乌兰布和沙漠绿洲防护林杨树叶片性状研究

以新疆杨（Populus alba var. pyramidalis Bge.）、美青杨（Populus deltoides×Populus cathayana）杂种2个无性系（93-8-6、3-69）为研究对象，测定了3种杨树的叶片性状，分析了叶面积、叶干物质含量等叶片性状之间的相关性，并探讨了3种杨树对乌兰布和沙漠贫瘠与干旱环境的适应能力。结果表明：①叶面积、叶长、叶宽、叶周长、叶长宽比均为美青杨杂种93-8-6>美青杨杂种3-69>新疆杨，叶形指数为新疆杨>美青杨杂种93-8-6>美青杨杂种3-69。②3种杨树之间的比叶面积与叶干物质含量均存在显著差异（P<0.05）。美青杨杂种93-8-6、美青杨杂种3-69、新疆杨比叶面积分别为20.570±1.506、17.562±2.827和13.347±0.824 m2·kg-1，叶干物质含量分别为220.748±4.493、246.015±7.594和299.431±6.011 mg·g-1。③比叶面积与叶干物质含量存在显著负相关关系（P<0.05），两者呈指数函数关系（y=ae-bx）；干重与叶面积存在显著正相关关系（P<0.05），两者呈幂函数关系（y=axb）；干重与比叶面积存在显著负相关关系（P<0.05），两者呈线性函数关系（y=-ax+b）。比叶面积、叶干物质含量能够很好地反映3种杨树对乌兰布和沙漠贫瘠与干旱环境的适应能力，新疆杨适应能力更强，建议今后该区防护林体系的更新可适当增加新疆杨的种植比例。

Study on Leaf Trait of Poplar in Protection Forest at Ulan Buh Desert Oasis

Taking three poplar species(Populus alba var. pyramidalis Bge., two clones (93-8-6, 3-69) of Populus deltoides ×Populus cathayana) as the research object, this paper determined leaf traits of the three kinds of poplar, analyzed the correlation among leaf traits, such as leaf area, leaf dry matter content, etc., and explored the adaptability of three poplar species to Ulan Buh Desert. The results showed that: ① The rank of leaf area, leaf length, leaf width, leaf perimeter, leaf length and width ratio were Populus deltoides×Populus cathayana 93-8-6>Populus deltoides×Populus cathayana 3-69>Populus alba var. pyramidalis Bge., leaf factor was Populus alba var. pyramidalis Bge.>Populus deltoides×Populus cathayana 93-8-6> Populus deltoides×Populus cathayana 3-69. ② There were significant differences in specific leaf area and leaf dry matter content (P<0.05) among the three species. The specific leaf area of Populus deltoides×Populus cathayana 93-8-6, Populus deltoides×Populus cathayana 3-69 and Populus alba var. pyramidalis Bge. were 20.570±1.506, 17.562±2.827 and 13.347±0.824 m2·kg-1, respectively. The leaf dry matter content of three species were 220.748±4.493, 246.015±7.594 and 299.431±6.011 mg·g-1, respectively. ③ The specific leaf area was significantly and negatively related to the leaf dry matter content (P<0.05), which displayed an exponential function relationship (y=ae-bx). The dry leaf weight was significantly and positively related to the leaf area(P<0.05), which displayed a power function relationship (y=axb ). The dry leaf weight was significantly and negatively related to the specific leaf area(P<0.05), which displayed a linear function relationship (y=-ax+b). The adaptability to the infertility and drought was well reflected by specific leaf area and leaf dry matter content. Populus alba var. pyramidalis Bge. showed better adaptability to the infertility and drought environments in Ulan Buh Desert, so the proportion of Populus alba var. pyramidalis Bge. in the restoration of protection forest should be increased in Ulan Buh Desert Oasis.