川中丘陵区农田生态系统太阳辐射及土壤热通量数据集(2005-2021年)

太阳辐射是地表生态系统的主要能量来源,是生态系统维持本身正常运转和发展的原始动力;地表层土壤热通量是地表能量平衡的重要参数之一。四川盐亭农田生态系统国家野外科学观测研究站(简称盐亭站)是国家布局在亚热带四川盆地农业生态区的唯一农田生态系统监测野外站。该区域具有优越的光、热、水资源,非地带性土壤紫色土广泛分布,形成亚热带湿润季风气候与非地带性紫色土的最佳农业组合,农耕活跃,是四川盆地农业的主体区域。本研究基于盐亭站综合气象观测场Vaisala(芬兰)自动气象观测系统,经过数据采集、处理、数据质量控制与评估,集成2005-2021年紫色土典型农田生态系统太阳辐射和土壤热通量数据集,太阳辐射监测包括总辐射、反射辐射、紫外辐射、净辐射和光合有效辐射。数据集包含5个EXCEL文件,有各类辐射的时值、日值和月值观测及统计数据,数据量32.7 MB。本数据集可为生态系统生产能力评估、应对气候变化等方面的研究提供数据支持。

Seasonal and Annual Variations of CO_2 Fluxes in Rain-Fed Winter Wheat Agro-Ecosystem of Loess Plateau, China

To accurately evaluate the carbon sequestration potential and better elucidate the relationship between the carbon cycle and regional climate change, using eddy covariance system, we conducted a long-term measurement of CO 2 fluxes in the rain-fed winter wheat field of the Chinese Loess Plateau. The results showed that the annual net ecosystem CO 2 exchange （NEE） was （-71.6±5.7） and （-65.3±5.3） g C m-2 y-1 for 2008-2009 and 2009-2010 crop years, respectively, suggesting that the agro-ecosystem was a carbon sink （117.4-126.2 g C m-2 yr-1）. However, after considering the harvested grain, the agro- ecosystem turned into a moderate carbon source. The variations in NEE and ecosystem respiration （R eco ） were sensitive to changes in soil water content （SWC）. When SWC ranged form 0.15 to 0.21 m3 m-3, we found a highly significant relationship between NEE and photosynthetically active radiation （PAR）, and a highly significant relationship between R eco and soil temperature （T s ）. However, the highly significant relationships were not observed when SWC was outside the range of 0.15-0.21 m3 m-3. Further, in spring, the R eco instantly responded to a rapid increase in SWC after effective rainfall events, which could induce 2 to 4-fold increase in daily R eco , whereas the R eco was also inhibited by heavy summer rainfall when soils were saturated. Accumulated R eco in summer fallow period decreased carbon fixed in growing season by 16- 25%, indicating that the period imposed negative impacts on annual carbon sequestration.

NUMERICAL CLASSIFICATION OF REGIONAL STRUCTURE OF AGRO-ECOSYSTEM IN GUANGDONG

On the basis of 'The Statistical Data of Guangdong Province in 1981' and the 14 selected original variables, 107 counties and suburbs in Guangdong are classified. In the classification, cluster analysis is applied, and the cluster hierarchy of the agro-ecosystem is achieved with a computer. According to output level, planting structure, and input level of energy, there is an evident regionalism in the agro-ecosystem of Guangdong, which presents approximately concentric circles centralized by Guangzhou City.

Agro-ecosystem Emergy Evolution and Trend in Hunan Province

Using the emergy analysis method,we conduct trend analysis of changes in the total emergy,input and output structure,various emergy indicators of agro-ecosystem in Hunan Province during the period 1999-2008.The results show that during the study period,total emergy input basically remained stable,but the emergy input structure was constantly optimized,of which the input of non-renewable industrial assistant emergy increased by 38.4%,from 4.00E +22 sej to 5.53E +22 sej,and the input of renewable organic emergy declined from 1.32E +23 sej to 1.20E + 23 sej;total emergy yield and yield efficiency of this system were promoted dramatically,and in 2008,the total emergy yield reached 1.69E +23 sej,increasing by 23.8% as against that in 1999,the net emergy yield ratio rose from 0.79 to 0.96;since the environmental loading ratio also tended to rise constantly,from 1.12 to 1.79,the sustainability index of this system also experienced the slow downward trend,from 0.71 to 0.54,always less than 1,indicating that the agriculture in Hunan Province is the high consumption-driven ecosystem in general,with obvious features of extensive development.

Enhancing the Social and Natural Capital of Canadian Agro-Ecosystems through Incentive-Based “Alternative Land Use Services” (ALUS) Programs: Recurring Themes and Emerging Lessons

Alternative Land Use Services (ALUS) is an incentive-based program established in Canada to pay farmers for their voluntary delivery of ecosystem services (ES). All seven ALUS programs across the country were examined using a standardized case-study approach based on site visits, reading internal documents, attending program meetings, and engaging in semi-structured interviews with program administrators, participating farmers, and advisory board members. Direct content analysis was used to highlight recurrent themes and emerging lessons in relation to the salient particulars of program physical location, administration framework, delivery of ES, and development and receipt by communities. Our three major findings are: 1) Overall, ALUS has been judged by participants to be a very successful program, whose strength is that it is completely voluntary, non-permanent, and readily adaptable to each location’s environmental conditions, economic funding base, and cultural milieu. 2) One serious shortcoming of all ALUS programs is a general lack of quantifiable data on their ability to increase ES. Instead, environmental benefits are either assumed or based on the idea that the areal extent of enrolled land is the sole measure of its environmental worth. 3) It may be that the social impact of ALUS is its greatest success. In this regard, for farmers, it is the process of engaging in land-use decision making and the recognition of their role as environmental stewards that is a bigger motivation for participating in an ALUS program than the modest financial incentives which they receive.

Livelihood Diversification of Farm Households and Its Impact on Cultivated Land Utilization in Agro-pastoral Ecologically-vulnerable Areas in the Northern China

The relationship between livelihood diversification of farm households and cultivated land utilization has become a core research topic related to global environmental change.Agro-pastoral ecologically-vulnerable areas face challenges such as insufficient ecosystem conservation,low agricultural production,and weak economies.In this study,215 farm households from Zhengxiangbai Banner,Taibus Banner,and Duolun County of Inner Mongolia were surveyed.The sustainable livelihoods framework of the United Kingdom(UK)Department for International Development(DFID)was used to measure the livelihood capital of these farm households.A one-way analysis of variance(ANOVA)was applied to examine the differences in the livelihood capital of different types households,and a correlation analysis was applied to analyze its impact on cultivated land utilization.Results showed that households with non-farming activities accounted for 64.7%of the total surveyed households,and non-farming employment was becoming more prevalent.Physical and financial capital was the driving factors for livelihood diversity.Each livelihood capital had key factors that affected household farmland use behaviors,such as the age of householder,the labor ratio,proportion of income,farmland scale,number of machines,and these had a significantly positive or negative influence on farmland use.Full-time farming households were more likely to transfer the land into cultivation and invest more labor,while non-farming households with high income were likely to transfer farmland out and invest more money to develop efficient farming or improve the employment skills.The results of this study suggest that policymakers need to fully consider livelihood changes of local households.It is effective to strengthen labor training,create farmland market and improve the efficiency of farmland utilization.We hope to achieve a win-win scenario to improve local economies and ecosystem conservation.

基于Agro-IBIS模型的新疆农田生态系统净初级生产力时空动态及其对气候变化的响应模拟

为系统地了解干旱区农田生态系统碳动态及其对气候变化的响应,笔者利用基于过程的新型全球动态植被模型(Agro-IBIS)模拟了1979—2009年间新疆农田生态系统净初级生产力(NPP)的时空变化,并通过相关性分析揭示农田NPP对不同气候因子和CO_2浓度变化的响应。结果表明,1979—2009年新疆农田NPP平均值为723.78 g C/(m^2·a),总碳储量约为237.15 Tg C,净农田生态系统碳交换量(NEE)年平均值为-63.36 g C/(m^2·a),并总体上呈碳汇特征。对新疆农田NPP的空间变化而言,除了在天山地区绿洲农田NPP出现较小幅度的减少外,总体变化呈逐步增加趋势。31年来,新疆农田年度NPP总量与年均气温的相关性比,与降水量的相关性较高。说明灌溉对新疆干旱区绿洲田生产力的影响远大于自然降水。经验证,Agro-IBIS模型对于新疆农田生态系统碳收支的模拟结果合理,可以为中国西北干旱区农田生态系统固碳潜力的模拟预测和科学制定区域碳管理政策提供科学依据。

Sustainability issues in agro-ecology: Socio-ecological perspective

In the recent past there has been concern to address the declining trends and deteriorating ecological elements and their functions in productive agricultural landscapes. The efforts to revive the ecological functions needs multiple scale approach, which include scientific understanding, time dependent restorative activities and incorporation of wisdom of the stakeholders. Conservation initiatives linked to precision farming is an apt mechanism to minimize the loss of natural resources of agricultural landscapes to maintain the complex stabilizers of ecological functions. Such an effort must address the scientific evaluation of the farm as “ecologically sustainable unit” with due consideration to social construct at local to regional level. Sustainability indices can be useful tools for evaluating the farms to isolate degradative factors and identify ecologically conservative practices. This review will analyze certain inter-linked concepts relevant to address the sustainability issues in agro-ecology at the interface of socio-ecological perspective.

Non-use value assessment for wetland ecosystem service of Hongxing National Nature Reserve in northeast China

By the contingent value method, we studied the non-use value of wetland ecosystem service of Hongxing National Nature Reserve （HNNR） in Heilongjiang Pro- vince, northeast China. The proportion of respondents willing to pay （WTP） for protection of HNNR was 63 %. The WTP ratio was affected by geographical area, contact nature, personal preferences, and familiar degree of the respondents. The WTP value was affected by age, education level and career of the respondents. The mainly reasons for people rejecting to pay for protecting HNNR were ＂I am not familiar to HNNR＂ and ＂I had no capacity for additional spending because of low income＂. Weighted average individual WTP value was CNY 59.26 Yuan ind.^-1 year^-1 for all the respondents with WTP. The total non-use ecosystem service value of HNNR was CNY 1430 million Yuan in 2013. The heritage value was highest followed by existence value and option value. From the high ecosystem service value in HNNR, it is very important to construct nature reserve for protecting natural ecosystems and human sustainable use of natural resources.

The Shift of Traditional Agroecosystems in the in Eastern Arc Catchments of Tanzania

The purpose of this study was to identify the drivers of the shift of traditional agro-ecosystems and their implication on catchment resources management of Eastern Arc Catchments of Tanzania. Lower Mngeta and Upper Zigi water catchments are situated within Eastern Arc Mountains of Tanzania. Household questionnaire, key informant interviews and focus group discussion were used for collecting primary data. The findings indicated that most of the participants (85.9% and 90.4% in Lower Mngeta and Upper Zigi catchments respectively) depend on subsistence rain-fed agriculture for their livelihoods. However, there are significant changes in production as a result of land fertility deteriorating and negative climatic changes (seasonal shift). This has become a major challenge for most of the farmers. To cope with agro-ecosystem dynamics, farmers in the study areas use both traditional and modern strategies as illustrated in the results section. While tradition always reported to be inexpensive, some modern agro-ecosystem practices reported to cause siltation, killing of fish and herbal plants, easy rotting of seeds (for maize) and bad aroma (for rice)in spite of having a high rate of return. It was also reported that depletion of traditions and norms of conduct, accelerated by multi-cultural interaction from immigrants, have led to deterioration of traditional agriculture practices. Moreover, arrival of agriculture companies and introduction of spice farming was reported to have caused manpower imbalance, unequal distribution of natural resources and less diversity of indigenous plants. The study concludes that communities are much into economic opportunity derived from agro-ecosystem than stewarding it. The study recommends that the effort restoring catchment ecosystem should come from both traditional and modern strategies so as to harmonize and accommodate environmental, economic and traditional values.

Measurement on the Harmony Coefficient of Agro-eco-economic System in the Arid Region

On the basis of the present research progress of ecological agriculture,we take Minle County and Linze County located in the middle reaches of Heihe River as the typical research units.Based on the rural social and economic data during the period of 2000-2010,theory and method of mathematical statistics are used to establish the measure theory and model of agro-eco-economic system harmony coefficient,including efficacy function,function of harmony coefficient,harmony coefficient and level of harmony coefficient.Based on the actual situation of research region,evaluation indicator system of agro-eco-economic system is established and measurement is carried out.Results show that the regional agro-eco-economic system in research region was in a serious imbalance in 2000-2013.The harmony coefficient of Minle showed a slight rise from 2000 to 2004,and then presented a fluctuating decline.Its rank of harmony coefficient experienced serious imbalance-extreme imbalance-moderate imbalance-low imbalance-serious imbalance-high imbalance.At the same time,the similar tendency happened in Linze County.The measuring results of subsystem in 2000-2013 further indicated that except that the harmony coefficient of economic subsystem in Minle County and Linze County was moderate and high,the ecological subsystem was at Level II and Level III,and social subsystem was at Level IV and Level III,in high and low imbalance status.Finally,several recommendations were put forward for optimizing agro-eco-economic system.

中国典型农业生态系统的固碳减排现状、影响因素及减排措施

农业生态系统既是温室气体的重要贡献者之一,也是固碳端,在固碳减排上发挥着重要作用。在“碳达峰”和“碳中和”的背景下,农业生态系统的固碳减排潜力巨大。本文主要综述了中国典型农业生态类型中主要温室气体的来源、固定途径及其影响因素,讨论了农业生态系统固碳减排的现有研究成果、减排潜力以及存在问题,总结了推动整个农业生态系统固碳相关领域的研究,展望了新的研究方向和探索途径。为中国进一步固碳减排、农业可持续发展,尽快实现“双碳”目标提供重要理论参考。

中国北方农牧交错区生态系统服务价值时空变化特征及驱动力分析

为探究区域生态系统服务价值(Ecosystem services value,ESV)时空变化特征及其驱动因子,本研究基于1990—2020年七期土地利用数据,采用当量法估算北方农牧交错区的生态系统服务价值,在GEE云平台与ArcGIS软件的支撑下,分析其时空变化特征,并利用地理探测器模型揭示影响其变化的关键驱动因子。北方农牧交错区30a间草地面积增幅最大,建设用地呈逐年增长的趋势,林地与荒地面积减少,耕地与水域面积基本保持不变,土地利用空间分布格局基本稳定,土地利用方式的转化主要发生在耕地、林地与草地之间;北方农牧交错区年均ESV总量呈降低趋势,以林草地和水域提供调节服务为主,其次为支持服务、供给服务和文化服务,研究区ESV的空间分布与土地利用空间分布格局高度关联;北方农牧交错区ESV空间分异性受多种因素共同驱动,单因子表现为NDVI解释力最高,双因子表现为夜间灯光与NDVI交互作用最强。

基于DSS的1978-2005年中国区域农田生态系统氮平衡

该文建立了养分平衡决策支持系统,并利用该系统对中国国家及分省层次上的农田生态系统氮养分平衡情况进行了研究。研究表明:1)从1978到2005年,全国氮素养分盈余量不断上升,从1978年的1054.66×104t一直上升到2005年的2867.12×104t,平均年增量约为64.7×104t;2)区域之间氮素盈亏量存在着显著差异。粮食主产区的省份如山东、河南和四川的养分氮盈余量一直都较高,而西部省份如新疆、西藏等养分氮盈余量较低。中国粮食主产区农田生态系统氮素平衡呈现出持续盈余且逐年上升的态势,显示出以化肥氮为主体的氮素养分投入量已经长时间高于作物的需求量,这些盈余的氮素养分在农田中累积,并通过多种途径进入到水体及大气环境中,不但造成了氮素化肥的浪费,更会对环境造成较大的压力。

兰州土壤-蔬菜系统铅污染特征及全钾速效钾与pH对其富集特性影响

通过野外调查取样与实验测定相结合的方法,对兰州市农业生态系统土壤-蔬菜体系49个样点进行研究,分析探讨了研究区蔬菜与土壤的铅污染水平以及蔬菜铅富集效应特性。结果表明:①蔬菜种植地土壤铅平均含量为26.30 mg.kg-1,合格率为93.62%,在不同县区存在显著差异,其大小顺序为红古区>榆中县>永登县;②蔬菜铅平均含量为0.59 mg.kg-1,合格率为60.78%,在不同县区存在显著差异,其大小顺序为永登县>榆中县>红古区;③蔬菜铅富集系数为(1.69±2.99)%,永登县蔬菜的铅富集能力显著高于榆中县和红古区,不同种类蔬菜铅富集能力在不同县区具有差异性;④土壤全钾除与白菜和甘蓝有正相关性以外,与其他蔬菜均为负相关性,其中与白菜、番茄、土豆显著相关,与胡萝卜为极显著相关;⑤土壤速效钾与各种蔬菜的铅富集能力均为正相关性,其中与胡萝卜、甜菜、甘蓝为显著正相关,与番茄、土豆、菜花为极显著正相关;⑥土壤pH值与胡萝卜、甜菜铅富集系数呈显著负相关,与菜花呈极显著负相关。研究表明,兰州市不同蔬菜产区的各类蔬菜对土壤铅的富集具有明显的差异性,同时不同形态的钾元素及土壤pH值对蔬菜铅富集能力具有显著的影响。

北方农牧交错区农业生态系统生产力对气候波动的响应--以准格尔旗为例

气候变化对区域生态系统结构和功能有重大影响。以中国北方农牧交错区的准格尔旗为例,利用气象和《统计年鉴》数据,采用数理统计方法分析准格尔旗1961—2009年降水量、平均气温的波动特征,计算出该地区1961—2009年农业生态系统NPP值和主要农作物的气候产量,论述了准格尔旗农业生态系统生产力对气候波动的响应。结果表明:(1)降水量和平均气温的年际、年内波动均显著。(2)准格尔旗农业生态系统生产力呈现阶段性地波动上升趋势。排除社会、科技等影响,气候生产力对气候波动表现出较强的敏感性,是作物气候生态适应的结果。(3)中国北方雨养旱作区,粮食气候产量受降水量年际波动(特别是7、8月)显著影响;谷子、糜黍、玉米、薯类、大豆和油料等农作物的气候产量与降水量年际波动呈显著正相关;谷子、糜黍的气候产量与生长季降水量年内波动呈显著负相关。集水型生态农业是北方农牧交错区生态环境友好的农业发展模式。(4)谷子、糜黍、薯类、大豆和油料等农作物的气候产量与6、7、8月平均气温年际波动呈显著负相关;生长季平均气温年内波动对谷子、糜黍、大豆和油料等农作物的气候产量有显著负面影响。因此,需要综合采取工程、生物和农业措施,将气候变化对主要农作物气候产量的不利影响降到最低。

农林业系统沙兰杨-小麦、玉米群落类型氮、磷、钾营养元素循环的研究

农林业系统沙兰杨-小麦、玉米群落类型N、P、K营养元素循环研究结果表明:在整个群落中,元素N和P发生损亏,K基本平衡。在植物组分库和枯落物库中,元素N、P、K均发生累积;在土壤库中,元素N、P和K均发生亏损。土壤表层(0—20cm)N的含量是限制农作物正常生长发育的主要环境因子。土壤库中有效N和速效P的含量是限制沙兰杨正常生长发育的主要环境因子。群落的年输入输出量大,枯落物少,营养元素在各组分间的循环量大等是该群落类型营养元素循环的重要特性。

山地-绿洲-荒漠的系统耦合是祁连山水资源保护的关键措施

祁连山发育的水系,是河西走廊山地、绿洲、荒漠复合生态系统赖以生存的基础,却由于生产的压力和全球气候变化处于危机之中。林、草、苔藓、灌木结合是保护祁连山水源的关键,既能够维持水源的数量,还能保护水源地的环境。河西走廊的山地、绿洲、荒漠是一个整体,任何一个子系统出问题,都会造成整个复合农业系统的灾难,根据草地农业生态系统4个生产层的理论,调整复合农业系统的生产结构,是发展山地-绿洲-荒漠系统耦合的捷径,将构筑祁连山水源保护的农业系统基础。这种模式在我国西北内陆,乃至世界干旱地区具有示范意义。

西北内陆区农业生态系统资产负债研究--以甘肃省凉州区为例

本文以甘肃省凉州区为例,分析了其绿洲农业区1949～2005年生态系统可持续发展能力的资产负债动态变化,探究西北内陆区绿洲农业生态系统可持续发展能力,预测其可持续发展程度及未来趋势。结果表明:甘肃省凉州区农业生态系统的资产在1949～1970年为急速下降阶段,由14.14下降至4.93,下降65.13%;1970年以后为缓慢增长阶段,至2005年增长到33.33。负债自1949年以来,一直呈负增长趋势,由?0.91增长至?56.67,负增长了61.27倍。净资产也呈明显的先降后升趋势,1949～1970年,以环境资产占优势,表现为资产盈余,且呈递减趋势,至20世纪70年代初期,净资产接近于0;1970年以后,以负债量占优势,表现为资产赤字,且呈递增趋势,尤其在20世纪80年代后期以后,几乎呈直线上升,但自2000年以后,负债量有所减少。2005年凉州区农业生态系统可持续发展能力资产负债分布表的结果表明,生存、发展、环境、社会和智力5大支持系统的共30项源指标中有10项列入"资产"栏目,17项列入"负债"栏目,凉州区净资产为?23.34。本研究结果表明,凉州区农业生态系统处于不可持续状态,但其生态环境的自然资产库存量已经开始增加,人类再次向可持续发展方向迈进。

放牧压力对中国北方农牧交错带生态系统健康的影响

中国北方农牧交错带生态系统敏感脆弱、不稳定,其健康状况受多种因素影响,其中以放牧为代表的人类经济活动影响显著。高强度放牧是造成草地退化的重要原因,草地退化又是影响草原生态系统健康的关键因素。利用归一化植被指数和牲畜量量化放牧压力,并选取合理的模型探究放牧对于中国北方农牧交错带生态健康的影响,确定合理的放牧强度和策略,以实现草畜平衡和区域可持续发展。基于“活力-组织力-弹性-生态服务”(VORS)模型,构建起包括自然、社会等多方面的指标体系,评估了2000—2015年北方农牧交错带的生态健康系统水平,并采用Moran′s I探讨放牧压力和生态系统健康指数的空间相关性,并从普通最小二乘法、地理加权回归模型、时间加权回归模型和时空地理加权回归模型选择最优回归模型,揭示放牧压力对于生态系统健康的影响机制。结果表明:(1)2000—2015年放牧强度格局高值区域主要为内蒙古草原地区,低值区域主要为陕西高原地区。(2)2000—2015年中国北方农牧交错带的生态系统健康指数呈现上升趋势,区域整体处于亚健康状态和一般健康状态。(3)全局双变量Moran′s I结果显示在2000—2015年呈现负相关影响关系,但影响力度在变小。(4)多种回归模型相比较,GTWR模型表现最优。2000—2015年,正向驱动空间集中在内蒙古、辽宁以及山西省区县;负向驱动空间集中在陕西省、甘肃等区域,同时影响强度持续增强。研究通过不同区县、不同的草原的反应状况,提出放牧政策的不同实施建议,致力于实现草原资源的可持续利用和生态系统的持续健康。