Early effects of crop tree management on undergrowth plant diversity and soil physicochemical properties in a Pinus massoniana plantation

Qian Lyu; Yi Shen; Xianwei Li; Gang Chen; Dehui Li; Chuan Fan

doi:10.7717/peerj.11852

Early effects of crop tree management on undergrowth plant diversity and soil physicochemical properties in a Pinus massoniana plantation

PeerJ. 2021 Jul 29:9:e11852. doi: 10.7717/peerj.11852. eCollection 2021.

Authors

Qian Lyu¹, Yi Shen¹, Xianwei Li^{1

2}, Gang Chen^{1

2}, Dehui Li³, Chuan Fan^{1

2}

Affiliations

¹ College of Forestry, Sichuan Agricultural University, Cheng Du, China.
² Key Laboratory of National Forestry and Prairie Bureau on Forest Resources Conservation and Ecological Security in the Upper Reaches of Yangtze River, Sichuan Agricultural University, Cheng Du, China.
³ College of Urban and Rural Planning and Construction, Mianyang Normal University, Mian Yang, China.

Abstract

Background: Soil and understory vegetation are vital components of forest ecosystems. Identifying the interaction of plantation management to vegetation and soil is crucial for developing sustainable plantation ecosystem management strategies. As one of the main measures of close-to-nature management of forest plantation, few studies have paid attention to the effect of crop tree management on the soil properties and understory vegetation.

Methods: A 36-year-old Pinus massoniana plantation in Huaying city, Sichuan Province was taken as the research object to analyse the changes in undergrowth plant diversity and soil physicochemical properties under three different crop tree densities (100, 150, and 200 N/ha).

Results: Our results showed that the contents of available phosphorus, organic matter and hydrolysable nitrogen in the topsoil increased significantly after crop tree management, while content of available potassium decreased. The composition of shrub and herb layer was richer, and the dominant species were obviously replaced after crop tree management. The Shannon-Wiener index and Richness index of shrub layer, and the diversity of herb layer increased significantly after crop tree management. Herb layer diversity indexes and Richness index of shrub layer were closely related to soil organic matter, available phosphorus, hydrolysable nitrogen, available potassium, soil moisture and bulk density. As the main limiting factors for plant growth, nitrogen, phosphorus and potassium were closely related to plant diversity and to the distribution of the dominant species. At the initial stage of crop tree management, each treatment significantly improved the soil physicochemical properties and plant diversity of Pinus massoniana plantation, and the comprehensive evaluation was 200 N/ha >100 N/ha >150 N/ha >CK. Compared with other treatments, 200 N/ha had the best effect on improving the undergrowth environment of the Pinus massoniana plantation in the initial stage of crop tree management.

Keywords: Crop trees; Dominant species; Plant diversity; Soil physicochemical properties.

Grants and funding

This study was funded by a Pillar Project of the “13th” Five-Year Plan for China (grant number 2017YFD060030205), German Government Loans for Sichuan Forestry Sustainable Management (grant number G1403083) and the Study on Species Diversity of large diameter Timber Forest of Pinus massoniana supported by Tianfu Ten Thousand talents Plan of Sichuan Province (1922999002). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.