内蒙古砒砂岩区沙棘生理特征对平茬的响应

Response of the physiological characteristics of Hippophae rhamnoides in the arsenic sandstone area of inner Mongolia to stumping

以内蒙古砒砂岩区进入衰退期的沙棘(Hippophae rhamnoides)人工林为平茬处理,以未平茬处理的沙棘人工林为对照,测定不同平茬年限处理及对照的沙棘生理指标,研究侵蚀劣地内蒙古砒砂岩区沙棘人工林的衰退状况。结果表明:随着平茬年限的增加,沙棘的净光合速率、蒸腾速率和水分利用效率日变化均显著高于对照;平茬后沙棘的枝条边材比导率和叶比导率显著高于对照,但木材密度和栓塞度均显著低于对照;利用综合评价方法中较具优势的隶属函数评价法对沙棘各项生理指标进行综合评判,评判结果显示,综合生长优势由高到低依次为平茬3年、平茬2年、平茬1年和对照。

To study the decline status of Hippophae rhamnoides plantation in the eroded arsenic sandstone area of Inner Mongolia, declining H.rhamnoides plants in the area were stumped and unstumped ones were taken as the control group to study the physiological indicators of H.rhamnoides. Results showed that: The diurnal variation of net photosynthetic rate, transpiration rate and water use efficiency of H.rhamnoides was significantly better than that of the control group with the increase of stumping years;after stumping, the sapwood specific hydraulic conductivity and leaf specific conductivity of H.rhamnoides were significantly higher than those of the control group, but its wood density and embolization degree were significantly lower than those of the control group. The membership function evaluation method was adopted to comprehensively evaluate the physiological indicators of H.rhamnoides, and its growth advantage was stumping for 3 years>stumping for 2 years>stumping for 1 year>the control group.