青藏高原3种生活型水生植物的热值及环境的影响  

Effects of environmental factors on gross caloric values of three life-forms aquatic plants on the Qinghai-Xizang Plateau,China

作　　者：汪洋[1] 苗琳琳[1] 于丹[1] 刘春花[1] 王忠[1] 

机构地区：[1]武汉大学生命科学学院,武汉430072

出　　处：《植物生态学报》2017年第2期209-218,共10页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(31300296)

摘　　要：热值反映了植物光合作用固定太阳辐射能的能力,是从能量转化和储存角度理解植物对环境适应的可靠指标。为了探究青藏高原地区的水生植物叶片热值特征及其环境影响,该研究采集了青藏高原地区143个位点的533个水生植物叶片样品,进行了其热值含量的测定,结合实测水体的p H值、溶氧量和盐度等指标,分析环境因子对植物叶片热值的影响。结果表明:在青藏高原地区,3种生活型的水生植物叶片热值大小表现为挺水型植物>浮叶型植物>沉水型植物;随纬度增加,挺水型和沉水型植物叶片热值呈现显著增加的变化趋势;而随海拔的升高,挺水型植物叶片热值显著降低,沉水型植物变化不显著。从环境因子影响来看,随着气温的降低,挺水型植物叶片热值显著增加,沉水型植物变化不明显;而随水体盐度的增加,挺水型和沉水型植物叶片热值均呈显著增加的趋势;溶解氧仅表现为与挺水型植物热值呈现负相关关系,p H值对两种生活型植物叶片热值均未表现出显著的影响。Aims Gross caloric value （GCV） reflected plants＇ capability of converting solar energy. It provided a reliable indicator of plants＇ adaptations to environments in perspective of energy conversion and fixation. The aims of this study were （1） to illustrate the characteristics of GCV of aquatic plants on the Qinghai-Xizang Plateau, （2） to ex- plore the geographical and environmental patterns and （3） to discuss the underlying mechanisms in forming the patterns. Methods In July and August 2015, we collected 533 samples of aquatic plants＇ leaves in 143 field sites on the Qinghai-Xizang Plateau, and measured their GCV using SDACM-4000 oxygen bomb calorimeter. Together with mean annual temperature （MAT） of climatic factor and properties of water body, this study compared the differences of GCV among submerged, emergent and floating-leaved plants by analysis of variance （ANOVA） and Tukey＇s HSD. We further regressed GCV of submerged and emergent plants against geographical and climatic factors and properties of water body by simple regression to explore the relative effects of environmental factors on GCV. Important findings On the Qinghai-Xizang Plateau, the mean GCVwas （15.95 ~ 3.90） kJ＇g-1. Among the three life forms, the rank of GCVwas the emergent plants （18.10 kJ＇g-1） 〉 the floating-leaved plants （16.77 kJ＇g-1） 〉 the submerged plants （14.31 kJ＇g-1）. With an increasing latitude, the GCV of emergent and submerged plants in- creased. Only GCV of emergent plants decreased with increasing altitude and temperature. The GCV of emergent and submerged plants increased with increased water salinity. Dissolved oxygen had significant negative effects on emergent plants, while pH value had no significant effects.

关 键 词：热值 水生植物 青藏高原 环境影响 

分 类 号：Q948[生物学—植物学]