Characteristics Of Water-holding And Anti-erosion Capacity Of Forest Litter In Typical Stand Types In The Dabie Mountains

The Dabie Mountain area has a special location and is one of the 14 contiguous destituteareas determined by the state.It also belongs to the national key ecological function zone,is an important ecological security barrier in central China and the Yangtze River Delta,and shoulders the heavy responsibility of ecological security and ecological function.According to the 2017 survey data,the total area of soil and water loss reached 9520km²,and nearly2726.5t of soil was lost.Therefore,protection of important ecological functions such as forest water conservation and soil and water conservation in the Dabie Mountains has become one of the core tasks of regional development.As a link that connects plants and soil nutrient cycles,forest litter has the functions of increasing soil fertility,promoting nutrient cycling,maintaining ecosystem stability,maintaining hydro-ecological effects and forest carbon cycling.This study combined with previous studies on the water holding capacity of litter,based on the field sample survey,using the immersion method,artificial simulated rainfall and other experimental methods,For Anhui Dabie Mountain area distribution typical of Cunninghamia lanceolata forest,Pinus taiwanensis forest,Quercus serrata var.brevipetiolata and Castanea seguini mixed forest and Castanea seguinii and Pinus taiwanensis mixed forest litter water-holding characteristics and the ability to resist erosion is studied.By measuring the natural moisture content,water holding capacity,water holding rate,water absorption rate,and Quercus serrata var.brevipetiolata and Castanea seguinii mixed forest of different forest types,different levels of litter Anti-erosion capability and other indicators to explore the soil and water conservation capabilities of typical forest stand litter in the Dabie Mountains in forest ecosystems.The results were as follows:1)The existing litter size of the four forest types was Cunninghamia lanceolata forest?15.97±2.12?t/hm²,Pinus taiwanensis forest?8.01±0.44?t/hm²,Castanea seguinii and Pinus taiwanensis mixed forest?5.03±0.40?t/hm²,Quercus serrata var.brevipetiolata and Castanea seguinii mixed forest?3.81±0.16?t/hm²,respectively.Litterfall in Cunninghamia lanceolata forest was significantly higher than the other three stands?P<0.05?,and the existing litter between Quercus serrata var.brevipetiolata and Castanea seguinii mixed forest and Pinus taiwanensis forest were significantly different?P<0.05?.There was no significant difference among the existing litter amounts of Castanea seguinii and Pinus taiwanensis mixed forest,Quercus serrata var.brevipetiolata and Castanea seguinii mixed forest and Pinus taiwanensis forest?P>0.05?.2)The total water holding capacity of the four forests is ranked as follows:Cunninghamia lanceolataforest?38.43±1.07?t/hm²,Pinus taiwanensis forest?15.00±0.22?t/hm²,Quercus serrata var.brevipetiolata and Castanea seguinii mixed forest?10.58±0.44?t/hm²,Castanea seguinii and Pinus taiwanensis mixed forest?9.81±0.06?t/hm²,except that there is no significant difference between the total water holding capacity of Castanea seguinii and Pinus taiwanensis mixed forest and Quercus serrata var.brevipetiolata and Castanea seguinii mixed forest?p>0.05?,the remaining forest stands are significantly different?p<0.05?.3)There was an obvious logarithmic function relationship among litter water holding capacity?Y₁?,water holding rate and litter soaking time.The relationship of them was Y₁=alnt+b.Litter water holding rate?Y₂?decreaseed with the increasing of the immersion time,and they were has a power exponential function relationship.The relationship of them was Y₂=ktⁿ.Both of them reached a significant correlation level.4)Both the sequence of maximum water holding capacity and maximum water holding capacity of different layers of litter were decomposition layer>semi-decomposition layer>undecomposed layer.The maximum water holding capacity of the decomposition layer is about 1.25 times of the undecomposed layer.There was no significant difference between the maximum storage rate and the effective storage rate at different levels.?P>0.05?.5)The erosion resistance of litter in Quercus serrata var.brevipetiolata and Castanea seguinii mixed forest was closely related to the litter coverage per unit area,rainfall intensity,slope and other factors.Among them,when the litter amount is 200g/m²,the surface runoff at 40mm/h is reduced the effect is more obvious than when the rain intensity is 80mm/h.When the rain intensity and the amount of litter per unit area remain unchanged,the start runoff time at a slope of 10°is longer than the start runoff time at a slope of 20°.The rain intensity is 40mm/h and the slope is 10°.There was no significant difference between the reduction rate of total runoff and the amount of litter?P>0.05?.When the rainfall intensity is 40mm/h and the slope is 20°,the difference between the total runoff reduction rate of litter amount 200g/m²and litter amount 50g/m² was significant?P<0.05?.