关键词: 甘肃, 木本植物, 区系小区, 生活型, 果实类型, 水热因子

Abstract: Global changes have posed a profound impact on the earth's life system. The mechanism with which plant responds to global changes would help us to take measures on the practice of adjustment and optimization of ecosystem. Gansu, located along the northeast margin of Qinghai-Tibet Plateau, northwest of China, is quite divers in vegetation, physiognomic types and climate features. From the south to the north, there occurred subtropic evergreen broad-leaved forests, warm temperate broad-leaved forests, frigid-temperate coniferous forests as well as desert shrublands with a span of 10 latitudes and 15 longitudes(93°25'~108° 42'E, 32°18'~42°18'N).This paper, based on previous study on floristic inventories and partition of Gansu woody plant flora, focused on the study of correlation between the pattern of plant life form as well as fruit types and hydrothermic factors. 6 Floristic subregions(i.e., that of Zoulang, Zhongbu, Qilianshan, Tianshui, Longnan and Gannan)in Gansu were set for the statistic of life form and fruit types. Totally 1291 woody species belonging to 292genera, 94families were classified into 7 life-form spectra types, that is, lianas, big tree, tree, big shrub, shrub, small shrub as well as parasites and lianas. Some conclusions are as follows:(1)the factors of water and heat were correlated positively with plant life-form of arbor, lianas and parasites and negatively with that in small shrubs. Shrubs with the height of 1.5m ~3m were negatively correlated with annual mean precipitation and annual mean temperature and(2)hydrothermic factors were positively correlated with evergreen plant and negatively with deciduous plant.(3)The percentage of evergreen in Zoulang was fairly higher than that of Zhongbu where hydrothermic factors were relatively more available in contrast to Zoulang, which mainly resulted from the specific background of floristic origin in Zoulang.(4)Humidity was correlated positively with sarcocarp while negatively with dry fruit, which suggesting that moisture conditions might shape the allocation patterns of dry fruit and sarcocarp in a given communities. (5)Cone was correlated negatively with heat factors while positively with moisture. Key fruit, nut, drupe, follicle, caryopsis were positively correlated with hydrothermic factors. Berry was significantly posotively correlated with humidity degree. Capsule was negatively correlated with hydrothermic factors, which indicated that capsule might derived under cool and dry climate. Utricle was negatively correlated with annual mean precipitation. (6)Species diversity, life form and fruit type, height of tree were correlatively changed along a environmental gradient. To clarify the evolutionary sequence among plant fruits would be helpful to both disclose the pattern of fruits and further the study on the mechanism with which plant responds to environmental changes.

Key words: temperate forest, gansu, floristic subregion, life-form spectra, fruit-types, hydrothermic factors