Ecological scales of northern-steppe broad-leaved forests flora species (р. )

Abstract

Habitats determination is one of the important tasks of forest ecology. However, the straight habitats evaluation is impossible or difficult often especially for express-information obtained. Phytometer methods are an alternative of habitats evaluation.Phytometer methods are based on the scales usage. Phytometer scales are based upon indicated species or community localization in environmental factors axes. Factors are scoring by certain number of factors. The most often habitats are estimated by indicator species groups or all species of the community ratio. The most important methodical problems of phytometer usage are indicators and their features specification, indicator functions estimation, positive and negative indicators selected and association indicators with habitats.The most frequently in forest ecology habitat estimation based upon phytometer ratio, when all species used as phytometers which characterized by score for the most important ecological factors such as temperature, moisture, light, soils salt, acidity, nitric, aeration and moisture regimes.But the usage of these methods straight is related with a high probability of mistakes. Particularly, there are two types of phytometer scales – point and interval. The first is much more accurate, but in local conditions the species can characterize by great deviation from beginning score which based on optimum position in tolerance curve. For the interval scales the local species habitat score is difficult to define and average score characterized by mistakes such as point scale using. Thus, for each region the correction of ecological scales is important task and regional point scales can developed upon habitats species conditions.The Didukh scales (based on Ramensky’s and Tsyganov’s scales for vascular plants species ofRussiadeciduous forests) have been accepted as reference in the article. The adjustment species localization in scales carried out by phytometer realized niche evaluation for specific habitats. The species score defined as the centroids in a multidimensional environmental factors space. As the evaluation result the scales for 156 vascular plants species are developed for the deciduous forests of Northern Steppe of Ukraine. These scales can recommend for habitats evaluation for xerophilous and floodplain oak forests in arid steppe climates.