Effects of mulching management of Phyllostachys heterocycla forests on the characteristics of soil infiltration and biometrics in southwest Zhejiang Province, China
Soil infiltration,soil physical and chemical properties,root length density and soil fauna diversity were studied in Phyllostachys heterocycla forests with different mulching times in southwest Zhejiang Province,China.Significant differences of soil infiltration capability were found among the forests with different mulching times and among soil layers.Soil infiltration capability generally declined in the deeper soil layers.With mulching management,soil infiltration capability increased under the first mulching,and then declined with the increase of mulching times.The Kostiakov model was suitable for simulating soil infiltration process.With the extending of mulching times (4 to 6 years),soil pH and total/non-capillary porosity decreased,while soil bulk density,soil organic matter and total nitrogen contents increased significantly.Soil initial,steady,and average infiltration rates as well as the cumulative infiltration amount correlated closely with the length density of roots with diameter from 0.5 mm to 5.0 mm,showing a decreasing tendency with the decrease in root length density.Soil fauna density was highest in the forest under the first mulching,and was lowest after third mulching.The decreased numbers of large and meso-arthropods,including Symphyla,Chilopoda,Diplopoda,Hymenoptera and pseudoscorpions,and the micro-arthropods,including Oribatida,Mesostigmata,Onychiuridae,Neanuridae,Cyphoderidae,and Entomobryidae,showed negative effects on soil infiltration.In conclusion,long-term mulching changed soil physical and chemical properties,decreased soil infiltration capability,and suppressed the development of soil fauna,which might cause the decline of P.heterocycla forests.