Non-additive Effects of Leaf Litter Mixtures from Robinia pseudoacacia and Ten Tree Species on Soil Properties

ABSTRACT

Litter decomposition plays a critical role in both nutrient cycling and the interspecific relationships between tree species. In this study, leaf litter from Robinia pseudoacacia was mixed with litter from 10 other species, this mixture was then ground and incubated in soil. The soil indexes (i.e., quantity of microbes, activities of enzymes, and chemical properties) were analyzed to study the effects of litter decomposition on soil properties and the interaction between the litters. If mixed separately with Larix principis-rupprechtii or Betula platyphylla, R. pseudoacacia litter exerted synergistic effects on the activities of most enzymes. The mixed litters of R. pseudoacacia and Pinus sylvestris var. mongolica or Ulmus pumila exerted synergistic effects on the soil available P. With regard to the soil properties as a whole, the mixed litters of R. pseudoacacia and B. platyphylla, Pinus tabulaeformis, P. sylvestris var. mongolica, or L. principis-rupprechtii exerted synergistic effects on soil during their decomposition. However, the mixed litters of R. pseudoacacia and Populus simonii, Quercus liaotungensis, U. pumila, or Caragana microphylla did not. This indicated that R. pseudoacacia mixed with the litter of other needle-leaf tree species benefits the development and regeneration of soil and thus can be used for sustainable forest management.

KEYWORDS:

• litter decomposition
• non-additive effect
• Robinia pseudoacacia
• soil enzyme
• soil nutrient

Acknowledgments

We thank Dawen Qian from the Northwest Institute of Plateau Biology, Chinese Academy of Sciences, for assistance in mapping. We also heartily acknowledge the input from anonymous reviewers and editors that improved earlier versions of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China [31400483], the National Program on Key Basic Research Project [2014CB954002], the Natural Science Foundation of Qinghai Province [2016-ZJ-923Q], and the Qinghai innovation platform construction project [2017-ZJ-Y20].