Effects of Land Use Change on Eco-environment in Hilly Area of Central Sichuan Basin——A Case Study of Yanting County, Sichuan Province

With the artificial alder and cypress mixed forest being planted, there has been a marked land use change since 1970s' in Hilly Area of Central Sichuan Basin, China. Data from meteorological observations or posts operated over long time, measurement and calculation of NPP (net primary production) and biomass of biological community, and analysis of soil organic matter content show that the artificial alder and cypress mixed forest has outstanding eco-environmental effect: adjusting local climate, raising soil fertility, alleviating menace of drought, and raising NPP and biomass of biological community. It is very beneficial for improving ecological environment to afforest artificial alder and cypress mixed forest in populous Hilly Area of Central Sichuan Basin, China. Key Words: land use/land cover change (LUCC); eco-environmental effect; Hilly Area of Central Sichuan Basin; the artificial alder and cypress mixed forest

Farmer's Adaptive Strategies on Land Competition between Societal Outcomes and Agroecosystem Conservation in the Purple-soiled Hilly Region,Southwestern China

The worldwide extension and intensification of farming during the last century has led to ecosystem degradation and caused a series of environmental problems.Conservation of ecosystem services in agricultural regions has been implemented by top-down government actions or initiated by resilience scientists in the developed countries,but little attention was paid in the developing countries,especially in some remote mountainous regions.The present paper presents a case study showing how local farmers obtained both maximal societal outcomes and agroecosystem conservation interests in the absence of distinct boundaries between agricultural and protected ecological areas in the densely populated purple-soiled hilly region of southwestern China.The local community(Yanting County) has developed a mosaic agricultural-forestry-fishery-stock breeding system with spatially targeted land uses,diverse agricultural productions and multiple ecological partnerships.It indicates that the local farmers have hereditarily perceived sound strategies on maximizing sustainable societal outcomes and optimizing tradeoffs among macro-market,state policy,new technological facility and ecological reinforcement.

Analysis of the track system in bumpy unstructured hard road environment by vibration test

The complex terrain environment in the hilly land directly affects the operational reliability of agricultural robots.In order to study the impact of road irregularity on walking chassis vibration,the 3CYLZ-750 remote-controlled weeding machine which is applied to orchards was taken as the object of study,and the rear roller was selected as the object of observation to reveal the rules under which the vibration of the track chassis changes as there is a sudden change in road surface elevation.A column-type test-to-pass method based on unit excitation was proposed in this study.The excitation behavior and action process were analyzed by category.A critical acceleration prediction model was built and verified by virtual simulation and hard road surface excitation testing.The results showed that at the forward velocity of 0-2.5 km/h and exciter height of 20-100 mm,the vertical vibration acceleration of the target roller was significantly affected by Track Contact Point Centrifugal Acceleration(TCPCA).As TCPCA increased,the change rate of vertical vibration acceleration decreased,reaching a minimum of[−13.8,28.8];as TCPCA decreased,the vertical vibration acceleration tended to increase positively at a maximum variation range of[−13.3,42.2].The measured and simulated macroscopic change rules were consistent with the theoretical analysis,further verifying the correctness of variable extraction,and providing a research basis for the accurate modification and improvement of the model.The research conclusions can lay a theoretical foundation for analyzing the walking reliability of the track chassis,and provide a design basis and technical support for the development of a tracked agricultural robot chassis for the hilly land in the future.