The return and loss of litter phosphorus in different types of sand dunes in Horqin Sandy Land, northeastern China

Abstract

Litter phosphorus (P) return is important to maintain the P cycle andbalance in the sandy land of arid areas. In this study, we determinedthe loss and return of litter P in sand dune areas and elucidated theirrelationship. We investigated litter production and litter P amount, andsimulated leaf litter moving dynamics to understand the relationshipsbetween the loss of litter P and the total litter P, and between thereturn of litter P and the total litter P in active (AD),semi-stabilized (SSD) and stabilized (SD) dunes in Inner Mongolia,northeastern China. The vegetation litter P was 12.6, 94.5, and 201.6 mgP/m(2) in AD, SSD, and SD, respectively. A significant movement and lossof leaf litter P with time occurred on the three types of sand dunes. Asa result, the loss of P was 7.4, 46.9, and 69.8 mg P/m(2) and the returnof P was 5.5, 47.6, and 131.8 mg P/m(2) in AD, SSD, and SD,respectively. The relationship between both loss and return of P andtotal litter P in AD, SSD, and SD was revealed by linear regression. Theslope of the regression line indicated the rate of loss or return oflitter P. From AD to SD, the loss rate showed a declining slope (0.52,0.32, and 0.17 for AD, SSD, and SD, respectively), and the return rateshowed a rising slope (0.48, 0.67, and 0.83 for AD, SSD, and SD,respectively). The loss of litter P should be regarded in the localmanagement of vegetation and land in sand dune areas. Improvedvegetation restoration measures are necessary to decrease litter P lossto maintain the stability of ecosystems in sand dune areas.