Analysis of the distribution of weed species on segetal and ruderal habitats

The specific structure of weed plants is created under the influence of complex of conditions and is exposed to continuous changes. The studying of dynamics of distribution of weed plants taking into account ruderal habitats allows revealing changes of structure of a weed element of flora. The results of inspection of agricultural grounds and ruderal habitats of Sukhobuzimsky District of Krasnoyarsk Region are presented in the study. The surveyed area is located in insufficiently warm place: GTK is equal to 1.2-1.4, the rainfall drops out in a year are 300-470 mm, and from the temperature above 10 degrees Centigrade is 200-240 mm. The sum of active temperatures above 10 degrees Centi-grade is equal to 1600-1800. The frost-free period lasts 85 days. The Krasnoyarsk forest-steppe be-longs to the most developed territories of Central Siberia. The most part of the area is occupied with farmlands. The community of weed views of terri-tories of the Sukhobuzimsky District of Krasno-yarsk Region consists of 95 types belonging to 51 sorts from 25 families. From total number of weed types 5 belong to segetal (5.3 %), 32 belong to segetal and ruderal (33.7 %), 46 are ruderal and segetal (48.4 %), 12 ruderal (12.6 %). Among seg-etal and segetal and ruderal 39 % of total number of types together are necessary. The weed plants relating to category of segetal and segetal and ruderal types are steadiest and plentiful in crops. Now from 28 prevailing weed types on segetal and segetal and ruderal have 67.8 % of total number, from them 15 types prevail in a weed component more than 50 years. The types dated for segetal and segetal and ruderal habitats live in an agrohpytocenose of grain crops.