نتایج جستجو برای: soil seed bank characteristics were compared between grazed and ungrazed areas therefore
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data envelopment analysis (dea) is a powerful tool for measuring relative efficiency of organizational units referred to as decision making units (dmus). in most cases dmus have network structures with internal linking activities. traditional dea models, however, consider dmus as black boxes with no regard to their linking activities and therefore do not provide decision makers with the reasons...
learning-oriented assessment seeks to emphasise that a fundamental purpose of assessment should be to promote learning. it mirrors formative assessment and assessment for learning processes. it can be defined as actions undertaken by teachers and / or students, which provide feedback for the improvement of teaching and learning. it also contrasts with equally important measurement-focused appro...
In most ecosystems, disturbance is an important agent of variation in community structure and composition. Determining the diversity and composition of soil seed bank is essential for designing conservation and restoration programs because it can markedly contribute to future plant communities. Despite the important role of soil seed banks in the composition of different plant communities, and...
the present study was conducted to investigate the role of summary in teaching grammar process on pre-university students. to this end, 48 male pre-university students in semnan were participants. they were math class that we called experimental group and science class as control group. in order to make sure there was no significant difference in proficiency level of two groups. a pre-test wa...
The effect of cattle grazing on the genetic structure of native grass populations has received little attention. We investigated the effect of cattle grazing on genetic variation in Idaho fescue (Festuca idahoensis Elmer) using ISSR (inter-simple sequence repeat) DNA markers. The ISSR markers are hypervariable and are generally interpreted as being selectively neutral. Idaho fescue tillers were...
This study was carried out to investigate the effect of crown canopy of Pistacia atlantica, Amygdalus scoparia and A. eburnea species on seed bank density (size). Ten individuals of each species were selected and one plot under and another plot outside of the crown canopy of each species were established. In each plot, soil sampling was done from 0-5 and 5-10 cm depths. The soil seeds were id...
al., 1994). Summed to 1-m depth, SOC content was not different between cropland and conservation reserve. Estimates of potential soil organic C (SOC) and total N (TN) In a shortgrass-steppe with 56 yr of grazing in Colorado, sequestration at depths below the traditional plow layer (i.e., 0–0.3 m) in agricultural systems are needed to improve our understanding of SOC was not different between un...
Grazing effect on vegetation cover and soil factors in natural environments is inevitable. The present study was conducted to investigate the effect of grazing on soil factors and distribution of plant species in grazed and non-grazed areas in rangelands of western parts of Hoz-e-Soltan Lake, Qom. Systematic-randomized sampling method was used alongside of 4 transects. Adjacent to the transects...
Tallgrass prairies have been reduced to less than 5% of their former range, yet provide essential habitats for many native plants and animals such as pollinators. Land managers work to preserve the biodiversity within these tallgrass prairies by implementing management techniques such as burning, haying, and patch-burn-grazing (PBG). All treatments utilize burning, but haying removes abovegroun...
The dominance of invasive species is often assumed to reflect their competitive superiority over displaced native species. However, invasive species may be abundant because of their greater tolerance to anthropogenic impacts accompanying their introduction. Thus, invasive species can either be the drivers or passengers of change.We distinguish between these two possibilities in California grass...
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