Structural Characteristics and Eco-adaptability of Heteromorphic Leaves of Populus euphratica

The microstructural and ultrastructural traits of three kinds of typical leaves of Populus euphratica Olive, including lanceolate, broad-ovate and dentate broad-ovate leaves, were studied by using electron microscope and optical microscope. The re- sults showed that with the leaves changing from lanceolate shape to dentate broad-ovate shape, their structure obviously tended to be xeromorph: developed palisade tissue, undeveloped spongy tissue, thick cutin layer and sunken stomas. The amount of mitochondria tended to be increased, and the shape of chloroplasts varied from regular spindle to irregular rotundity or oval. The leaves were cov- ered with wax without cilium, and the stomas on the upper and lower epidermis of the leaves opened unevenly. The stomas on the lower epidermis were deeper than those on the upper epidermis under the scanning electron microscope. The results implied that the structural characteristics of the diversiform-leaves of P. euphratica are related to its eco-adaptability.

Analysis of Climatic Factors Causing Yield Difference in Ramie among Different Eco-regions of Yangtze Valley

[Objective] This study was to investigate the climatic factors affecting the regional eco-adaptability of ramie.[Method] Five experimental sites of different eco-types in ramie growing regions in Yangtze Valley were set up to investigate the yield of Zhongzhu No.2,based on which we assessed the adaptability of Zhongzhu No.2 to various eco-regions and further analyzed the climatic factors causing the difference in eco-adaptability.[Result] Ramie yield varied largely among various experimental sites and the yield difference appeared to be well repeatable,with a differential value between the maximum and the minimum reaching 2.3 kg/20 m2.Analysis of the yield data,together with climatic factors in various ecological regions showed that yield of Zhongzhu No.2 was significantly correlated with rainfall,sunshine hours,relative humidity during its growing period.Of the climatic factors,sunshine hours and rainfall can positively promote yield increase,while relative humidity negatively regulate ramie yield.[Conclusion] The climatic indices,including rainfall,sunshine duration and relative humidity are a key factor causing yield difference in ramie among different regions of Yangtze Valley.

Analysis on Ecological Adaptability of Hani Village Landscapes in Yuanyang,Yunnan Province

The eco-adaptation of the landscape in Hani villages consists of two stages.The first stage is the ecological selection and adaptation of the landscapes in Hani villages to the natural environment.The forest landscape ecosystem,the architectural landscape ecosystem,and the terraced landscape ecosystem are the concentrated manifestations of meeting production and living needs,adapting to topographic changes,and adapting to climate features.The second stage is the adjustment and improvement of the landscape in Hani villages to the built environment.It is embodied in the establishment of the Mysterious Woods,abundance of plants in the building group,construction of artificial ditches,production of water infrastructures,and abundance of landscape nodes.In the end,Hani villages have experienced a long process of selection,adaptation,improvement and perfection,and gradually formed a harmonious and unified landscape ecosystem.Through field investigation,this paper analyzed the landscapes of Hani villages from the angle of ecological adaptability.It mainly studied the formation causes of the village landscapes as a material carrier,the process of village landscape adapting to natural and built environment,and the inherent ecological significance,which is of imperative and realistic significance to promote the ecological protection and construction of Hani villages.