[Relationship between changes of herbaceous plants and Oncomelania hupensis snail distribution under walnut forest of inhibition of snails in mountainous regions of Yunnan Province].
OBJECTIVE
To explore the relationship between the changes of herbaceous plants and Oncomelania hupensis snail distribution under the walnut forest of inhibition of snails in mountainous regions of Yunnan Province.


METHODS
The experimental field was established at Sanying Village of Eryuan County, Yunnan Province, where the "Flourishing Forest and Controlling Snails Project" was implemented. The different stand ages (2, 4, 6, 8, 10 years)of walnut forest in experimental groups were selected based on the method of space replacing time, and the non-stocked land was served as a control group. The growth of forest, change of snails, number, biomass, overcast, height of the herbaceous plant and the soil moisture were investigated.


RESULTS
The crown closure of 6-year-old walnut forest of inhibition of snails was 0.65. There were 11 species of herbaceous plant belonging to 11 genera, 6 families in 10-year-old forest and its crown closure was 0.77. Compared with the control group, the numbers of families, genera, and species of the 10-year-old forest were decreased by 64.71%, 69.44%, and 77.08%, and the biomass, overcast, and height of it decreased by 12.63%, 19%, and 22.18%, respectively. The soil moisture content (0-20 cm) monthly changes were increased obviously with the increase of stand age. There were no snails besides the control group and 2-year-old walnut forest. Compare with the control group, the occurrence rate of frames with living snails in the 2-year-old walnut forest was decreased by 50%, which was 1.25%. The density of living snails was decreased by 60.16%.


CONCLUSIONS
The construction of walnut forest of inhibition of snails in mountainous regions of Yunnan Province are suitable for controlling the growth of herbaceous plants and altering the environment of snails. If the coalescence intercropped with crops is carried out, it is not only beneficial to the construction of good ecological environment, but also improves the utilization efficiencies of land, light, and thermal resource, and the income of peasants.
Desert Ecosystem Station in Yuanmou County, State Forestry Administration of China, Research Institute of Resources Insects, Chinese Academy of Forestry, Kunming 650224, China.
Chun-Hua
CH
Zhang
Desert Ecosystem Station in Yuanmou County, State Forestry Administration of China, Research Institute of Resources Insects, Chinese Academy of Forestry, Kunming 650224, China.
Fang-Yan
FY
Liu
Desert Ecosystem Station in Yuanmou County, State Forestry Administration of China, Research Institute of Resources Insects, Chinese Academy of Forestry, Kunming 650224, China.
Guang-Fu
GF
Liu
Desert Ecosystem Station in Yuanmou County, State Forestry Administration of China, Research Institute of Resources Insects, Chinese Academy of Forestry, Kunming 650224, China.
Yong-Yu
YY
Sun
Desert Ecosystem Station in Yuanmou County, State Forestry Administration of China, Research Institute of Resources Insects, Chinese Academy of Forestry, Kunming 650224, China.
Guo-Yong
GY
Tang
Desert Ecosystem Station in Yuanmou County, State Forestry Administration of China, Research Institute of Resources Insects, Chinese Academy of Forestry, Kunming 650224, China.
Kun
K
Li
D000818:Animals; D018533:Biomass; D002681:China; D003710:Demography; D017753:Ecosystem; D031324:Juglans / Q000254:growth & development*; D012908:Snails / Q000254:growth & development*; D014197:Trees / Q000254:growth & development*