Functional Traits And Correlations With Environmental Factors Of Cyperaceae In Diqing

Cyperaceae are a diverse family of plants with a wide range of habitats and garden ground cover applications,and are dominant habitat building species in forests,marshes and mountains,playing an important role in maintaining fragile ecological environments.Among the Cyperaceae,there is a relatively special evolutionary trait adapted to the environment,dauciform roots,which are produced more under alpine and low phosphorus conditions and have the unique ability to absorb phosphorus.In this study,we conducted a field study in Diqing Tibetan Autonomous Prefecture,Yunnan Province,to determine the functional traits of Cyperaceae representing common Cyperaceae and Cyperaceae with dauciform roots,and to determine the environmental factors around the plants to study Cyperaceae in different habitats,and the main results are as follows:(1)The survey was conducted in the field at 28 sample sites,with 84 soil samples collected from 16 species of Cyperaceae: Carex nubigena,Kobresia capillifolia,Cyperus fuscus,Kobresia cercostachys,Carex inanis,Kobresia pygmaea,Carex parva,Carex chiwuana,Carex scolopendriformis,Blysmus sinocompressus,Carex speciosa,Kobresia filicina,Kobresia fragilis,Kobresia cuneata,Pycreus sanguinolentus,and Eleocharis yunnanensis.Among them,there are two species of dauciform roots in the Cyperaceae:Kobresia filicina and Kobresia capillifolia.Among 289 Kobresia filicina and 93 Kobresia capillifolia,45 and 22 plants with dauciform roots were screened and observed,respectively.(2)The roots of Cyperaceae are mostly concentrated in the surface layer of 0-5 cm soil,and there is a tendency of root refinement,indicating that the survival of plants in poor soil will make the lower part of the ground tend to be superficial and root refinement,and this degree will deepen with the increase of altitude.The number of root tips and root forks of Cyperaceae tend to be distributed in the superficial root system,which also shows that the root system of Cyperaceae grows to the superficial layer in alpine meadows.(3)The plant height,leaf area,leaf shape index and phosphorus content of Cyperaceae decreased with increasing altitude and increased with increasing temperature;plant height decreased with increasing soil capacity;root length,surface area,projected area,volume,phosphorus content and biomass increased with increasing soil water content;plant height,leaf area,specific leaf area and leaf shape index increased with increasing p H;carbon and nitrogen content in the plant decreased with increasing p H;root length,surface area,projected area,volume,biomass and root to crown ratio increased with increasing soil nitrogen and phosphorus content.(4)The number of dauciform roots and the number of juvenile dauciform roots in Cyperaceae increased with increasing carbon and nitrogen content in the soil and decreased with increasing p H;the carbon content in the plant increased with increasing carbon,nitrogen and phosphorus content in the soil;the phosphorus content in the plant decreased with increasing carbon,nitrogen and phosphorus content in the soil and increased with increasing p H.In addition,the nitrogen and phosphorus contents and biomass in dauciform root plants of Cyperaceae were significantly greater than those of plants in Cyperaceae that did not contain dauciform roots.(5)Dauciform roots have strong biological significance.The existence of dauciform roots can increase the ability of Cyperaceae plants in barren areas to absorb nutrient elements,so that they can show higher ecological adaptability.In poor environment,they also correspond to better phenotypes,so as to improve productivity and narrow the difference between plants growing in good environment and those growing in poor environment.Through the adsorption activation of its own root hairs,it absorbs surrounding elements and promotes the development of plant leaf morphology and root traits toward environmental adaptability.