نتایج جستجو برای: ecotone of tree type
تعداد نتایج: 21269015 فیلتر نتایج به سال:
ecotones are zones of gradual changes from an ecological system to another.ecotones monitoring could be important to find out the reason for changes and limits. inthis research satellite data were used to analyze the ecotone boundary in fars steppicrangelands using irs liss iii and pan data of year 2006. the real vegetation map andecotones prepared through geo-eye images from google earth softw...
Background ; Objectives: Identifying the important influential factors is a great challenge in oncology studies. Decision tree is one of methods that could be used to evaluate the prognostic factors and classifying the patients' homogeneously. This method identifies the main prognostic factors and then determines the subgroups of patients based on those prognostic factors. The aim of this...
Xylem sap flux density (Fd) was measured, on a 43-year-old (mature) and three 4-year-old (young) mango (Mangifera indica L.) trees, using Granier-type probes. The relative influences of environmental variables were examined under well-watered condition. Circumferential variation in Fd was also investigated by placing sensors on the north, south-west and south-east sides of the mature tree. Sap ...
Background and Purpose: Survival tree model is a nonparametric method which can be used to identify the affecting factors from a specific time to the onset of an event. In this method, the categories are selected according to the most important factors. The purpose of this study was to determine the factors affecting the duration of breastfeeding in mothers and introduce the homogeneous subgrou...
Trees are the most important biological elements of forest ecosystems. The variability of the tree species composition inhabiting in the Oriental beech forest, not only forms different forest types but also has a remarkable impact on the species diversity of forest floor plants, due to the existence of trees in the overstory layer. In this research, forest types of an an Oriental beech were ide...
The tree-line ecotone in the Southern Urals is mostly formed by monospecific stands of Siberian spruce (Picea obovata Ledeb.). Spruce is an ecologically plastic, cold-tolerant species that presents various growth forms. Moreover, its growth is further affected by stressful environment factors, including low temperatures, snowless winters, and strong winds. Thus, the morphological variability of...
Projected changes in global climate have important ramifications for the future of national parks and other reserves set aside to conserve ecological uniqueness. We explored potential implications of climatic changes on lifeform distribution and growth at Wind Cave National Park (WCNP), South Dakota, which lies on a climatically determined ecotone between grassland and forest. Fire, promoted by...
Background & Objective: Prediction of health status in newborns and also identification of its affecting factors is of the utmost importance. There are different ways of prediction. In this study, effective models and patterns have been studied using decision tree algorithm. Method: This study was conducted on 1,668 childbirths in three hospitals of Shohada, Omidi and Mehr in city of Behshahr...
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