农林业生态系统的营养元素循环

以泡桐─小麦群落类型为例，调查分析了农林业生态系统营养元素Ｎ、Ｐ和Ｋ的累积、吸收、归还和存留特征及０～８０ｃｍ土层营养元素含量，并以此为依据，分析了全系统的吸收系数、利用系数和循环系数。结果表明，土层中的Ｎ素是限制植物正常生长发育的主要环境因素，保护和促进系统自身枯落物归田并按留量为标准施肥是持续稳定地提高在林系统生产力的根本途径。

咖啡农林生态系统的复杂性

咖啡农林生态系统已经成为研究农林种植与生物多样性保护的典范,热带咖啡种植农林系统包含许多复杂多样的群落,丛林下的荫地咖啡种植到阳地咖啡种植,存在不同遮阴强度的咖啡种植园。本文初步研究咖啡食物网的4个方面:(1)营养相互作用(尤其是脊椎动物和捕食性蚂蚁);(2)性状调节的间接相互作用;(3)竞争和群落组合(主要是鸟类和蚂蚁);(4)群落组合的空间制约。

Phosphorus Transfer and Distribution in a Soybean-Citrus Intercropping System

A mini-plot field experiment was conducted on a loamy clay Oxisol to compare and evaluate P absorption and transfer in plant organs and P movement in soil profile at three P application depths under the soybean-citrus intercropping versus the monoculture using a ^32p tracer technique. Total P absorption （Pt） by soybean and P accumulation （Pa） in soybean organs decreased significantly （P 〈 0.05） under the intercropping in contrast to the monoculture. With intercropping, when ^32p was applied in topsoil （15 cm soil layer）, total ^32p absorption （^32pt） in soybeans was significantly lower （P 〈 0.05）, but when ^32p was applied to deeper soil layers （35 or 55 cm soil layer）, ^32pt in soybeans was significantly greater （P 〈 0.05）. The percentage of P in leaves to total P （Pa/Pt） and 32p in leaves to total ^32p （^32pa/^32pt） for soybean were ≥ 25% and those of root ≥ 12%. When P was applied ia topsoil and 55 cm soil layer, no significant differences were found between intercropping and monoculture for Pt of citrus. The P absorbed by citrus was transferred rapidly to the growing organs of aboveground during the experiment, and the speed of transferring to the growing organs slowed when P was applied to the deeper soil layers. In intercropping, P mobility was heightened in the soil profile, and P in deeper soil layers moved up to topsoil more rapidly.

Emergy Evaluation of a Village Ecosystem in Wolong Nature Reserve in China

Due to historic reasons, there are several human settlements in nature reserves and national parks, which may constitute a threat to biodiversity. Establishment of nature reserves may however generate constraints for development of local communities residing in these reserves. The village ecosystem of Zhuanjinglou Village in Wolong Nature Reserve includes population, farming and livestock (domestic and alpine) and forest ecosystem. An emergy analysis of agro-ecosystem (including the farming and livestock ecosystem) and energy consumption in Zhuanjinglou Village indicates that livestock ecosystem plays an important role in village ecosystem, which may be the source of great pressure on the state of the local environment. The increasing ratio of electricity in energy consumption may play a positive role for environmental conservation. Despite some successful experiences, there are some remaining issues that need to be addressed in the ecological rehabilitation of the village ecosystem.

Coffee Agroforestry with Some Timber Shade Trees： Study on Carbon Stock, Mineral Cycle, and Yield

Coffee cultivation by using shade trees is simple of agroforestry, this system could get better ecosystem service and sustainable agricultural. The aims of this research are to study the possibility of some species of industrial woods as shade trees of Coffea canephora. The research was conducted in Jember, Indonesia （45 m asl., D rainfall type according to Schmidt and Ferguson）, and arranged in split plot design. The main plots were （A） coffee-T, grandis （3 m × 2.5 m ×12 m）, （B） coffee-P, falcataria single row （2.5 m ×6 m）, （C） coffee-P, falcataria double rows （3 m× 2.5 m × 12 m）, （D） coffee-P, falcataria vat. Solomon （3 m× 2.5 m × 12 m）, （E） coffee-M, azedarach （3 m ×5 m ×22.5 m）, （F） coffee-H, macrophyllus （3 m ×5 m ×12.5 m）, and （G） coffee-Leucaena sp. （3 m × 2.5 m） as control. The sub plots were coffee clones, i.e., BP 534, BP 409, BP 936, dan BP 939. Among those timber trees, Leucaena was planted as the alternative shade trees. The result showed that in comparison with control, all of coffee agroforestry system improved carbon sequestration. Total C-stock on （B） was highest, i.e., 1,007 percent to control while the lowest one was （A） 317.44% to control. During one year observation, litter weight of H. macrophyllus was heaviest followed by T. grandis. The lightest litter was obtained from M. azedarach. Based on its mineral contents, litters of T. grandis potentially supplied back nutrients that equaled to total Urea, SP-36, KC1, Dolomite, and Kieserite as much as 574.14 g; P. falcataria 287.57 g, P. falcataria var. Solomon 453.59 g, M. azedarach 450.84 g, H. macrophyllus 877.56 g, and Leucaena 445.12 g per tree per year. Because of heavily fallen leaves of M. azedarach during dry season and conversely too dense shading of H. macrophyllus, bean yield at 4 and 5 years old by using both species were consistently lower than that under T. grandis, P. falcataria and control. At those ages, effect of clone on cherry yield was still not consistent but there was a tendency that BP 939 was most productive, while BP 534 was the less. Its outturn was not influenced by agroforestry system but by clones. The agroforestry pattern influence physical bean characters, more dense of shading, more single bean and empty bean. That bean abnormality also genetically, on BP 939 percentage of round and empty bean was highest while on BP 936 was lowest. It was concluded that coffee agroforestry improve ecology service, but M. azedarach and H. macrophyllus were not appropriate to be used as coffee shade trees. P. falcataria is recommended as an alternative shade tree beside Leucaena sp.

Agroforestry Suggestions Based on Climatic Modeling

Indigenous agroforestry systems have been practiced for centuries in the Himalaya Mountains and adjoining regions.With the increase of climate change associated risks,enhanced understanding of the impact of climate change and related phenomena on the potential distribution of agroforestry is increasingly useful and necessary,for both maintaining and improving yield and ecosystem function.In particular,

A Review of the Contemporary Eco-Agricultural Technologies in China

Eco-agriculture is the principal measure for addressing the environmental issues caused by agriculture and an essential direction for agriculture in the future. Meanwhile, the development of eco-agriculture is inseparable from its technical support. At present, the eco-agricultural technologies commonly used in China can be divided into three categories according to their theoretical basis and practical types: the technologies used to realize the precision input of material resources, the technologies used to improve material circulation efficiency, and the technologies that use the principle of species symbiosis. Although these technologies provide essential support for developing eco-agriculture in China, there are also problems associated with their implementation, such as poor technical application and a low level of industrialization. Therefore, in the future development of eco-agriculture technology in China, the technologies producers should take the actual problems as guide and pay attention to the popularization, industrialization, and application of the technologies.

Synergic Relationship between the Grain for Green Program and the Agricultural Eco-economic System in Ansai County based on the VAR model

Understanding the synergic relationship between the Grain for Green Program(GGP)and the agricultural eco-economic system is important for designing an optimized agricultural eco-economic system and developing a highly efficient structure of an agricultural industry chain and a resource chain.This study used Ansai County time series data from 1995 to 2014,applied vector autoregressive(VAR)models and used tools such as Granger causality,impulse response analysis and variance decomposition,to explore the synergy between the GGP and the agricultural eco-economic system.The results revealed a synergic and reciprocal relationship between the GGP and the agroeconomic system.The contribution of the GGP to the agroecosystem reached 34%,which was significantly higher than either its largest contribution to the agroeconomic system(20.8%)or its peak contribution to the agrosocial system(26.7%).The agroeconomic system had the most prominent influence on the GGP,with a year-round stable contribution of up to 55.3%.These results were consistent with reality.However,the impact of the GGP on the agricultural eco-economic system was weaker than the effect of the agricultural eco-economic system on the GGP.The lag of variable stationarity after the shock was relatively short,indicating that optimal coupling had not formed between the GGP and the agricultural eco-economic system.On the basis of enhancing the ecological functions,we should construct the agricultural industry-resource chain such that it focuses on promoting the effective utilization of resources in the region.In addition,the development of a carbon sink industry can be used to manifest the ecological values of ecological functions.