金沙江河谷特有植被丽江羊蹄甲群落特征研究

打开文本图片集

DOI：10.11931/guihaia.gxzw202412020

Abstract： The dry-warm valleyshrubland is asignificant vegetation type inthe middle Jinsha River valley.The Bauhinia bohnianashrubland isarecentlydiscovered relic endemiccommunityof this type.Current research onvalleyshrubland haslargely focusedondry-hotvalleyvegetation，andthereisalackofresearch onthecommunityandecological characteristics of dry-warm valley vegetation.This studyuseddrone photographyand thequadrat methodto investigate the characteristics and current distribution of the B .bohniana community. The results were as follows：（1） A total of 22 surveyed B . bohniana community quadrats recorded194 vascular plant species belonging to 57 familiesand 120 genera.Fabaceae and Poaceae werethe dominant families，while Carexand Selaginell were the dominant genera；the flora showed a tropical-temperate transitional pattern，with 56.52% tropical and 43.48% temperate genera； at the species level，Chineseendemicsdominate，including51indicatorspeciesof theJinshaRiverdry-warmvallys，reflectingrelict evolutionandspecialization drivenbythe Tethys retreatandtheupliftof the Qinghai-Tibet Plateau.（2）Thecommunity exhibited a distinct vertical structure，with shrub layer cover ranged from 30% to 70% ，herb layer from 10% to 50% ， and interlayer from 1% to 3% ；ithad a typical drought-deciduous appearance，turning sparse and yellow in the dry seasonand regreening in therainy season，witha significantlydelayed phenology compared to surrounding areas；the speciesdiversity indexof theshrub layerwashigherthan thatof the herb layer.（3）Thelife-formspectrum was dominated by hemicryptophytes （41.24% ）and phanerophytes（ 34.54% ）.Prominent adaptive traits included a predominance of small leaves （microphyll， 50.52% ），chartaceous （ 64.06% ），anda deciduous habit，which indicated convergent adaptation to drought stressThe community shared adaptive strategies with African savannas community and Mediterranean shrubland but had a higher proportion of temperate genera（ 43.48% ），highlighting its transitional nature.This study is of great significance for revealingthe historical evolutionof the Jinsha River vally，and provides a scientific basis for the ecological conservation of its middle reaches.

Key words：Bauhinia bohniana，dry-warm valley shrubland，community characteristics，speciescomposition， Jinsha River

金沙江位于中国西南地区，跨越青藏高原、横断山脉和云贵高原，是长江的上游河段（Lietal.，2020），对维护长江流域生态平衡和生物安全具有重要意义，一直是学界和业界高度关注的热点区域。（剩余16213字）