六盘山叠叠沟华北落叶松人工林叶面积指数的时空变化特征
The Spatio-Temporal Variation of LAI of the Larix principis-rupprechtii Plantation Ecosystems at Diediegou of Liupan Mountains of Northwest China
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摘要: 在具有半干旱气候的宁夏固原六盘山区叠叠沟小流域,于2009年整个生长季内(5—10月)监测了典型阴坡坡面上的华北落叶松人工林不同坡位的7个样地的林冠层、林下灌木层和草本层的叶面积指数(LAI)的数量变化和季节动态。结果表明:(1)华北落叶松不同样地的林冠层LAI随坡位升高的变化趋势基本上是逐渐减小,从坡下部的1.52-2.95减少到坡顶部的0.15-0.27;林下灌木层LAI是先增加后减小,从坡下部的0.05-0.06增加到坡中上部的0.73-1.01后再减小到坡顶的0.19-0.30;草本层的LAI随坡位上升不断增加,从0.18-0.36增加到0.19-0.75。(2)林冠层和草本层的LAI季节变化趋势都呈先上升、达到最大值后再下降的单峰曲线。在生长季初期(5—6月),林冠层LAI的增长比草本的快,而在生长季中期(7—8月)却比草本层的慢,这是由温度和土壤水分条件及根系层深度差别共同决定的。(3)随着林冠郁闭度增加,林冠层的LAI几乎线性增大;灌木层LAI随林冠郁闭度增加先增大后逐渐减小,在0.5左右达到最大值,在0.9以后几乎为零;草本层LAI随林冠郁闭度增加缓慢线性减小,从0.74降到0.35;灌草层(灌木加草本)LAI在林冠郁闭度0.4-0.5时最高并超过林冠层的LAI,在0.6以后急剧减少并开始低于林冠层LAI;总LAI随林冠郁闭度增加先急剧增加,在郁闭度0.6-0.8之间保持最大且相对稳定,之后轻微下降。Abstract: From the observation of 1eaf area index (LAI) of 7 Larix principis-rupprechtii plantation plots at 3 layers (tree canopy, shrubs and herbage) on the north slope in the vegetation period (May-Oct.) of 2009, the change of LAI along slope position, the vertical composition of LAI and its seasonal variation were studied at the semi-arid watershed of Diediegou, which locates at Liupan Mountains of Northwest China. The results showed: 1) The LAI of tree canopy decreased basically with rising slope position, from 1.52—2.95 at slope foot to 0.15—0.27 at slope top; the LAI of shrubs layer increased at first and then decreased with slope position, from 0.05—0.06 at slope foot to 0.73—1.01 at up-middle slope and 0.19—0.30 at slope top; while the LAI of herbage layer increased slowly, from 0.18—0.36 at slope foot to 0.19—0.75 at slope top. 2) The seasonal variation of LAI of tree canopy and herbage layers showed the same tendency, i.e. a one-peak curve of increase and then decrease with time. However, the LAI of tree canopy layer grew faster than that of herbage layer in the early vegetation period (May-Jun.) and slower than that of the herbage layer in the middle vegetation period (Jul.–Aug.), due to the integrated result of varying temperature and soil moisture as well as the root depth difference between trees and grasses. 3) With increasing tree canopy density, the LAI of each vegetation layer responded differently. The tree canopy LAI nearly linearly increased with canopy density; the LAI of shrubs layer increased at first and then decreased, with a maximum when the canopy density was about 0.5 and decreased to nearly zero when canopy density above 0.9; the LAI of herbage layer decreased gradually, from 0.74 to 0.35; the LAI of undergrowth (shrubs plus herbage) reached its maximum value and higher than tree canopy LAI when canopy density varied between 0.4—0.5, but decreased rapidly and lower than canopy LAI when canopy density above 0.6; the total LAI of all the 3 layers increased at first with rising canopy density, reaching its maximum and keeping relatively stable when canopy density was 0.6—0.8, and then slightly decreased with rising canopy density.
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Key words:
- Liupan Mountains
- / Larix principis-rupprechtii
- / forest canopy
- / shrubs
- / herbage
- / LAI
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[1] Lee K S, Cohen W B, Kennedy R E, et al. Hyperspectral versus multispectaral data for estimating leaf area index in four different biomes[J]. Remote Sensing Environment, 2004,91:508-520 [2] 吴伟斌,洪添胜,王锡平,等.叶面积指数地面测量方法的研究进展[J].华中农业大学学报,2007,26(2):270-275 [3] Sellers P J, Hall F G, Asrar G, et al. The first LSLSCP field experiment (FIFE) [J].Bulletin 0f the American Meteorological Society, 1988,69:22-27 [4] Sellers P, Schimel D. Remote-sensing of the land biosphere and biogeochemistry in the EOS era science priorities, methods and implementation[J].Global and Planetary Change, 1993,7(4):279-297 [5] Davi H, Aret F, Uc R, et al. Effect of thinning on LAI variance in heterogeneous forests[J]. Forest Ecology and Management, 2008,56:90-99 [6] Chen J M, Rich P M, Gower S T, et al. Leaf area index of boreal forests: Theory, techniques, and measurements[J]. Journal of Geophysical Research, 1997,102:29429-29443 [7] Asner G P, Scurlock J M O, Hicke J A, Global sythesis of leaf area index observation: Implications for ecological and remote sensing studies[J].Globe Ecology and Biogeography, 2003,12:191-205 [8] Yu Peng tao, Krysanova V, Wang Yanhui et al. Quantitative estimate of water yield reduction caused by forestation in a water-limited area in Northwest China[J]. Geophysical Research Letters, 2009,36, L02406, doi:10.1029/2008GL036744 [9] Wang Yanhui, Yu Pengtao, Xiong Wei, et al.Water Yield Reduction after Afforestation and Related Processes in the Semiarid Liupan Mountains, Northwest China[J]. Journal of the American Water Resources Association, 2008, 44(5): 1086-1097 [10] Wang Yanhui, Xiong Wei, Yu Pengtao, et al. Study on the evapotranspiration of forest and vegetation in dryland[J]. Science of Soil and Water Conservation, 2006,4(4):19-25 [11] Liu Jianli. Study on the soil water vegetation carrying capacity on slopes in the small watershed of diediegou of Liupan Mountain . Ph.D dissertation, Chinese Academy of Forestry, 2008 [12] 刘建立,王彦辉,熊 伟,等.六盘山叠叠沟小流域典型坡面土壤水分的植被承载力[J].植物生态学报,2009,33(6):1101-1111 [13] 王俊玲,金红喜,杨占彪,等.六盘山华北落叶松人工林多样性、生产力研究[J].兰州大学学报:自然科学版, 2008,44(1):31-33 [14] 刘志刚,马钦彦.华北落叶松不同类型林木的冠结构与光的分布[J].河北林果研究,1997,12(2):100-102 [15] 段争虎,肖洪浪,宋耀选,等.黄土高原西部兰州市郊地貌驱动的土壤水分变化及对植物的影响分析[J].中国沙漠, 2006,26(4):522-526 [16] 赵传燕,沈卫华,彭焕华.祁连山区青海云杉林冠层叶面积指数的反演方法[J].植物生态学报,2009,33(5):860-869 [17] Qiu Yang, Fu Bojie, Wang Jun, et al. Spatial variability of soil moisture content and its relation to environmental indices in a semi-arid gully catchment of the loess plateau [M].China: Journal of Arid Eavionments , 2001 [18] 王红梅,谢应忠,陈来祥.黄土高原坡地土壤水分动态特征及影响因素[J].宁夏农学院学报,2004,25(4):62-66 [19] 杜阿朋,于澎涛,王彦辉,等.六盘山北侧叠叠沟小流域土壤物理性质空间变异的研究[J].林业科学研究,2006,9(5):547-554 [20] 李根柱,王贺新,朱教君.辽东次生林区主要阔叶林型叶面积指数季节动态[J].生态学杂志,2008,27(12):2049-2055 [21] 陈 厦,桑卫国.暖温带地区3种森林群落叶面积指数和林冠开阔度的季节动态[J].植物生态学报,2007,31(3):431-436 [22] 吕瑜良,刘世荣,孙鹏森,等.川西亚高山暗针叶林叶面积指数的季节动态与空间变异特征[J].林业科学,2007,43(8):3-5 [23] 尹 婧,邱国玉,何 凡,等.半干旱黄土丘陵区人工林叶面积特征[J].植物生态学报,2008,32(2):440-447 [24] 关德新,吴家兵,王安志,等.白山红松针阔叶混交林林冠层叶面积指数模拟分析[J].应用生态学报,2007,18(3):499-503 [25] 彭方仁,黄宝龙.板栗密植园树冠结构特征与光能分布规律的研究[J].南京林业大学学报,1997,21(2):27-30 [26] 刘晓东,朱春全,雷静品,等.杨树人工林冠层光合辐射分布的研究[J].林业科学,2000,36(3):3-6 -
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