نتایج جستجو برای: total canopy cover
تعداد نتایج: 911411 فیلتر نتایج به سال:
We examined the effects of shade from multiple kelp canopy layers (surface Macrocystis pyrifera canopy, understory Pterygophora californica canopy), both individually and in combination, on an understory algal assemblage in a central Californian kelp forest. The removal of both kelp canopies resulted in a dense recruitment of the understory brown alga Desmarestia ligulata that formed a third ca...
Fire and Vegetation Effects on Productivity and Nitrogen Cycling across a Forest–grassland Continuum
Mixed tree–grass vegetation is important globally at ecotones between grasslands and forests. To address uncertainties vis-à-vis productivity and nitrogen (N) cycling in such systems we studied 20 mature oak savanna stands, ranging from 90% woody dominated to 80% herbaceous dominated, growing on comparable soils in a 32-yr-old fire frequency experiment in Minnesota, USA. Fire frequencies ranged...
Biomass is a key factor in dynamics evaluation of ecosystems, biodiversity level and their stability. Biomass measurement is performed every year to evaluate range ecosystems (investigating the trend of changes), range management (suitable browsing systems) and cover assessment in rangelands. As direct biomass measurement is time-consuming, has costs and destroy rangelands non-destructive metho...
understanding the relationship between root yield and other traits in sugar beet may be a crucial step towards successful breeding of this important crop. path analysis provides a useful method in analyzing the genetic and phenotypic coefficients of correlations. this method is able to effectively unveil direct and indirect effects among traits of interest. in this research, root yield, yield c...
Much interest lies in long-term recovery rates of sagebrush communities after fire in the western United States, as sagebrush communities comprise millions of hectares of rangelands and are an important wildlife habitat. Little is known about postfire changes in sagebrush canopy cover over time, especially at a landscape scale. We studied postfire recovery of shrub canopy cover in sagebrush-ste...
Due to the harsh environmental conditions in arid and semi-arid area of country, it is essential to assess the factors affecting the vegetation in such areas. This study aimed to investigate the effect of some soil physicochemical properties (including texture, bulk density, moisture, organic matter, carbon, nitrogen, potassium, lime, sodium, electrical conductivity and pH) on Haloxylon persicu...
To detection of suitable sampling method to study tree canopy cover in the northern Zagros forest, Baneeh region forest, Kurdistan province, and west of Iran was selected. 40 square sample plots one hectare (100×100 m) were selected and perfect inventoried. In every sample plot the position of tree, kind of species and two diameter of crown (m) were recorded. To study of canopy cover different ...
This paper evaluates the potential of a terrestrial laser scanner (TLS) to characterize forest canopy fuel characteristics at plot level. Several canopy properties, namely canopy height, canopy cover, canopy base height and fuel strata gapwere estimated. Different approaches were tested to avoid the effect of canopy shadowing on canopy height estimation caused by deployment of the TLS below the...
Exclusion and not using of rangeland in the long term affects the composition and homogeneity of vegetation and consequently leads to the improvement of plants status. In this study, the characteristics and structural changes of the rangeland of Gonbad, Hamadan province, Iran, in 2014 (after 20 years of enclosure) were evaluated using Braun-Blanquet plot, Phytosociology and multivariate analysi...
Estimates of forest canopy cover are widely used in forest research and management, yet methods used to quantify canopy cover and the estimates they provide vary greatly. Four commonly used ground-based techniques for estimating overstory cover – line-intercept, spherical densiometer, moosehorn, and hemispherical photography – and cover estimates generated from crown radii parameters of the wes...
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