نتایج جستجو برای: less than 625 individuals per hectare

تعداد نتایج: 2634328  

Extended abstract 1- INTRODUCTION The contribution of crop cover to reducing runoff and erosion depends on the type, height, density and stage of plant growth. The literature review indicates that because of the different life forms, the effect of plants on the reduction of runoff and erosion are different at different growth stages [13]. However, no comprehensive studies have been conduc...

Natural regeneration is one of the key aspects of forest sustainability and a tool to decide on restoration programs in forest areas. The purpose of this study was to investigate the quantity of natural regeneration of Acer campestre L. as one of the most important tree species in Arasbaran forests and its relationship with elevation changes and structural characteristics in the natural stands....

In order to study the effect of zinc and magnesium on agronomic and seed germination traits of wheat (Sivand cultivar), the current study was carried out at Mahidasht Agricultural Research Station in Kermanshah over the years 2012 and 2013. The experiment was conducted as factorial based on completely randomized block design with three replications. The treatments consisted of four levels of zi...

2001

We examined aspects of the population ecology of the Pacific Tree Frog (Hyla regilla) in a meadow of Corn Lily (Veratrum californicum) in the Sierra Nevada Mts. during July 2000. Using mark-recapture techniques we estimate the abundance of H. regilla to be 25±6.8 individuals which translates into a population density of 223.2±60.7 individuals per hectare. The sex ratio of the population of anim...

2008
Mark J. Ducey Michael S. Williams Jeffrey H. Gove Harry T. Valentine

Perpendicular distance sampling (PDS) is a fast probability-proportional-to-size method for inventory of downed wood. However, previous development of PDS had limited the method to estimating only one variable (such as volume per hectare, or surface area per hectare) at a time. Here, we develop a general design-unbiased estimator for PDS. We then show how that estimator can be used to develop s...

Journal: :Science 1967
G M Woodwell C F Wurster P A Isaacson

DDT residues in the soil of an extensive salt marsh on the south shore of Long Island averaged more than 13 pounds per acre (15 kilograms per hectare); the maximum was 32 pounds per acre (36 kilograms per hectare). A systematic sampling of various organisms from the vicinity showed concentrations of DDT increasing with trophic level through more than three orders of magnitude from 0.04 part per...

Journal: :Plant physiology 1990
M K Schon D G Blevins

Our previous work demonstrated that boron (B) supplied to soybeans (Glycine max [L.] Merrill cv ;Williams 82') by a stem infusion technique increased the number of pods on branches and led to a significant yield increase. Therefore, research was continued to determine whether soil or foliar applications of B could be used to achieve the same results. Field experiments were completed with both s...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده ادبیات و علوم انسانی 1386

the purpose of the present study is to find out whether bilinguals of khuzestan-arab origin or monolinguals of iranian origin code-switch during learning or speaking english and which group is more susceptible to code-switch. to this end, the students of 24 classes from high schools and pre- university centers were screened out, and interviewed and their voices and code-switchings were recorded...

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