACKGROUND Biological soil crusts are common components of desert ecosystem; they cover ground surface and interact with topsoil that contribute to desertification control and degraded land restoration in arid and semiarid regions. METHODOLOGY/PRINCIPAL FINDINGS To distinguish the changes in topsoil affected by biological soil crusts, we compared topsoil properties across three types of succe...

Vulnerability to water stress-induced cavitation was measured on 27 woody shrub species from three arid plant communities including chaparral, coastal sage and Mojave Desert scrub. Dry season native embolism and pre-dawn water potential, and both wet and dry season xylem specific hydraulic conductivity (Ks) were measured. Cavitation resistance, estimated as water potential at 50% loss in conduc...