| 摘要: |
| 【目的】研究半干旱黄土丘陵区4种灌木树种在不同坡位条件下的光合生理生态适应性，为该区人工植被建设中树种的合理配置提供科学依据。【方法】以陕西北部吴起县境内人工栽培的灌木林小叶杨(Populus simonii)、山杏(Armeniaca sibirica)、山桃(Amygdalus davidiana)、柠条(Caragana korshinskii)为试验材料，利用Li-6400便携式光合仪，测算其光合特性、蒸腾速率和水分利用率等生理生态指标，系统比较阳坡不同坡位条件下4种灌木树种的适应性及差异。【结果】从4种灌木树种的光响应曲线看，均没有出现光抑制现象，非直角双曲线模型对其光响应曲线的拟合效果良好，拟合系数(R2)均超过0.98；不同坡位条件下，4种灌木树种的叶片最大净光合速率(Pnmax)、平均瞬时蒸腾速率(Tr)、光补偿点(Lcp)和光饱和点(Lsp)均以坡上位最高；4种灌木树种在坡上位的叶片Pnmax排序为小叶杨＞山桃＞山杏＞柠条(P＜0.05)，在坡中位的排序为小叶杨＞山桃＞柠条＞山杏(P＜0.05) ；除小叶杨的叶片表观量子效率(a)以坡中位条件下显著最高(P＜0.05)外，其余3种灌木树种在坡上位与坡中位间无显著差异；不同坡位条件下，除山杏的叶片平均瞬时水分利用效率(WUE)以坡上位显著最高外(P＜0.05)，其余3种灌木树种均以坡中位显著最高(P＜0.05)。【结论】结合黄土丘陵沟壑区的水分环境条件来考虑，山杏较为适宜于在阳坡坡上位种植，而小叶杨、山桃和柠条适宜于在阳坡坡中位种植。 |
| 关键词: 光合特性 光响应曲线 蒸腾速率 水分利用效率 坡位 灌木 |
| DOI： |
| 分类号: |
| 基金项目:陕西省交通厅项目(05Hx01)；榆林市科技计划项目(Nygg200806)；陕西省教育厅科学研究计划项目(11Jk0652) |
|
| Photosynthetic and physiological characters of four shrub species in the Loess Hilly-Gully Region |
|
|
| Abstract: |
| 【Objective】In this paper,we studied the photo-physiological characteristics of four shrubs species from semiarid and hilly-gully loess region under different slope conditions,and the objective was to provide fundamental scientific evidence for the reasonable utilization and management to establish stable artifical grassland.【Method】We used Populus simonii,Armeniaca sibirica,Amygdalus davidiana,and Caragana korshinskii of Wuqi County,Shaanxi Province as the experiment material.The characteristics of photosynthetic,transpiration and water use efficiency of this four shrubs species were measured with Li-6400 photosynthesis systems to reveal their adaptability and differentce to different slope positions under sunny slope.【Result】The results indicated that there was no photoinhibition of photosynthesis of four shrubs species,and the non-rectangular hyperbola model could well simulate the photosynthesis-light response curves,with R2 over 0.98.The maximum net photosynthetic rate(Pnmax),average transpiration rate(Tr), light compensation point(Lcp) and light saturation point(Lsp) were the highest in upper slope under different slope positions.The significance order of Pnmax in upper slope position was P.simonii＞A.davidiana＞A.sibirica＞C.korshinskii(P＜0.05);and the order of middle slope position was P.simonii＞A.davidiana＞C.korshinskii＞>A.sibirica(P＜0.05).The apparent quantum efficiency(a) of P.simonii was the highest in middle slope position(P＜0.05),and the three other shrubs species between upper slope and middle slope position exhibited no significant difference.At different slope positions,the average water use efficiency(WUE) of A.sibirica was the highest in upper slope position and the three other shrubs species all were the highest in middle slope position.【Conclusion】Comprehensively considered,A.sibirica was acclimated in upper sunny slope position and P.simonii,A.davidiana and C.korshinskii in middle sunny slope position. |
| Key words: photosynthetic character light response curves transpiration water use efficiency slope position shrubs species |
