Trend in seasonal amplitude of northern net ecosystem production:Simulated results from IAP DGVM in CAS-ESM2

北方陆地净生态系统生产力(NEP)具有明显的季节变化特征,这是大气CO_(2)季节变化的关键驱动.研究这些碳循环过程并理解潜在的驱动因素是气候研究的一个关键问题.本文利用第二代中国科学院地球系统模式(CAS-ESM2)中的全球植被动态模型(IAPDGVM),研究了1990-2014年北方NEP(40°-90°N)的季节振幅及其变化趋势.在初始化试验的基础上,本文开展了一个控制试验来评估模拟的北方NEP季节幅度的变化趋势,同时开展了三个敏感性试验来研究气候和大气CO_(2)的贡献.结果表明:1990-2014年,模拟的北方NEP季节振幅显著增加,趋势为9.69万吨碳/月/年,这主要是由于最大NEP增加所致.当分别排除CO_(2)施肥效应和气候效应时,上述增加趋势大大减弱.这些显著的减少表明大气CO_(2)和气候变化对北方NEP的季节性振幅有重要影响.尽管模式存在不确定性,但这些结果有利于进一步提升IAPDGVM对陆地碳循环的精确模拟,也为CAS-ESM研究碳-气候相互作用的应用提供了重要参考.

The Dynamics and Driving Force of Farmland Ecosystem Productivity

Based on the experimental data of crop yield, soil water and fertility of a dryland farming ecosystem in northwest China, asystematic analysis is carried out to study the dynamics of dryland farming ecosystem productivity and its limitingfactors. This paper also discusses which of the two limiting factors, i.e., soil water or fertility, is the primary factor and theirdynamics. The result shows that fertility is the primary limiting factor when the productivity is rather low. As chemicalfertilizer input increases and the productivity promotes, water gradually becomes the primary limiting factor. Chemicalfertilizers and plastic film mulching are the two major driving forces that determine the crop productivity and its stabilityin these areas.

How Does the Agricultural Ecosystem Productivity Respond to Climate Fluctuations in the Northern Farming-pastoral Region?

Using meteorological data and mathematical statistics analysis,we take Jungar Banner in the northern farming-pastoral region of China for example,to analyze the fluctuations in the precipitation and average temperature in Jungar Banner during the period 1961-2009.We calculate the NPP of agricultural ecosystem and climatic yield of the main crops in the region during the period 1961-2009,and expound the response of agricultural ecosystem productivity to climate fluctuations in Jungar Banner.Indubitably the climate changes impose great effects on the structure and function of regional ecosystem,and there is a need to take a number of measures to minimize the detrimental effects of climate changes on climatic yield of the main crops.

Succession and Enhancement Mechanism of Ecosystem Productivity in the De-farming Area of the Ecotone Between Agriculture and Animal Husbandry in North China

The succession and enhancement mechanism of the ecosystem productivity with the characteristics ot de-tarmlng in me ecotone between agriculture and animal husbandry in North China was discussed in order to provide an ideaology or a technical basis for maintaining the impetus of ecological restoration and economic development in this region. A case study was applied in combination with the theoretical analysis. The results indicated that the biomass productivity of the de-farming subsystem decreased by 38.4-72.3% compared with that of farming subsystem in the ecosystem. The main function of de-farming subsystem was focused on ecological productivity, it caused the ideal beneficial recycling ‘defarming → planting grass → raising animals → earn money＇ difficult to be realized. With the differentiation of de-farming subsystem, the natural and social resources input to the farming subsystem were accumulated. This laid a basis for the new attributes of economic productivity to be upgraded. The case study indicated that the economic productivity of the ecosystem was increased by 8.85-13.35 times due to re-coupling between the de-farming subsystem and the farming subsystem as well as coupling between microhabitat differentiation and crop production in the subsystems, where the microhabitat differentiation could enrich water and fertilizer in the same field. It was concluded that the important mechanisms to enhance the system productivity in the ecotone between agriculture and animal husbandry of North China included structure rebuilding and opening of the de-farming ecosystem and taking the advantage of complementary cooperative production among different regions under the market economy and rebuilding an open agro-pasture production structure,

Analyzing the spatiotemporal evolution and driving forces of gross ecosystem product in the upper reaches of the Chaobai River Basin

The Chaobai River Basin,which is a crucial ecological barrier and primary water source area within the Beijing-Tianjin-Hebei region,possesses substantial ecological significance.The gross ecosystem product(GEP)in the Chaobai River Basin is a reflection of ecosystem conditions and quantifies nature’s contributions to humanity,which provides a basis for basin ecosystem service management and decision-making.This study investigated the spatiotemporal evolution of GEP in the upper Chaobai River Basin and explored the driving factors influencing GEP spatial differentiation.Ecosystem patterns from 2005 to 2020 were analyzed,and GEP was calculated for 2005,2010,2015,and 2020.The driving factors influencing GEP spatial differentiation were identified using the optimal parameter-based geographical detector(OPGD)model.The key findings are as follows:(1)From 2005 to 2020,the main ecosystem types were forest,grassland,and agriculture.Urban areas experienced significant changes,and conversions mainly occurred among urban,water,grassland and agricultural ecosystems.(2)Temporally,the GEP in the basin increased from 2005 to 2020,with regulation services dominating.At the county(district)scale,GEP exhibited a north-west-high and south-east-low pattern,showing spatial differences between per-unit-area GEP and county(district)GEP,while the spatial variations in per capita GEP and county(district)GEP were similar.(3)Differences in the spatial distribution of GEP were influenced by regional natural geographical and socioeconomic factors.Among these factors,gross domestic product,population density,and land-use degree density contributed significantly.Interactions among different driving forces noticeably impacted GEP spatial differentiation.These findings underscore the necessity of incorporating factors such as population density and the intensity of land-use development into ecosystem management decision-making processes in the upper reaches of the Chaobai River Basin.Future policies should be devised to regulate human activities,thereby ensuring the stability and enhancement of GEP.

Basic Principles of Gross Ecosystem Product(GEP)Accounting

Gross ecosystem product(GEP) is the gross value of all ecosystem products and services provided by ecosystems for human society. In practice, GEP measures the ecosystems’ contributions to human well-being and constitutes one of the core issues in the construction of ecological civilization systems. Currently, GEP accounting faces a series of problems, such as the inconsistency of accounting subjects and a lack of accounting standards,the result of which is the non-reproducibility and weak applicability of accounting results. In this paper, mainstream models for ecosystem service valuation are summarized in a systematic manner. On this basis, eight basic principles are established for screening accounting indicators: biological productivity, human benefits, production territoriality, current increment, actual effectiveness, physical metrizability, data availability, and harmlessness. Next, a series of ecosystem service subjects are identified that need to be excluded from accounting, and the detailed reasons for their exclusion are presented. Finally, three ideas for improving GEP accounting are offered from the perspectives of the relationship between biological production and human production, the circulation-transport relationship and spatial differences, and harms to the ecosystem carrying capacity. The purpose is to provide positive considerations aimed at promoting the socio-economic applications of accounting and to contribute to the scientific quantification of the values of ecological products.

The relative controls of temperature and soil moisture on the start of carbon flux phenology and net ecosystem production in two alpine meadows on the Qinghai-Tibetan Plateau

Aims Variations in vegetation spring phenology are widely attributed to temperature in temperate and cold regions.However,temperature effect on phenology remains elusive in cold and arid/semiarid ecosystems because soil water condition also plays an important role in mediating phenology.Methods We used growing degree day(GDD)model and growing season index(GSI)model,coupling minimum temperature(T_(min))with soil moisture(SM)to explore the influence of heat requirement and hydroclimatic interaction on the start of carbon uptake period(SCUP)and net ecosystem productivity(NEP)in two alpine meadows with different precipitation regimes on the Qinghai-Tibet Plateau(QTP).One is the water-limited alpine steppe-meadow,and the other is the temperature-limited alpine shrub-meadow.Important Findings We observed two clear patterns linking GDD and GSI to SCUP:SCUP was similarly sensitive to variations in preseason GDD and GSI in the humid alpine shrub-meadow,while SCUP was more sensitive to the variability in preseason GSI than GDD in the semiarid alpine steppe-meadow.The divergent patterns indicated a balance of the limiting climatic factors between temperature and water availability.In the humid meadow,higher temperature sensitivity of SCUP could maximize thermal benefit without drought stress,as evidenced by the stronger linear correlation coefficient(R2)and Akaike’s information criterion(AIC)between observed SCUPs and those of simulated by GDD model.However,greater water sensitivity of SCUP could maximize the benefit of water in semiarid steppe-meadow,which is indicated by the stronger R2 and AIC between observed SCUPs and those of simulated by GSI model.Additionally,although SCUPs were determined by GDD in the alpine shrub-meadow ecosystem,NEP was both controlled by accumulative GSI in two alpine meadows.Our study highlights the impacts of hydroclimatic interaction on spring carbon flux phenology and vegetation productivity in the humid and semiarid alpine ecosystems.The results also suggest that water,together with temperature should be included in the models of phenology and carbon budget for alpine ecosystems in semiarid regions.These fi ndings have important implications for improving vegetation phenology models,thus advancing our understanding of the interplay between vegetation phenology,productivity and climate change in future.

Multimodel projections and uncertainties of net ecosystem production in China over the twenty-first century

Ecosystems in China have been absorbing anthropogenic CO2 over the last three decades. Here, we assess future carbon uptake in China using models from phase 5 of Coupled Model Intercomparison Project under four socio-economic scenarios. The average of China's carbon sink from 2006 to 2100 represented by multimodel mean net ecosystem production(NEP) is projected to increase(relative to averaged NEP from 1976 to 2005) in the range of 0.137 and 0.891 Pg C a-1across differentscenarios. Increases in NEP are driven by increases in net primary production exceeding increases in heterotrophic respiration, and future carbon sink is mainly attributed to areas located in eastern China. However, there exists a considerable model spread in the magnitude of carbon sink and model spread tends to be larger when future climate change becomes more intense. The model spread may result from intermodel discrepancy in the magnitude of CO2 fertilization effect on photosynthesis, soil carbon turnover time, presence of carbon-nitrogen cycle and interpretation of land-use changes. For better quantifying future carbon cycle, a research priority toward improving model representation of these processes is recommended.

基于BEPS模型的云南省碳源/汇时空特征及其适用性分析

净初级生产力(NPP)和净生态系统生产力(NEP)是估算陆地生态系统碳源/汇的重要指标,云南为我国碳汇的主要区域之一,开展云南NPP和NEP时空变化特征分析对科学评估陆地生态系统碳源/汇功能,以及开展碳排放交易具有重要意义。基于BEPS模型1981-2019年NPP和NEP产品,采用线性趋势分析、文献对比等方法,研究云南NPP和NEP时空变化特征及其在云南的适用性。结果表明:(1)1981-1999年云南NPP和NEP呈水平波动,2000年后云南NPP和NEP呈明显波动上升趋势,2000-2019年云南NPP高值区域主要分布在西部和南部,而NEP高值区则主要分布在东部和西部局部地区;(2)2000-2019年云南NPP和NEP除西北部部分地区为下降趋势外,其余大部地区为上升趋势;(3)云南NPP峰值出现在7、8月,谷值出现在2月,NEP峰值出现月份与NPP基本相同,但谷值出现月份较NPP滞后1-3个月,6-10月是云南碳汇的主要月份;(4)BEPS模型估算的NPP与目前广泛应用的CASA和遥感模型结果较为一致,时空变化特征与云南生态恢复措施和气候特征吻合,其估算的NEP与陆地生物圈模型(IBIS)模型和中国通量观测研究联盟(ChinaFLUX)碳水通量观测数据较为接近,时空变化大部地区与云南生态恢复措施和气候特征基本吻合,表明BEPS模型在云南具有较好的适用性。

Interannual Variation in Terrestrial Ecosystem Carbon Fluxes in China from 1981 to 1998

A dynamic biogeochemical model was used to estimate the responses of China's terrestrial net primary productivity (NPP), soil heterotrophic respiration (HR) and net ecosystem productivity (NEP) to changes in climate and atmospheric CO2 from 1981 to 1998. Results show that China's total NPP varied between 2.89 and 3.37 Gt C/a and had an increasing trend by 0.32% per year, HR varied between 2.89 and 3.21 Gt C/a and grew by 0.40% per year, Annual NEP varied between -0.32 and 0.25 Gt C but had no statistically significant interannual trend. The positive mean NEP indicates that China's terrestrial ecosystems were taking up carbon with a total carbon sequestration of 1.22 Gt C during the analysis period. The terrestrial NEP in China related to climate and atmospheric CO2 increases accounted for about 10% of the world's total and was similar to the level of the United States in the same period. The mean annual NEP for the analysis period was near to zero for most of the regions in China, but significantly positive NEP occurred in Northeast China Plain, the southeastern Xizang (Tibet) and Huang-Huai-Hai Plain, and negative NEP occurred in the Da Hinggan Mountains, Xiao Hinggan Mountains, Loess Plateau and Yunnan-Guizhou Plateau. China's climate at the time was warm and dry relative to other periods, so the estimated NEP is probably lower than the average level. China's terrestrial NEP may increase if climate becomes wetter but is likely to continue to decrease if the present warming and drying trend sustains.

Quantification of Ecosystem Services Provided by <i>Pterocarpus lucens</i>Lepr. Ex Guill. and Perrott.: Forage Production, Timber and Carbon Sequestration in the Biosphere Reserve of Ferlo (Northern Senegal)

This study aims at quantifying the most important ecosystem services: forage production, timber production and carbon sequestration provided by Pterocarpus lucens to local communities of Ferlo Biosphere Reserve. The results suggested that the ecological structure of Pterocarpus lucens revealed a bell-shaped form with left dissymmetric distribution indicating a predominance of individuals with small circumference and height. A regression using the software Minitab 16, with circumference and the height as explanatory variables, has allowed a development of predictive models for the estimation of the produced forage and the quantification of the timber supplied by one of the most used plant species in Sahelian pastures. Forage production of Pterocarpus lucens was estimated at 178 kg DM/ha. This large value of forage showed the predominance of this species in animal feed in the Sahel. The quantity of wood produced was 545 kg DM/ha while the quantity of above ground sequestered carbon was 325.35 kg of C/ha. Those estimations are interesting in the implementation context of the Ferlo Biosphere Reserve which aims at matching the productive capacity of ecosystems with the needs of local communities.

我国生态产品总值统计核算问题研究

文章在分析GEP概念内涵、分类与核算方法相关研究的基础上,充分借鉴国际统计核算的经验,结合我国GEP统计核算实践,从通用性和可操作性出发,建立了一套与自然资源部门土地利用现状分类相匹配、符合我国实际的GEP核算分类标准,重新划分了森林、草地、湿地、农田、城市、荒漠、海洋等生态系统的分类范围。同时,基于GEP概念、特征、逻辑准则,提出了我国生态产品清单筛选的五个基本原则,讨论了现有GEP实物量和价值量核算方法存在的不足,指出了核算方法选取时需注意把握的问题及未来改进方向。

海洋生态系统生产总值(GEP)核算——以福州市为例

生态系统生产总值(GEP)核算以生态系统提供的产品和服务评估为基础,是对生态系统服务功能的货币化表达,也是衡量“两山”理念实践效果的关键指标。生态系统除产品供给价值和文化服务价值外,其生态系统调节服务是生态系统服务的重要组成部分。论文以生态系统价值核算相关理论和方法为基础,构建了海洋生态系统GEP生态调节服务的核算体系和方法,并对福州市2018年度的海洋生态系统GEP生态调节服务价值进行核算。核算结果表明:2018年,福州市海洋生态系统GEP调节服务价值为43.08亿元,其中气候调节价值为24.32亿元,水质净化价值为2.91亿元,物种保育价值为15.85亿元。气候调节服务是福州市海洋生态系统的主要生态服务类型,其价值占总GEP的56.45%,其次为物种保育价值,占总GEP的36.79%。在福州地区探索建立一套海洋生态系统生产总值核算体系,可为我国其他地区的核算提供参考,有助于正确处理社会经济发展与生态保护之间的关系,为指导地方政府科学保护和利用海洋生态系统提供技术支撑。

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.

数字经济时代农产品营销创新:逻辑、模式与路径

农产品营销创新对于促进农产品产业链扩容提质、发挥联农带农社会效益、推动我国农业农村现代化进程尤为重要。基于创新生态系统理论厘清农产品营销创新的理论逻辑,对创新实践具有重要意义。将创新资源、创新主体、创新技术、创新网络和创新环境等要素相应地演绎为数字资源、数字主体、数字技术、数字社群和数字场景,发现数字经济时代农产品营销创新依托数字资源、数字主体、数字技术、数字社群和数字场景五要素的有机融合、均衡协同和情境共享实现了系统整体最优。以数字资源整合、数字主体联动、数字技术应用、数字社群交互及数字场景共享为依托可以实现农产品全品类营销、全渠道营销、智能化营销、全媒体营销及沉浸式营销五种农产品营销创新模式。因此,可以通过数字资源延伸、数字主体协同、数字技术驱动、数字社群互融和数字场景构建,明确数字经济时代农产品营销创新路径,助力农产品营销拓展产品组合、培育多元主体、构筑信息生态、推进社会商务和深挖文化底蕴。

2001-2020年内蒙古净生态系统生产力格局多时间尺度分析

掌握净生态系统生产力(NEP)时空格局对提高干旱/半干旱地区生态系统功能有重要意义。已有的NEP时空格局研究大多以年尺度开展分析,而NEP在多时间尺度上的特征差异尚不明晰。基于多源遥感、气象和地面实测数据,采用CASA模型、土壤呼吸地质统计模型(GSMSR)和土壤呼吸-土壤异养呼吸(Rs-Rh)关系模型耦合模拟内蒙古2001-2020年NEP,分析其年、季、月多时间尺度时空特征,并探讨8种不同植被NEP的多时间尺度特征差异。结果表明,1)内蒙古年尺度NEP的空间分布格局稳定,从东北向西南递减,这一格局与春夏秋3季及植被生长期的3-10月一致,而冬季植被进入休眠期使得空间差异显著减小。2)内蒙古多时间尺度NEP年际变化趋势有所不同:年尺度上,内蒙古总NEP呈波动上升趋势,年际变化率为C 3.75 Tg·a^(-1);季尺度上,夏季增长趋势最大,占全年增长的41.6%,春秋两季对NEP的增长也起到至关重要的作用,分别占比34.9%和23.3%,冬季对NEP增长贡献非常有限;月尺度上,NEP年内变化与植被生长物候周期较为接近,1月和12月年际NEP为减少趋势,其余月份年际NEP均为上升趋势,其中9月增长趋势最大,占全年增长的19.3%。3)不同植被类型NEP年际趋势存在差异,5种植被类型年NEP呈增长趋势,3种呈下降趋势;草地在季尺度年际变化中均保持增长,在夏季最高,而灌木林在季尺度年际变化中均为降低趋势,夏季降幅最大;月尺度年际变化中灌木林均为降低趋势,1月降幅最大。该研究能够为明晰区域碳循环及改善生态系统功能提供科学依据。

京津风沙源治理区植被固碳能力估算及归因分析

植被固碳能力是陆地生态系统碳汇的基础,可通过净生态系统生产力(NEP)这一重要指标来反映。估算植被固碳能力是生态学和地表生态系统研究领域的共同科学问题,揭示其变化特征及其因素影响对于区域生态系统具有重要意义。以京津风沙源治理区为研究区,估算了2000—2020年京津风沙源治理区NEP,并利用趋势分析法和稳定性分析法等方法分析其时空变化特征,并利用地理探测器探究了影响NEP的自然因素与人类活动因素。结果显示:(1)2020年,京津风沙源治理区的NEP均值为110.09 gC m^(-2)a^(-1),碳汇区面积约为3.591×10~5 km^(2),占总面积的78.80%;(2)2000—2020年,京津风沙源治理区多年平均NEP为77.54 gC m^(-2)a^(-1),年际变化率为4.118 gC m^(-2)a^(-1),总体上呈上升趋势,研究区以NEP明显增加区为主,占比55.16%,主要分布在研究区南部,NEP呈下降趋势地区仅占比0.15%,主要分布在北部干旱草原沙地治理区,呈斑块状分布;(3)不同生态系统NEP从高到低依次为林地、农田和草地,林地固碳作用较强,未来林地固碳潜力较大,草地面积占研究区的70%,其总固碳量远超其他类型且呈增加趋势;(4)影响京津风沙源治理区NEP的主导因素为年降水量,其次,生态工程的实施也是NEP变化的重要影响因素,不同因素对京津风沙源治理区NEP的影响表现为双因子增强或非线性增强。围绕京津风沙源植被固碳能力估算以及影响因素的空间分异性,研究也在一定程度上提出了空间恢复的建议,以期为京津风沙源加强植被固碳能力以及生态修复等决策提供科学依据。

汉中市生态调节服务产品价值变化及驱动因素分析

生态调节服务产品是生态产品总值(GEP)核算的重要组成部分。探究生态调节服务产品价值变化趋势及驱动因素有助于指导GEP提升。文章分析了2011—2021年汉中市调节服务价值变化的驱动机制。结果表明:2021年汉中市调节服务价值为1794.66亿元,其中水源涵养、土壤保持、洪水调蓄、固碳和气候调节合计占比99.9%;2011—2021年,汉中市调节服务价值增加了92.69亿元;自然生态系统面积变化、海拔、植被净初级生产力(NPP)变化是驱动调节服务价值变化的主要因素,能够解释87.9%的价值变化,森林面积和NPP的提升促进了调节服务价值的提高。建议未来积极开展生态保护和修复,提升自然生态系统面积和质量,确保调节服务价值的提升,同时探索生态产品价值实现机制,促进绿水青山向金山银山的转化。

日本构建大学主导型创新生态系统的理论、实践与启示

在知识经济的社会背景下,构建创新生态系统成为大学提高学术生产力和创新能力的重要战略选择。日本遵循“科学技术创造立国”的战略目标,以知识生产、创新网络、生态系统、价值共创为理论基础,利用政策和不同层次路径的实践来构建大学主导型创新生态系统。通过综合研究型大学的跨学科建设,从知识开发上着重增加知识生产存量,建设大学创新生态系统;以产学研的合作为主要推动手段促进知识的流动性,增加知识流量,建设特定领域创新生态系统;以开放式创新合作基地建设作为价值共创手段,从知识的转化中推进知识生产,建设平台创新生态系统。大学主导型创新生态系统建设为日本带来积极的实践效果,具有可持续性、大规模和整体协调性特征,也有一定的局限性。通过日本的经验总结,为中国构建和优化大学主导型知识生产协同创新生态系统带来启示。

三江源国家公园土壤保持实物量计算——基于CSLE模型

土壤保持能力是生态产品价值中可调节产品的重要组成部分,在土壤侵蚀控制及生态环境改善方面具有关键作用。自我国开展国家公园体制以来,其对于三江源地区的土壤侵蚀模数及土壤保持能力的影响尚不明确。对比CSLE与USLE模型及其因子的差异,选取CSLE进行2000年与2020年的土壤侵蚀模数对比研究并计算黄河源区玛多县20年间土壤保持总量。结果表明:1)在研究区中,CSLE模型在区分不同土壤侵蚀模数强度时显著优于USLE模型,其对坡度坡长因子以及生物措施因子的优化计算方法可更精确地评估土壤侵蚀模数。2)从2000年至2020年,玛多县的土壤侵蚀强度得到了较大地改善,约有75%左右区域的土壤侵蚀模数具有明显下降,但仍有小部分区域的土壤侵蚀模数上升,其土壤侵蚀强度加剧。3)玛多县20年间土壤保持总量为1.683×10~6 t,在核算生态产品价值中的土壤保持量时,应以75%的土壤侵蚀模数减少的区域进行计算,而并非采用默认全区土壤均得到了有效保持的USLE公式进行计算。