水保所知识产出(1956---)知识库

黄土丘陵沟壑区由于土壤侵蚀严重，天然植被恢复缓慢，植被稀疏，枯枝落叶层的生态效应就显得尤为重要。对该区坡沟
不同立地条件下草本群落主要物种的枯落物蓄积量、持水与养分潜在归还能力进行了分析，探讨主要物种枯落物对土壤的改善
作用。结果表明: 1) 坡沟不同立地条件下枯落物蓄积量差异显著( P＜0. 05) ，在73．74—175．26 g /m2 之间变化，表现为阴沟坡＞
峁顶＞阳沟坡＞阴梁峁坡＞阳梁峁坡; 在坡面不同微地形下也差异显著( P＜0. 05) ，在阳坡表现为株丛＞浅沟＞鱼鳞坑＞裸地，在阴
坡为浅沟＞鱼鳞坑＞株丛＞裸地，在峁顶为株丛＞裸地。2) 主要物种枯落物最大持水量可达自身干重的1．22—4．34 倍; 不同物种
枯落物间的持水能力差异极显著( P＜0. 01) ，表现为白羊草叶＞铁杆蒿叶＞白羊草茎＞达乌里胡枝子叶＞长芒草＞达乌里胡枝子枝
＞铁杆蒿枝。3) 枯落物C、N 含量分别在7．35%—40．33%和0．61%—1．60%之间，不同物种间差异极显著( P＜0. 01) ，同一物种枯
落物C、N 含量在坡沟不同立地条件下差异不显著。4) 影响枯落物分解的木质素含量( 1. 00%—8. 20%) 、纤维素含量( 3. 16%—
14．06%) 、木质素/N 值( 0．78—12．48) 、C/N 值( 5．61—57．41) 在不同物种间差异极显著( P＜0. 01) ; 同一物种木质素含量、纤维素
含量和木质素/N 值在坡沟不同立地条件下差异显著( P＜0. 05) ，而C/N 值不显著。5) 铁杆蒿叶的枯落物养分潜在归还能力最
大，达乌里胡枝子和白羊草的枯落物次之，长芒草的枯落物养分潜在归还能力最小。

Because of the serious soil erosion，the soil moisture and nutrients deficiency，the slowly recovery and scarcity of
natural vegetation in the hill-gully Loess Plateau，the ecological effects of litter layer are particularly important for litter
layer effective reduction on surface runoff and mitigate soil erosion． Thus，in this study，the litter accumulation ofcommunities and main herb species in different site conditions was investigated in the hill-gully Loess Plateau，water
holding capacity of litter of main herb species was measured by the immersion method，potential nutrient return capacity of
litter of main herb species was analyzed by measuring the nutrients content，lignin and cellulose content，then the effects of
main species litter on soil fertility improvement was discussed． It's important to understand the mechanism and efficacy of
the resistance of plants to soil erosion． The main results were as follows: 1) the accumulation of community litter was
between 73．74—175．26 g /m2，and was significantly different in slope-gully sites ( P＜0. 05) ，ordered as shady gully slope
＞ hilltop ＞ sunny gully slope ＞ shady hilly slope ＞ sunny hilly slope． While in micro-sites ordered as under vegetation ＞
ephemeral gully ＞ fish-scale pit ＞ bare land on the sunny slope，ephemeral gully ＞ fish-scale pit ＞ under vegetation ＞ bare
land on the shady slope and under vegetation ＞ bare land on the hilltop． 2) The maximal water holding capacity of litter of
main species was up to 1．22—4．34 times of its dry mass，and it was extremely significantly different among species ( P＜
0. 01) ，ordered as the defoliation of Bothriochloa ischaemun ＞ the defoliation of Artemisia gmelinii ＞ the deadwood of
Bothriochloa ischaemun ＞ the defoliation of Lespedeza davurica ＞ the litter of Stipa bungeanaon ＞ the deadwood of Lespedeza
davurica ＞ the deadwood of Artemisia gmelinii． 3) The organic carbon content ( 7． 35%—40． 33%) and total nitrogen
content ( 0．61%—1．60%) of species were extremely significant different among species ( P＜ 0. 01) ，but they were not
significantly different in slope-gully sites． 4) Indicators that influenced litter decomposition ( such as lignin content，
cellulose content，lignin /N ratio，C/N ratio) were extremely significant different among species ( P＜ 0. 01) ． The lignin
content ( 1．00%—8．20%) and cellulose content ( 3．16%—14．06%) and lignin /N ratio ( 0．78—12．48) were extremely
significantly different in slope-gully sites ( P＜0. 05) ，while C/N ratio ( 5．61—57．41) was not significantly different． 5)
The potential nutrient return capacity of Artemisia gmelinii defoliation was the highest，followed by the litter of Lespedeza
davurica and Bothriochloa ischaemun，and the litter of Stipa bungeanaon was the lowest． In conclusion，the water holding
capacity and the potential nutrient return capacity of Bothriochloa ischaemun litter on the sunny slope and the defoliation of
Artemisia gmelinii and Lespedeza davurica on the hilltop and shady slope were the highest among species in slope-gully sites，
they could effectively improve the soil fertility． While，the litter of Stipa bungeanaon water holding capacity and the
potential nutrient return capacity both were the lowest among species in slope-gully sites． The soil fertility effects of different
species should be considered when the vegetation was used to control soil erosion． The species should be chosen which not
only could control soil erosion but also significantly improve soil fertility，and then the soil quality could be slowly improved．
Therefore，Bothriochloa ischaemun，Artemisia gmelinii and Lespedeza davurica were the good choice to control soil erosion on
the slopes．