نتایج جستجو برای: phenological stage
تعداد نتایج: 358156 فیلتر نتایج به سال:
This study was conducted to determine some mineral content concentration in soil and plant of three elevation classes (1500, 2200 and 3000m) and two phenological stages of flowering and seedling start in north-facing slopes of Sabalan rangelands. Soil samples from the depth of 20cm and plant samples using 1×1m plots with 10 replications were collected. After sample preparation, the concentratio...
To generate realistic projections of species' responses to climate change, we need to understand the factors that limit their ability to respond. Although climatic niche conservatism, the maintenance of a species's climatic niche over time, is a critical assumption in niche-based species distribution models, little is known about how universal it is and how it operates. In particular, few studi...
Phenology--the timing of biological events--is highly sensitive to climate change. However, our general understanding of how phenology responds to climate change is based almost solely on incomplete assessments of phenology (such as first date of flowering) rather than on entire phenological distributions. Using a uniquely comprehensive 39-y flowering phenology dataset from the Colorado Rocky M...
Traditionally fuel maps are built in terms of 'fuel types', thus considering the structural characteristics of vegetation only. The aim of this work is to derive a phenological fuel map based on the functional attributes of coarse-scale vegetation phenology, such as seasonality and productivity. MODIS NDVI 250 m images of Sardinia (Italy), a large Mediterranean island with high frequency of fir...
Climate change may disrupt interspecies phenological synchrony, with adverse consequences to ecosystem functioning. We present here a 40-y-long time series on 10,425 dates that were systematically collected in a single Russian locality for 97 plant, 78 bird, 10 herptile, 19 insect, and 9 fungal phenological events, as well as for 77 climatic events related to temperature, precipitation, snow, i...
هدف: در این مطالعه به بررسی ارتباط ki-67 با stage سرطان سینه در بیمارستان بوعلی طی سالهای 90-1389 پرداختیم. روش مطالعه: در این مطالعه توصیفی – تحلیلی مقطعی، 144 نفر از مراجعین به بیمارستان بوعلی از سال 89 تا 90 مورد بررسی قرار گرفتند که به صورت در دسترس انتخاب و وارد مطالعه شدند. یافته ها: ki-67 در 9/81 درصد از بیماران مثبت بود. stageتومور در 4/26 درصد یک، در 2/47 درصد دو و در 4/26 درصد سه بو...
Background and objectives: Variation of active substances in medicinal plants during growth has been studied and the optimum harvest time has been determined for many medicinal plants. Ducrosi anethifolia is one the species belonging to Apiaceae family that has been used to improve the odor of food and drink. It is used also to treat catarrh, headache and backache in f...
Hedysarum flexuosum L. is an important forage legume with high nutritive value. The determination of forage production in natural habitats is the most important factor for grazing management. Studies on its habitat characteristics and distribution are scarce. This research was conducted in order to evaluate the extent of pheno-morphological diversity in natural populations of Hedys...
Changes in vegetation phenology are recognized as being possibly the most important early indicator of the impact of climate change on ecosystems. Time series of image data are accepted as being the best way to map these changes, if we can derive suitable indices from the huge volumes of time series data that make the interpretation of these time series difficult. The problem is thus to derive ...
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