High habitat heterogeneity and connectivity promote the diversity and survival of predatory natural enemies in paddy fields
Author of the article:LIU Yu-Fang YANG Guang-Mei ZHAO Wen-Hua YANG Fei XIE Mei-Qi TIAN Teng-Teng
Author's Workplace:College of Life Sciences, Hunan University of Science and Technology, Xiangtan 411201, China;College of Life Sciences, Hunan University of Science and Technology, Xiangtan 411201, China;College of Life Sciences, Hunan University of Science and Technology, Xiangtan 411201, China;College of Life Sciences, Hunan University of Science and Technology, Xiangtan 411201, China;College of Life Sciences, Hunan University of Science and Technology, Xiangtan 411201, China;College of Life Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
Key Words:habitat heterogeneity; habitat connectivity; rice field; predatory natural enemies
Abstract:
[Objectives] To investigate whether habitat heterogeneity
is beneficial to predatory arthropods in rice fields and thereby the natural
control of rice pests, and whether habitat connectivity can help conserve
predatory arthropod populations. [Methods] The diversity and abundance of predatory
arthropods in 20 natural paddy fields with different levels of marginal habitat
heterogeneity and connectivity in a hilly region of central Hunan province were
investigated using community ecology methods. The diversity and abundance of
predatory arthropods was compared between 10 pairs of relatively high
heterogeneity (RHH) and low heterogeneity (RLH) marginal habitat rice fields,
and 10 pairs of relatively high connectivity (RHGC) and relatively poor
connectivity (RHPC) paddy fields. [Results] Species richness in 6 and 7 pairs of
fields was higher in RHH fields than in RLH fields in the early and late rice
growing periods, respectively. Total species richness in RHH fields was 1.13
times higher than that in RLH fields, but this difference was not significant (P>0.05).
The number of individuals per unit area in 8 pairs of fields was higher in RHH
than in RLH fields both in the early and late rice growing periods. The total
number of individuals in RHH
fields was higher than in RLH fields in early rice crops, although this
difference was not significant (P>0.05) it was significantly
different to the number measured in late rice (P<0.05). In 10 and 8
pairs of fields, the ratio of predatory natural enemies to main rice pests (Npi)
was higher in RHH than in RLH fields in both early and late rice crops but
these differences were not significant (P>0.05). Species richness in
9 pairs of fields was higher in RHGC than in RHPC fields in both early and late
rice crops. The number of individuals per unit area in all 10 pairs of fields
was significantly higher in RHGC than RHPC fields in both early and late rice
crops (P<0.01). In the early rice season, the Npi values of all 10 RHGC and RHPC fields were>1, whereas in the
late rice season the Npi values of 8
RHGC fields and 6 RHPC fields were>1. [Conclusion] The number of predatory
natural enemies in RHH fields was significantly higher than in LHH fields.
Habitat heterogeneity and connectivity significantly increases the number of
predatory natural enemies in rice fields, and the potential for ecological
control in such fields is obviously better than in fields with low habitat
heterogeneity and poor connectivity. High habitat heterogeneity and
connectivity increase the numbers of predatory natural enemies in rice fields,
thereby facilitating the natural control of rice pests.