Spatial and temporal changes of paddy rice ecosystem services in China during the period 1980–2014

The ecological systems services or multi-functionality of paddy rice cultivation are critical to the functioning of the Earth’s life-support system.We estimated the ecosystem services value(ESV)of paddy rice during 1980-2014 across China.The results indicated that the ESV of the paddy field in China showed an upward trend during this period.The share of ESV on CO_(2)sequestration was the highest,followed by ESV on temperature cooling and greenhouse gas(GHG)emission.The yield-scaled ESVs of ZonesⅡ(southern rice-upland crops rotation regions)andⅢ(southern double rice production regions)were similar and significantly higher than the ESVs of ZonesⅠ(northeastern single rice production regions)and IV(Southwest rice-upland crops rotation regions).Between 1980 and 2014,the ESV of each region increased to varying degrees,except for the ESVs of Guangxi,Zhejiang,Fujian,and Guangdong.Such effects suggest the existence of a significant spatial-temporal variation in the total amount,structure,and density of ESV of paddy fields in China,which can further guide the development of future options for the adaptation of healthy rice production in China.

Impacts of the north migration of China＇s rice production on its ecosystem service value during the last three decades (1980-2014)

The ecosystem services value （ESV） of rice system has received increasing attention in agricultural policy decision. Over the last three decades, China＇s rice production presented an obviously trend that moving towards north locations. However, the impacts of this migration on the ESV of rice production have not been well documented. In this paper, we analyzed the change of the ESV of rice production in China under ＂north migration＂ and ＂no migration＂ scenarios during 1980-2014 based on long-term historical data. The results showed that both the positive and negative ESVs of rice production were lower under ＂north migration＂ than under ＂no migration＂ scenarios. The total ESV during 1980-2014 was reduced by 15.8%. ＂North migration＂ significantly reduced the area-scaled ESV since the early 1990s; while its impact on yield-scaled ESV was not significant. The effects of＂north migration＂ on ESV showed great spatial variation. The greatest reduction in total and area-scaled ESV was observed in south locations. While the yield-scaled ESVs of most south locations were enhanced under ＂north migration＂ scenario. These results indicated that ＂north migration＂ has generated adverse effects on the ESV of rice production. An adjustment in the spatial distribution is essential to protecting the non-production benefits of rice ecosystem.

Methane and Nitrous Oxide Emissions from Rice-Duck and Rice-Fish Complex Ecosystems and the Evaluation of Their Economic Significance

Rice-duck （RD） and rice-fish （RF） ecological systems are major complex planting and breeding models of rice paddy fields in southern China. Studying the methane （CH4） and nitrous oxide （N2O） emissions and their economic value from these two ecosystems can provide theoretical and practical basis for further development and utilization of these classical agricultural techniques. CH4 and N2O emissions from RD and RF ecological systems were measured in situ by using static chambers technique. Using global warming potentials （GWPs）, we assessed the greenhouse effect of CH4 and N2O and their economic value. Results showed that the peaks of CH4 emission fluxes from RD and RF appeared at full tillering stage and at heading stage, and the average emission fluxes were significantly （P〈 0.05） lower than that from CK. N2O fluxes remained low when the field is flooded and high after draining the water. Compared with CK, the total amount of N2O emissions was significantly （P〈0.05） higher and slightly lower than those from RD and RF, respectively. In 2006 and 2007, the total greenhouse effect of CH4 and N20 from RD and RF were 4 728.3 and 4 611 kg CO2 ha^-1, 4 545 and 4 754.3 kg CO2 ha^-1, respectively. The costs of greenhouse effect were 970.89 and 946.81 RMB yuan ha^-1, and 933.25 and 976.23 RMB yuan ha^-1, respectively, which were significant lower than those from CK （5 997.6 and 5 391.5 RMB yuan ha^-1）. Except for the environment cost of CH4 and N2O, the economic benefits from RD and RF were 2 210.64 and 4 881.92 RMB yuan ha^-1; 3 798.37 and 5 310.64 RMB yuan ha^-1, respectively, higher than those from CK. Therefore, RD and RF complex ecological planting and breeding models can effectively decrease and control CH4 and N2O emissions, and they are two of the effective strategies to reduce greenhouse gases from rice paddy fields and contribute in alleviating global warming. Thus, their adoption is important to the environment together with their economy benefits.

STUDY ON RESIDUES OF ^(14)C-CARBOFURAN IN MODEL RICE-FISH ECOSYSTEM

Residues of 14C- carbofuran were studied in model late- rice ecosystem (LRE) and early- rice ecosystem (ERE). The treatment consisted of two rates of the pesticide (1x) and 2.5x). At day 56 after application, 7.3% (1x) and 2.9% (2.5x) of the pesticide and its degradative products remained in the water of the LRE, and 1.8% (1x) and 2.4% (2.5x) of them remained in the water of the ERE. At harvest, 37.5% (LRE) and 24.0% (ERE) of the pesticide applied were detected in the upper layer of the soil; and 40.6% (LRE) and 26.9% (ERE) remained in the lower layer of the soil. The residues in the rice plants increased at the first stage, reached maximum levels during day 14 to 28 after application, and decreased thereafter. At harvest, residues in the stems and leaves in the two treatments (1x and 2.5x) were 3.91μ g/g and 7.78μ g/g (LRE) and 5.04 μg/g and 17.29 μ g/g (ERE) respectively. Residues in the ears were about 1/8 to 1/12 of that in the other parts of the plants. The pesticide residues in fish bodies in both experiments were also determined.

THE FATE OF ^(14)C-FENITROTHION IN RICE-FISH MODEL ECOSYSTEM

The fate of fenitrothion in rice- fish ecosystem was studied using C- fenitrothion (14C- F) labelled at methoxyl and two application rates. The fenitrothion in water disappeared quickly, only 8 and 11 ppb in two treatments at harvest were detected respectively. Most of 14C-F in soil existed in upper layer and that in plants appeared in shoots. The extractable residues in cargo rice were 0.36 and 0.58 ppm in two treatments respectively. 14C- residues (14C- R) were concentrated in bones, next viscera, meat and scales. Total 14C-R in meat were 0.92 and 1.77 ppm at harvest. Comparing two treatments, the residue dynamics of fenitrothion in water, soil, plants and fish were similar. 14C- R in water and soil after harvest affected the rice- fish ecosystem in the next season. However, the extractable 14C- R in cargo rice, soil and water were very low. Fenitrothion 14C- fenitrothion Rice- fish Model

基于TOP-RICE模型嘧菌酯·噻呋酰胺4%展膜油剂稻田水溢出对水生生态系统风险评估研究

为评估嘧菌酯·噻呋酰胺4%展膜油剂在我国稻田水溢出对水生生态系统的风险,本研究依据中华人民共和国农业行业标准NY/T 2882.2—2016《农药登记环境风险评估指南第2部分:水生生态系统》,采用TOP-RICE暴露模型分别单独评估了嘧菌酯和噻呋酰胺2种有效成分稻田滴撒方式应用时水溢出对水生生态系统的风险。其中,TOP-RICE初级暴露模型中有我国连平和南昌2个水稻-地下水暴露场景,每个场景都对分蘖期和拔节期进行分别评估。分析结果显示,嘧菌酯·噻呋酰胺4%展膜油剂中的嘧菌酯按照申请的良好农业规范(GAP)使用,生物富集风险可接受,初级风险评估对无脊椎动物(急性)和无脊椎动物(慢性)风险不可接受,但经中宇宙研究后,在连平和南昌2个场景点,均为拔节期用药对无脊椎动物的风险可接受,但分蘖期用药对无脊椎动物的风险不可接受;嘧菌酯·噻呋酰胺4%展膜油剂中的噻呋酰胺按照申请的GAP使用,生物富集带来的风险可以接受,经初级风险评估风险均可接受。在忽略2种有效成分相互间作用时,初步认为嘧菌酯·噻呋酰胺4%展膜油剂在我国稻田拔节期按照GAP要求施用时水溢出对水生生态系统的风险可接受,但应避免在分蘖期用药,以免其中的有效成分嘧菌酯对水生无脊椎动物产生不良影响。

Seasonal and Interannual Variations of Carbon Exchange over a Rice–Wheat Rotation System on the North China Plain

Rice-wheat （R-W） rotation systems are ubiquitous in South and East Asia, and play an important role in modulating the carbon cycle and climate. Long-term, continuous flux measurements help in better understanding the seasonal and interannual variation of the carbon budget over R-W rotation systems. In this study, measurements of CO2 fluxes and meteorological variables over an R-W rotation system on the North China Plain from 2007 to 2010 were analyzed. To analyze the abiotic factors regulating Net Ecosystem Exchange （NEE）, NEE was partitioned into gross primary production （GPP） and ecosystem respiration. Nighttime NEE or ecosystem respiration was controlled primarily by soil temperature, while daytime NEE was mainly determined by photosythetically active radiation （PAR）. The responses of nighttime NEE to soil temperature and daytime NEE to light were closely associated with crop development and photosynthetic activity, respectively. Moreover, the interannual variation in GPP and NEE mainly depended on precipitation and PAR. Overall, NEE was negative on the annual scale and the rotation system behaved as a carbon sink of 982 g C m 2 per year over the three years. The winter wheat field took up more CO2 than the rice paddy during the longer growing season, while the daily NEE for wheat and rice were -2.35 and -3.96 g C m-2, respectively. After the grain harvest was subtracted from the NEE, the winter wheat field became a moderately strong carbon sink of 251-334 g C m-2 per season, whereas the rice paddy switched to a weak carbon sink of 107-132 per season.

Past, Present and Future Perspectives of Rice Production in Tanzania

Cultivated rice (Oryza sativa L. and Oryza. glaberrima) is one of the most important food crops in the world. World rice production has increased three times since the green revolution. However, climate change and global warming effects as well as ever increasing world population will require the world to produce more rice without increasing area under rice production in order to meet those demands. The best option to overcome these challenges includes adoption of climate-smart technologies and sustainable solutions to rice production. Rice was probably introduced in Tanzania over 1000 years ago by Asian traders during trade contacts between Asia and East Africa Coast through Indian Ocean. Rice cultivation had been restricted to coastal area until 19th century when it started spreading to interior areas of Tanzania. During colonial period (1880s-1960s), the emphasis was to produce cash crops as raw materials for industrialized world. After independence production of rice increased significantly. Currently, rice is the second most important food crop in Tanzania after maize and Tanzania is the leading producer of rice in East African countries. It ranks 4th and 22nd in Africa and World respectively in terms of rice production. In this paper, the rice history, ecosystems, challenges and future perspective for sustaining rice production in Tanzania is reviewed.

粮食分功能区城镇化对稻田生态净价值的影响研究

基于2010年—2019年中国30个省域层面稻田生态系统的数据,运用面板回归分析了各粮食功能区城镇化对稻田生态净价值的影响。结果表明:在粮食主产区、产销平衡区与粮食主销区,城镇化对稻田生态净价值有显著的正向影响,且城镇化对粮食主销区的稻田生态净价值存在显著的单重门槛效应。结合粮食功能区城镇化对稻田生态净价值影响的差异性,因地制宜提出了稻田生态系统可持续性保护与粮食安全保障的政策建议。

水稻生态系统碳密度空间分布及其影响因素研究

水稻生态系统是陆地生态系统的重要组成部分,在碳循环中起着十分重要的作用,且在小尺度区域中,碳密度空间分布上也会存在不小的差异,故本研究旨在区域尺度上分析水稻生态系统碳密度空间分布差异并探究造成差异的原因。通过实测临安区水稻地上部分、根系以及土壤的碳密度,同时结合临安区地理数据,使用空间自相关分析方法分析各乡镇碳密度空间分布差异,并对差异性作具体分析,探究其影响因素。结果表明,临安区水稻生态系统碳密度空间上呈现一定的自相关性及聚集性,临安中部地区水稻生态系统碳密度值较低,西部地区水稻土壤碳密度值较高且呈聚集性,东部地区水稻作物碳密度值较高且呈聚集性。究其原因,在区域尺度上地形因素对水稻生态系统的碳密度有一定影响;同时,由于中部地区的过度施氮肥导致土壤性质破坏,故土壤氮密度也是影响碳密度的一个重要因素。本研究对指导当地水稻农业生产以及促进水稻农业发展具有重要意义。

水稻生长季CO_(2)通量的时间动态和影响因子研究

为了明确长三角地区稻麦轮作生态系统中水稻生长季CO_(2)通量的多时间尺度变化特征,量化环境因子对农田CO_(2)通量变化的贡献度,拆分环境因子的直接影响和间接影响,该研究利用涡度相关观测系统进行了2年CO_(2)通量的连续观测,分析了辐射类、温度类、水汽类和风速对CO_(2)通量的影响。结果表明:稻麦轮作生态系统在水稻生长季是一个二氧化碳汇,2020、2021年水稻生长季的总固碳量分别为396.3、491.9 g/m^(2)(以C计);CO_(2)通量也有明显的日变化,呈现出“U形”和“V型”的单峰曲线,吸收峰值出现在第200~250天。在不同时间尺度上,影响CO_(2)通量的主控因子始终是光合有效辐射;但随时间尺度的增加,各个因子贡献度的差异逐渐减小。饱和水汽压差也是影响CO_(2)通量的重要因子,它与光合有效辐射的交互作用会抑制彼此对CO_(2)通量的直接贡献。

中国稻田登记噻虫嗪单剂的水生生态风险评估

为评估第二代新烟碱类杀虫剂噻虫嗪对水生环境的潜在风险,本文采用TOP-RICE模型,选取高浓度、短时间间隔和低浓度、长时间间隔2种施药方法,对我国在水稻上已登记的有效的施用方式为“喷雾”的噻虫嗪单剂品种进行暴露浓度预测。运用风险商值法对噻虫嗪进行水生生态风险评估。结果显示,截至2023年10月,近3年我国水稻上登记的有效噻虫嗪单剂共383种,主要剂型为水分散粒剂、可湿性粉剂、悬浮剂、种子处理悬浮剂、悬浮种衣剂、颗粒剂等,其中,水分散粒剂占比最大,占总量的28.72%。TOP-RICE模型预测结果显示,水分散粒剂、可湿性粉剂、悬浮剂3种噻虫嗪制剂产品在水稻上施用后,预测环境浓度范围为0.2300~29.2464μg·L^(-1),通过物种敏感性分布(SSD)曲线的绘制得到噻虫嗪对水生生物急性生态风险阈值(HC 5)为16.09μg·L^(-1),慢性HC 5为2.096μg·L^(-1),并且以溪流摇蚊为代表的大部分无脊椎动物对该杀虫剂较为敏感。结合风险商值(RQ)值的计算得出这3种剂型噻虫嗪对水生生态环境存在一定的威胁,在目前登记施用条件下,噻虫嗪可湿性粉剂的预测环境浓度较大,对水生生态系统的风险大于其他剂型。本研究由于通过模型完成,并且代谢物数据并不足,实验数据偏保守,结果存在一定的不确定性。

水稻种植环境治理对乡村生态系统的影响与可持续发展策略

水稻种植是全球粮食安全的关键环节,其环境治理和可持续发展策略对保障国家粮食安全、应对气候变化挑战至关重要。合理的水稻种植环境治理措施有助于减少农业生产对自然生态环境的负面影响,提高农业生产效率、增加农民收入,促进乡村生态系统的可持续发展。从种植技术、废弃物利用、生态补偿、经济发展四个层面提出了水稻种植环境治理的可持续发展策略,为乡村振兴战略的实施提供了科学依据和实践指导。

江苏省稻虾综合种养生态系统服务价值评估及演变分析

对稻虾综合种养生态系统服务价值开展评估,可为稻虾综合种养模式推广、可持续发展及生态补偿提供可靠的理论依据。本文通过构建稻虾综合种养生态系统服务价值评估指标体系,利用市场价值法、替代工程法、当量因子法等多种经济方法,估算江苏省稻虾综合种养生态系统服务价值,并探寻其演变规律。研究结果表示:2012—2022年间,江苏省稻虾综合种养系统生态价值从37.34亿元增长至273.27亿元,呈现先降低再升高的变化趋势。在各单项服务价值中,产品供给服务价值居于主导地位,到2022年占比达89%;土壤有机质积累、固碳释氧服务功能均呈现先降低再升高的趋势。

稻蛙生态种养模式碳足迹评价

【目的】开展稻蛙生态种养模式碳足迹系统性研究,为该模式的可持续发展提供科学依据和优化建议。【方法】采用生命周期评价法,对常规水稻种植(Traditional rice monoculture,TR)、绿色稻蛙种养(Green rice-frog coculture,GF)和有机稻蛙种养(Organic rice-frog coculture,OF)模式进行碳足迹评价。【结果】GF和OF的单位面积碳足迹分别为5985.20和5632.99 kg CO_(2)e·hm^(−2),相比TR分别降低5.98%和11.51%,单位利润碳足迹分别下降45.10%和45.87%,单位营养密度碳足迹分别下降14.63%和12.17%。GF和OF净生态系统经济效益提高了50%以上,其中GF的高达71.77%。与TR相比,GF的产量差异不显著,OF的产量降低了16.73%;GF和OF的CH4排放分别增加了58.13%和131.18%,N2O排放分别降低了41.06%和63.12%;GF和OF具有更高的全球增温潜势和温室气体排放强度,其中,OF的影响更为显著。GF和OF中,有机物料如紫云英、菜籽饼和有机肥的投入表现为净碳固定效应。碳足迹构成和敏感性分析显示,TR的碳足迹构成中温室气体排放(57.07%)和化肥施用(32.88%)占比较高;OF的碳排放和固定均高于GF,CH4排放和尼龙防护网使用对GF和OF的贡献最大。不确定性分析表明,GF和OF的单位面积碳足迹分别为5907.29和5647.25 kg CO_(2)e·hm^(−2),低于TR,变异系数小于7.5%。【结论】稻蛙共作模式(GF和OF)相较于TR模式具有更低的碳足迹以及更突出的碳固定效应和环境友好等特点,为气候变化背景下我国水稻产业的绿色低碳发展提供了新的科学依据。

稻田系统养分循环利用对土壤肥力和可持续生产力的影响

基于12a田间定位试验结果,研究了在不同化肥配施条件下,有机养分循环利用对亚热带红壤稻田生产力和土壤肥力的影响。结果表明:①施用化肥是实现水稻高产的必要条件。在连续不施肥情况下,水稻产量维持在5.6t·hm-2的水平,投入化肥N(229kg·hm-2)、N-P(39kg·hm-2)和N-P-K(162kg·hm-2)之后,产量分别提高到了6.6、7.9和9.0t·hm-2。农田系统有机养分循环利用能进一步提高水稻产量,但产量增益随NPK配施程度提高而降低。②在不施肥或只施N肥的情况下,有机物循环利用能显著降低水稻产量的年际变异系数,而在NP或NPK配施基础上的有机物循环利用则不能显著提高水稻的稳产性能,说明适量和平衡地提供水稻所需的营养元素是水稻稳产的物质基础,至于这些养分是来自化肥或有机肥源并不重要。红壤稻田早稻的稳产性受施肥模式的影响较大,施磷肥是降低早稻产量波动、提高稳产性能的最重要条件。③连续12a不施肥对土壤有机质含量没有显著影响,施化肥NPK处理的土壤有机质含量呈现出不稳定的上升趋势,而有机物循环利用能显著提高土壤有机质含量和土壤养分的生物有效性。通过有机物养分资源的循环利用,可有效降低当前稻田化肥的高投入水平,减轻环境污染压力,实现农田生态系统生产力的高效可持续发展。

4种生态类型稻区节肢动物群落的基本组成与结构特征分析

根据在浙江富阳、河南郑州、江苏句容和湖南长沙的连续田间调查，稻田节肢动物群落的组成依生态学上的营养关系分为植食类（害虫）、捕食类和寄生类（天敌）、以及腐生类和水生类（与水稻关系不甚密切，但可作为天敌的猎物）等。进一步分析显示，不同稻区的节肢动物群落的种－丰盛度关系适于用对数正态分布（Ｌｏｇｎｏｒｍａｌｄｉｓｔｒｉｂｕｔｉｏｎ）模型描述，单一作物生长季节中取样总计少于１０个个体的物种所占比例为４３．７６％－７１．９１％。不同类群的相对丰盛度因地而异，且可是水生类的摇蚊（富阳早稻田）、白背飞虱和褐飞虱（富阳晚稻、句容、长沙）、黑尾叶蝉（郑州）或腐生类的弹尾虫（句容）。多样性（以Ｎ＿１表示）的高低顺序为郑州（２８．５６）＞富阳晚稻（２２．４３）＞句容９１（１１．０８）＞富阳早稻（６．４３），句容９２（６．８０），和长沙（６．７２）。极丰盛种所包括的个体数占总个体数量的比例在６９％－８０％之间，具有普遍性的丰盛种有猎物类的褐飞虱、白背飞虱、蚊类、弹尾虫以及捕食类的狼蛛、黑肩绿盲蝽和尖钩宽蝽等，构成了稻田节肢动物群落组成及功能作用的主体。

稻鸭、稻鱼共作生态系统CH_4和N_2O温室效应及经济效益评估

【目的】稻鸭、稻鱼共作生态系统是中国南方稻作区两种主要复合种养模式。研究稻鸭、稻鱼共作生态系统中CH4和N2O排放产生的温室效应并对其经济价值进行评价,旨在为进一步开发利用稻田综合利用模式提供理论基础和实践依据。【方法】采用静态箱技术,研究稻鸭、稻鱼共作生态系统CH4和N2O排放规律,并运用增温潜势对稻鸭、稻鱼共作生态系统CH4和N2O排放的温室效应及经济效益进行估算。【结果】在水稻生长期间,稻鸭、稻鱼共作系统中CH4排放峰值均出现在分蘖盛期和抽穗期,其平均排放通量均显著(P<0.05)低于常规淹水稻田;N2O的排放通量在稻田淹水期间保持较低值,而在稻田落干后迅速升高。养鸭显著(P<0.05)提高了稻田N2O的排放,养鱼降低了稻田N2O的排放。2006和2007年稻鸭、稻鱼处理CH4和N2O排放产生总温室效应分别为4728.3、4611.0kgCO2·hm-2和4545.0、4754.3kgCO2·hm-2,其温室效应成本分别为970.89、946.81 yuan/hm2和933.25和976.23 yuan/hm2,明显低于CK的5997.6和5391.5 yuan/hm2。除去CH4和N2O排放产生温室效应的环境成本,采用稻鸭、稻鱼生态种养技术的经济效益分别比常规稻田增加2210.64、4881.92yuan/hm2和3798.37、5310.64 yuan/hm2。【结论】稻鸭、稻鱼共作能有效的抑制稻田温室气体排放并显著降低其温室效应。因此,稻鸭、稻鱼共作是减少温室气体排放的有效措施之一,具有较好的推广价值。

湿地稻——鸭复合系统中田间杂草的变化规律

为了克服水稻田大量施用化学农药除草的弊端,对中稻和晚稻的稻鸭共生田中杂草种群的消长动态进行系统研究.结果表明,稻田养鸭对杂草的控制效果为98.5%～99.3%,比施用化学除草剂的效果高6.9%～16.1%.放鸭田不仅消除了杂草危害,而且省工、省药、增产、增收,是一项一举多得的生物除草技术.

水稻害虫及其天敌在生境间迁移的监测方法和原理

通过对实例的剖析研究，较全面地探讨稻田生态系统中水稻害虫及其天敌在生境间迁移的监测方法和有关原理。具体分析了不同采集、诱集和标记方法在稻田节肢动物迁移活动研究中的适用性、优点和限制条件。