Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2023, Vol. 44 ›› Issue (5): 1030-1038.DOI: 10.3969/j.issn.1000-2561.2023.05.018

• Ecology & Bibliometrics • Previous Articles     Next Articles

Spatial Distribution and Underground Competition of Roots in Typical Areca Nut-elephant Grass Complex System in Central Hainan, China

ZHOU Hua, XIONG Jiaqian, WU Jinqun, ZHENG Xiaomin, HUANG Hai, CHEN Haihui, YU Xuebiao()   

  1. College of Forestry, Hainan University, Haikou, Hainan 570228, China
  • Received:2022-06-07 Revised:2022-09-08 Online:2023-05-25 Published:2023-06-07
  • Contact: *YU Xuebiao,E-mail:yuxuebiao@163.com

Abstract:

In the agroforestry system, the spatial distribution of the root system of each component determines its competitive ability to the resources in the system, which is an important basis for the design of an agroforestry system. In this paper, the root density and spatial distribution of Areca catechu and elephant grass in the compound system were studied by the zonal layered mining method, and the underground competition index of A. catechu and elephant grass was calculated by the niche overlap formula proposed by Levins. The biomass density of betel nut root (1343.88 g/m3) was 2.41 times that of elephant grass (558.53 g/m3). In the horizontal direction, the biomass density, root length density and competition index of fine roots (0-2 mm), middle roots (2-5 mm) and thick roots (> 5mm) of A. catechu decreased with the increase of the distance between roots and the base of A. catechu trunk. The root biomass density, root length density and competition index of elephant grass increased with the increase of distance, and the distribution was relatively uniform. In the horizontal direction, the root biomass density of A. catechu in 80cm from the trunk of A. catechu was significantly higher than that of elephant grass, and the root biomass density of elephant grass in 120-140 cm was significantly higher than that of A. catechu, but there was no significant difference between them in other distances. The root length density of A. catechu in 20-40 cm was higher than that of elephant grass, but the difference is not significant. The root length density of elephant grass in other horizontal distances was significantly higher than that of A. catechu. Except 20-60 cm from the trunk, the competition index of elephant grass in other areas was higher than that of betel nut. In the vertical direction, the biomass density, root length density and competition index of fine root, middle root, thick root and elephant grass root in 0-20 cm soil layer were significantly higher than those in 20-40 cm soil layer. In the two soil layers, the root length density of A. catechu root system was smaller than that of elephant grass, while the biomass density and competition index of A. catechu root system were larger than that of elephant grass. The results show that although the root distribution of A. catechu and elephant grass overlaps in space, they have their own advantages in a certain area, and neither can form an absolute competitive advantage over the other, thus both can grow healthily in the competition. Therefore, in order to effectively reduce the competition between betel nut and elephant grass, give full play to their respective advantages, and maximize their yield and benefit, we should appropriately increase the planting distance between elephant grass and betel nut trees, and appropriately strengthen the water and fertilizer input in the upper soil in the intercropping area.

Key words: agroforestry system, root system, space distribution, interspecific competition

CLC Number: