Dwarf shrubs of the family Ericaceae are common in arctic and alpine regions. Many of these plants are associated with ericoid mycorrhizal (ERM) fungi, which allow them to take nutrients and water from the soil under harsh environmental conditions and, thus, affect host plant survival. Despite the importance of ERM fungi to alpine plant communities, limited information is available on the effec...

grassland and not going anywhere are no longer cowpaths. The photograph shows the currently used paths in the grassland bowed toward the lower left by encroaching shrubs while faint scars above reveal where the paths once passed. In the grassland these old paths are obliterated by grass; in the shrub zone they remain bare and become broader. The great broad white zones of bare ground both insid...

Xylem water potential of the midelevation conifers Pinus jeffreyi, Pinus lambertiana, Abies concolor, and Calocedrus decurrens, the higher elevation Pinus monticola and Abies magnifica, and co-occurring evergreen angiosperm shrubs, together with soil moisture under these plants, were monitored at three sites on the Kern Plateau in the southernmost Sierra Nevada Range of California. Site locatio...

The integration of food production and biodiversity conservation represents a key challenge for sustainability. Several studies suggest that even small structural elements in the landscape can make a substantial contribution to the overall biodiversity value of the agricultural landscapes. Pastures can have high biodiversity potential. However, their intensive and monofunctional use typically e...

In karst ecosystems, a high level of CaCO3 enhances the stabilization of soil organic matter (SOM) and causes nitrogen (N) and/or phosphorus (P) limitation in plants. Oxalic acid has been suggested to be involved in the nutrient-acquisition strategy of plants because its addition can temporarily relieve nutrient limitation. Therefore, understanding how oxalic acid drives N availability may help...

Shrubs have positive (facilitation) and negative (competition) effects on understory plants, the net interaction effect being modulated by abiotic conditions. Overall shrubs influence to great extent the structure of plant communities where they have significant presence. Interactions in a plant community are quite diverse but little is known about their variability and effects at community lev...

the high quality and quantity seed production in old saxual shrubs are essential for regeneration and sustainable development of saxual forests in desert areas. the objective of this study was to determine the effects of different pruning height on saxual seed production. the study was carried out in an obviously wilted saxual forest located in ashkezar desert in yazd in 1994. the experiment wa...

Deserts are increasing in extent globally, but existing deserts are decreasing in health. The basic biology and ecology of foundation plant species in deserts are limited. This is a direct study that provides an estimate of the capacity for a locally dominant foundation shrub species in California to recover from damage. Desert shrubs are cleared and damaged by humans for many purposes includin...

Shrub fecundity is critical to long term persistence of fourwing saltbush (Atriplex canescens (Pursh) Nutt.) populations at our research site on the shortgrass steppe in Colorado. We conducted a 2-year experiment to test hypotheses concerning the impact of cattle-browsing on fecundity-related variables in fourwing saltbush. Protection from cattle browsing was significantly associated with flora...

Annual plants in semi-arid and arid areas are often closely associated with shrubs. The degree of association largely depends on the balance of negative and positive effects between these contrasting plant life-forms, ranging from interference to facilitation. Since positive interactions are predicted to become less important with increasing rainfall, the interaction balance is expected to shif...