Ecosystem Services of Grazed Grasslands in the Flooding Pampa

The Flooding Pampa grasslands are the last remnant of the Rio de la Plata grasslands in Argentina.Anthropo-genic interventions have led to severe degradation and,as a result,the ecosystem services provided by the grass-lands are declining,in terms of provisioning,regulating,and supporting services.We synthesized the existing literature on the ecosystem goods and services provided by these grasslands under grazing in different conditions and conservation status.We found that plant and animal diversity and primary production are the most studied ecosystem services,while climate regulation,water supply,nutrient cycling,meat production and erosion control,in that order,are less studied.Cultural services are under-researched.Continuous grazing and glyphosate spraying are the main drivers of grassland degradation.Controlled grazing and conservative stocking rates have been shown to reverse degradation and demonstrate that livestock production is compatible with ecosystem conserva-tion by maintaining regulating and provisioning services.As these management strategies are poorly integrated,improving their implementation will require important changes in farmers’decisions and the development of policies that create the economic conditions for this to happen.Research is needed to understand the conditions that prevent the knowledge generated from being transferred to producers and translated into practices that would improve the provision of ecosystem services.

Improving remote sensing-based net primary production estimation in the grazed land with defoliation formulation model

Remote sensing(RS) technologies provide robust techniques for quantifying net primary productivity(NPP) which is a key component of ecosystem production management. Applying RS, the confounding effects of carbon consumed by livestock grazing were neglected by previous studies, which created uncertainties and underestimation of NPP for the grazed lands. The grasslands in Xinjiang were selected as a case study to improve the RS based NPP estimation. A defoliation formulation model(DFM) based on RS is developed to evaluate the extent of underestimated NPP between 1982 and 2011. The estimates were then used to examine the spatiotemporal patterns of the calculated NPP. Results show that average annual underestimated NPP was 55.74 gC·m^(-2)yr^(-1) over the time period understudied, accounting for 29.06% of the total NPP for the Xinjiang grasslands. The spatial distribution of underestimated NPP is related to both grazing intensity and time. Data for the Xinjiang grasslands show that the average annual NPP was 179.41 gC·m^(-2)yr^(-1), the annual NPP with an increasing trend was observed at a rate of 1.04 gC·m^(-2)yr^(-1) between 1982 and 2011. The spatial distribution of NPP reveals distinct variations from high to low encompassing the geolocations of the Tianshan Mountains, northern and southern Xinjiang Province and corresponding with mid-mountain meadow, typical grassland, desert grassland, alpine meadow, and saline meadow grassland types. This study contributes to improving RS-based NPP estimations for grazed land and provides a more accurate data to support the scientific management of fragile grassland ecosystems in Xinjiang.

Effects of Non-protein Nitrogen Supplement on Growth Performance of Graze Cattle

[Objective] The experiment was conducted to investigate the growth performance of graze cattle fed on non-protein nitrogen （NPN） supplement. [ Method] The experiment was conducted in late spring and early summer before grazing. Thirty Chinese SimmentaI-Taihang taxa bulls at the age of 9-10 months weighing 150-170 kg were divided into the control group, experimental group 1 and experimental group 2, 10 in each group, Each cattle in the experimental group 1 fed on the basal diet supplemented 1.0 kg cornmeal every day. Each cattle in the experimental group 2 fed on the basal diet supplemented 1.0 kg cornmeal and 0.25 kg NPN supplement every day. Those in the control group were fed on the basal di- et. The experiment was performed for 100 d. [Result] The average daily gain of the experimental group I was 217 g larger than that of the control group, while the average daily gain of the experimental group 2 was 429 g larger than that of the control group. The differences in the average daily gain were significant between the three groups. [ Conclusion ] The growth performance of cattle grazed in northern slopes was obviously improved by supplementing a small amount of concentrate in feed. The improvement was more remarkable if a small amount of NPN supplement was also added in feed.

Effects of Feces on Spatial Distribution Patterns of Grazed Grassland Communities

Animals excrete feces during grazing. The uneven distribution of feces causes a spatial heterogeneity in grassland communities. In this study, we attempted to clarify the effects of feces on spatial distribution patterns of plant species. A field study was conducted on four grasslands each grazed by a single cow. These four grasslands were defined as Poa pratensis （Kentucky bluegrass） dominated grassland without feces （PoF-）, Poa pratensis dominated grassland with feces （PoF＋）, Zoysia japonica Steud. （Japanese lawngrass） dominated grassland without feces （ZyF-）, and Zoysia japonica Steud. dominated grassland with feces （ZyF＋）. A 50 m line that transects 100 equally spaced quadrats （L-quadrats） was drawn on each of the four grasslands. Each quadrat was 0.50 m × 0.50 m in size and consisted of four equal-area cells of 0.25 m ×0.25 m （S-quadrats）. The occurrences of all plant species were recorded in each S-quadrat. The binomial distribution （BD） and beta-binomial distribution （BBD） were used to represent the variation in spatial patterns. The BBD provided a significant description of the frequency distribution of plants per quadrat. A power law was used to calculate the spatial heterogeneity of each species together with the community heterogeneity. The results revealed that the plants on each of the four grasslands were aggregatively distributed. The ZyF＋ exhibited greater spatial heterogeneity than the ZyF-due to the uneven deposition of feces by cows grazing on the grasslands. Additionally we also found that the feces had effect on the heterogeneity inZyF＋ and did not have effect in PoF＋.

Analysis of Characteristics of Grazed Artificial Pastures in the South of Guizhou

＂Ryegrass, orchard grass, Festuca arundinacea and Trifolium repens＂ were researched in Dushan County, Guizhou Province, in order explore grass characteristics by different grazing methods in seasons. The results show that grass community height in different groups was of little differences（P0.05）; the group of moderate grazing in spring, summer and autumn dominated in grass cover; grass density showed insignificant variations among different treatment groups（P0.05） and in the groups of heavy grazing in spring and autumn and moderate grazing in summer and of moderate grazing in spring, summer and autumn, grass community density was higher compared with the other groups（P0.05）; as for above-ground biomass, the group of moderate grazing in spring and autumn and heavy grazing in summer and of moderate grazing in spring, summer and autumn dominated.

Grasshopper Species-Area Relationship on Ungrazed and Overgrazed Grasslands

The species richness and abundance of rangeland grasshoppers were investigated at 6 sites of ungrazed and overgrazed pastures in Inner Mongolia during the autumn of 1994.The ungrazed sites supported higher richness and density of grasshoppers than the overgrazed sites.The effects of overgrazing and ungrazing on the species-area relationships of grasshoppers were directty measured.The grasshopper assemblages from the 6 sites differed significantly in the intercept or in the slopes of their species-area regressions.The greater intercept and slope values of their species-area regression were found in grasshopper assemblages on ungrazed sites.In contrast to species-area relationship regression,the species increase rate with individual number was more rapid at overgrazed sites.Implications for conservation are discussed.

Response of understory vegetation over 10 years after thinning in an old-growth cedar and cypress plantation overgrazed by sika deer in eastern Japan

Background： Forest management strategies such as thinning have long been used to enhance ecosystem functions, especially in plantations.Thinning in plantations with high deer density, however, may not yield a desired increase in understory vegetation because deer graze on germinating plants after thinning.Here, we examine the changes in understory vegetation after thinning in plantations that have been overgrazed by sika deer to provide insight into the effects of thinning on ecosystem functions such as soil conservation and biological diversity.Methods： We conducted our survey in the Tanzawa Mountains of eastern Japan.We surveyed the change in understory vegetation within and outside of three deer exclosures on a single slope with three levels of understory vegetation cover： sparse（1%, exclosure ＂US＂）, moderate（30%, exclosure ＂MM＂）, and dense（80%, exclosure ＂LD＂） over10 years after a 30% thinning of an old-growth cedar and cypress plantation which was overgrazed by sika deer.Results： Understory vegetation cover, biomass and species richness increased within and outside the ＂US＂ and＂MM＂ exclosures after thinning, and biomass was greater within than outside the exclosures at 10 years after thinning.Unpalatable species dominated both ＂US＂ and ＂MM＂ exclosures before thinning, and trees and shrubs dominated within the exclosures over time after thinning.In contrast, unpalatable, grazing-tolerant, perennial,and annual species increased outside the ＂US＂ and ＂MM＂ exclosures.No noticeable changes were observed within and outside the ＂LD＂ exclosure when compared with the ＂US＂ and ＂MM＂ exclosures.Conclusions： Our results suggest that thinning a stand by 30% based on volume resulted in an increase in understory vegetation cover mainly composed of both unpalatable and grazing-tolerant species in a plantation forest where understory vegetation is sparse or moderate and sika deer density is high.We emphasize that establishing deer exclosures or controlling deer is essential to maintaining similar understory vegetation both within and outside exclosures.

Seed rain and soil seed bank compensatory roles on Nassella tenuis(Phil.)Barkworth seedling recruitment in ungrazed and grazed sites

In semi-arid lands,vegetation is distributed in shrub patches immersed in a less vegetated interpatch matrix.Grazing affects perennial grass seed bank through a decrease in seed rain and an increase in seed predation and soil compaction.Nevertheless,some species with anchorage mechanisms in their seeds might overcome this,such as Nassella tenuis(Phil.)Barkworth.This is an important species in grazing paddocks because it has an intermediate palatability and its relatively tolerant to grazing.These characteristics allow N.tenuis to increase its abundance in grazed sites.Our objective was to assess how grazing affects the key palatable species from seeds to seedlings:i.e.,seed rain,soil seed bank,and seedling recruitment in different microsites along a windward-leeward transect across shrub canopy.We hypothesized that:(1)the negative effects of grazing on N.tenuis fructification are reflected in its seed rain,soil seed bank,and seedling recruitment,especially in interpatches;(2)Nassella tenuis seed rain reduction,soil compaction by cattle in grazed sites,and removal of seeds by wind decrease its soil seed bank,especially in microsites exposed to the predominant wind;and(3)the decrease in N.tenuis soil seed bank and cover increase in annual species in grazed sites have negative effects on its seedling recruitment,especially in microsites exposed to predominant wind.We placed seed traps,collected soil samples,and monitored seedling recruitment in different locations around shrub canopy to address our hypotheses.Also,we established a manipulative experiment in which we sow N.tenuis seeds and followed its recruitment in different microsites.We compared the seed rain,soil seed bank,natural seedling recruitment,and sown seeds recruitment of N.tenuis between grazed and ungrazed sites.We analyzed differences between microsites along a windward-leeward transect across shrubs patches.Seed rain and soil seed bank had the same density in patches and interpatches both in ungrazed and grazed sites.But seed rain was higher,and soil seed bank was lower in ungrazed sites than in grazed sites.Almost all under-canopy microsites showed greater soil seed bank abundance and natural seedling recruitment in ungrazed sites.Sown seeds recruitment was the same between grazed and ungrazed sites,but it showed protective effects of shrubs in leeward microsites under grazed sites.As a conclusion,seed rain and soil seed bank are complementary under grazed sites.

Virally-Mediated Versus Grazer-Induced Mortality Rates in a Warm-Temperate Inverse Estuary (Spencer Gulf, South Australia)

We investigated the seasonal dynamics of flow cytometrically-defined populations of viruses, heterotrophic bacteria, and the picoeukaryotic and prokaryotic phytoplankton at three sites in the temperate oligotrophic inverse estuary of Spencer Gulf (South Australia). We consistently identified two sub-populations of viruses, three sub-populations of heterotrophic bacteria, one population of picoeukaryotic phytoplankton and two populations of prokaryotic phytoplankton (cyanobacteria Prochlorococcus and Synechococcus). Both the cytometric community composition and the abundance of viruses, heterotrophic bacteria and both prokaryotic (Synechococcus and Prochlorococcus) and eukaryotic picophytoplankton were consistent with previous observations conducted in South Australian continental shelf waters. Noticeably LDNA bacteria (i.e. inactive or dormant cells) were consistently significantly the most abundant group of heterotrophic bacteria (totaling from 29% to 68% of total bacterial abundance) and were up to 10-fold more abundant than that previously reported in South Australian continental shelf waters, including the nearby Saint Vincent Gulf. These results suggest an overall low activity of the microbial community, and are consistent with previous evidence that LDNA cells may play a greater role in heterotrophic processes than HDNA cells in oligotrophic waters. In an attempt to further assess the qualitative and quantitative nature of the mortality of these organisms, we used a specific dilution assay to assess the relative contribution of viruses and microzooplankton grazers to the mortality rates of heterotrophic bacteria, and picoeukaryotic and prokaryotic phytoplankton. We consistently reported site-specific, population specific and sea-son-specific viral lysis and grazing rates of heterotrophic bacteria and the picoeukaryotic and prokaryotic (cyanobacteria Prochlorococcus and Synechococcus) phytoplankton across sites and seasons. Specifically, both viral lysis and micro-zooplankton grazing rates of heterotrophic bacteria were consistently relatively low across sites and seasons, even though their seasonality suggested an overall dominance of grazing over viral lysis in both summer and winter. In contrast, no seasonality is found in either lysis or grazing rates of prokaryotic and eukaryotic picophytoplankton, which are comparable to previous observations conducted in oligotrophic waters, suggesting the mortality dynamics of these populations is similar to those encountered in other oligotrophic waters. The observed patterns of mortality rates of heterotrophic bacteria and both prokaryotic and eukaryotic picophytoplankton are consistent with the low chlorophyll concentration and production previously observed in the waters of the Spencer Gulf.

人工混播草地土壤丛枝菌根真菌对轮牧的响应

为探究轮牧对人工混播草地生态系统中植被群落及土壤丛枝菌根(arbuscular mycorrhiza,AM)真菌群落的影响机制,以宁夏盐池县人工混播草地为试验对象,采用单因素随机区组设计,设置T1(无芒雀麦+新麦草+紫羊茅+苜蓿+菊苣)、T2(垂穗披碱草+新麦草+早熟禾+苜蓿+鹰嘴紫云英)、T3(扁穗冰草+新麦草+蒙古冰草+苜蓿)3种混播组合模式,并通过Illumina高通量测序和生物信息学分析,开展轮牧影响下3种人工混播草地土壤AM真菌群落差异性研究,分析人工混播草地生态系统中植被-土壤-AM真菌群落的相互作用关系。结果表明:连续2年轮牧对植被群落生物量产生了显著影响,与轮牧第1年相比,豆科植被群落的相对重要值降低,但禾本科植被群落的相对重要值分别增加了51.16%、81.25%和33.33%。土壤AM真菌中球囊霉属和类球囊霉属为优势属;与轮牧第1年相比,连续轮牧2年后,T1处理的土壤AM真菌群落Chao 1指数较第1年显著降低了12.35%,T3处理的土壤AM真菌群落Chao 1指数、香农-维纳指数、均匀度指数和物种数较第1年分别提升了20.73%、12.80%、7.69%和31.16%(P<0.05),说明T3处理的土壤AM真菌群落对轮牧的响应更加敏感。随轮牧年限增加,T1与T2处理的土壤AM真菌群落组成相似性增加,T1与T3处理的土壤AM真菌群落组成相似性差异较大。连续轮牧2年后,土壤养分对AM真菌群落丰富度的作用强度减弱,但植被群落多样性和植被群落生物量对AM真菌群落丰富度及其组成的作用强度增强;驱动AM真菌群落变化的环境因子由土壤有效磷(p=0.006)和碱解氮(p=0.016)转变为植被群落生物量(p=0.036)。综上所述,不同类型人工混播草地植被群落和土壤AM真菌群落对轮牧表现出不同的响应特征,其中以T3混播组合处理的效果较好。

草地放牧饲养要素分析

饲养牲畜是草地放牧的目标,放牧饲养牲畜是草地饲草资源利用的最有效途径。放牧饲养要素包括草地生产率、适宜载畜率、饲草质量、牲畜生长需要和采食量及放牧方式。本文对这些要素进行了归纳分析,目的在于推进发展草地放牧饲养理论并推导草地生产和保护性利用的关键技术。本文介绍了草地生产率研究方法、适宜载畜率确定标准、划区轮牧区块数计算方法及间歇休牧期和放牧期确定方法。草地放牧饲养理论:基于土壤和气候,改善草地生产和饲草质量,制定适宜载畜率,确定合理放牧方式,满足放牧牲畜最佳生长需要,并维持草地健康,实现“双赢”或“三赢”。草地保护性利用关键技术:放牧场或割草场施肥,调整适宜的载畜率,延迟放牧及间歇休牧,确切的划区轮牧体系,放牧场和割草场等量配置,二时段饲养模式。

青海湖高寒草原植被群落结构和水源涵养功能对禁牧封育的响应

【目的】探讨禁牧封育对青海湖植被群落结构和水源涵养功能的影响,对准确评估禁牧封育在青海湖退化草地恢复过程中的作用具有重要意义。【方法】对青海湖北岸高寒草原设置自由放牧及不同封育年限样地,分析封育措施对植物物种数、生物量、功能群、土壤容重、持水量及孔隙度等指标的影响。【结果】(1)随封育年限延长,青海湖北岸高寒草原物种数呈降低趋势,植被盖度、地上地下生物量均呈先增加后降低趋势,禾本科植物在群落中的重要值占比逐渐增加。(2)禁牧封育对青海湖北岸高寒草原土壤水分特征的影响主要集中在0—20 cm。随禁牧封育年限延长,0—20 cm土壤容重逐步降低,0—10 cm土壤饱和持水量、毛管持水量、田间持水量及总孔隙度均呈先增加后稳定趋势。(3)土壤容重是影响青海湖北岸高寒草原植被群落结构的最主要土壤水分特征因子。【结论】从植被群落结构的角度考虑,青海湖高寒草原禁牧封育年限不应超过7年,超过7年应进行适度干扰。

草地培育的内涵和方法

草地培育在草业科学理论指导下,通过一系列草地管理措施,解决草-畜供需季节性不平衡这一根本性矛盾,提高和完善草业系统的结构与功能。根据草地培育的作用目标或其尺度与属性、实施主体有5种划分方法。主要包括封育、休牧、划破、补播、施肥、灌溉、火烧、放牧、人工增雨、研学旅游、智慧管理、政策法规等,这些方法通过改变草业系统或其组分而融入草畜反馈机制。草地培育遵循产业化、慎重改造、综合性和尺度对应等原则,集成技术之间协同或叠加,效果达到超饱和或盈饱和,关键是确定生态系统对培育措施的适应期、响应期和饱和期3组阈值。草地培育建立以放牧为基础的边牧边育的模式,重视“有害”生物作为生态系统不可替代的组分及其资源属性,建设以草地健康水平为基础的标准化的草地培育流程,推动智能化、机械化、规模化作业,提高培育效率和效益。

甘露醇对放牧绵羊瘤胃、粪便菌群结构以及血清抗氧化和免疫指标的影响

【目的】探讨甘露醇对放牧绵羊瘤胃、粪便微生物菌群及血清抗氧化、免疫指标的影响。【方法】选择7~8月龄、初始体重相近(27.10 kg±3.55 kg)的健康绵羊10只,采用单因素完全随机试验设计分为两组,每组5只。对照组绵羊补饲不添加甘露醇的玉米面100 g/d,试验组补饲添加1 g甘露醇的玉米面100 g/d。在自然放牧条件下饲喂35 d,其中预试期5 d,正试期30 d。在正试期开始和结束日放牧前称体重,计算平均日增重(ADG);在试验结束日放牧前分别采集瘤胃液、粪便及颈静脉血液,采用16S rRNA测序方法分析瘤胃及粪便微生物区系;采用相关试剂盒测定血清抗氧化和免疫指标。【结果】与对照组相比,(1)试验组绵羊ADG、瘤胃液pH和氨态氮(NH_(3)-N)含量均无显著差异(P>0.05);瘤胃液的总短链脂肪酸(SCFAs)、乙酸和丙酸浓度均显著提高(P<0.05)。(2)试验组绵羊瘤胃及粪便微生物OTU数目、Alpha多样性指数均无显著差异(P>0.05);瘤胃及粪便微生物基于abund_jaccard近似距离的PCoA均显著分离(P<0.05)。(3)在门水平上,试验组绵羊瘤胃微生物无显著差异(P>0.05),粪便中厚壁菌门相对丰度显著降低(P<0.05),拟杆菌门相对丰度显著提高(P<0.05);在属水平上,试验组绵羊瘤胃中瘤胃球菌科NK4A214相对丰度显著高于对照组(P<0.05),粪便中未分类的毛螺菌科相对丰度显著降低(P<0.05)。(4)试验组绵羊血清免疫相关指标均无显著差异(P>0.05),血清谷胱甘肽(GSH)和丙二醛(MDA)含量显著降低(P<0.05)。【结论】在放牧条件下补饲甘露醇可提高绵羊瘤胃液乙酸、丙酸和总SCFAs浓度和瘤胃中瘤胃球菌科NK4A214相对丰度;使粪便中厚壁菌门和未分类的毛螺菌科相对丰度降低,拟杆菌门相对丰度提高;提高机体抗氧化能力。

转入草场对牧户草场放牧强度的影响--基于自有草场和转入草场视角

【目的】探析牧户对自有草场和转入草场利用强度的差异问题,从而正确认识草场流转真实效应,推动草场流转走向规范化和促进草原生态环境改善。【方法】基于对内蒙古西乌珠穆沁旗6个苏木(镇)的实地调研数据,采用倾向得分匹配法(PSM),分析草场地块使用权属性对牧户放牧强度的影响,并在此基础上运用普通最小二乘法(OLS)进一步分析不同契约安排对牧户在转入草场放牧强度可能发挥的作用。【结果】牧户在自有草场和转入草场上的放牧强度有所差异。转入草场后,牧户会降低自有草场的放牧强度,倾向于在转入草场上放养更多的牲畜;不同契约安排对转入草场放牧强度的影响存在区别。签订书面契约和流转来源于亲戚熟人可在一定程度上约束牧户的放牧强度,而约定流转年限对牧户放牧强度未产生显著的影响。【结论】在后续草场流转的过程中,要重点关注转入草场使用程度监管、增强流转合同的约束力及对新型畜牧业经营主体的支持力度。

超声波干涉及可视化实验装置研制

为了丰富大学物理声学实验内容,研制了一种多功能超声波干涉实验装置。基于空气介质设计了双振子干涉声速测量实验和半波损失验证实验。分别采用干涉声场测量法和干涉条纹移动法进行声速测量实验,并利用示波器实现了干涉声场声压分布的可视化。分别以有机玻璃、橡胶和玻璃为反射面材料,利用干涉法验证掠入射条件下的半波损失现象,并估算出掠入射角的范围。该实验装置实验现象明显、可操作性强,获评北京市第十六届大学生物理实验竞赛一等奖。

不同牧压对天山北坡中段山地草甸植物群落特征及植物生活型的影响

【目的】研究天山北坡中段山地草甸植物群落特征在不同牧压条件下的变化,为建立合理放牧利用制度提供理论依据。【方法】通过对庙尔沟乡索尔巴斯陶夏、冬牧场的实际放牧强度和草场植被状况进行调查,选择重度(HG)、中度(MG)、轻度(LG)且具代表性地段的放牧场,设置3个不同牧压监测点,每个监测点设置3个重复。【结果】在不同牧压条件下,植物群落优势种略有差异,群落物种数随着放牧强度的增大而减少。随着牧压增大,禾本科、豆科等优良牧草的重要值下降,而杂类草及醉马草的重要值增大;不同牧压对植被生物量的影响最大,其次是植被的盖度和高度,对频度的影响较小,呈现出植被平均高度、总盖度和生物量随放牧强度增大而降低的趋势;不同放牧时期对山地草甸植被优势种和植物生活型有明显影响,在夏季放牧场中植株矮小、重要值很低的金露梅在冬季放牧场中却株型高大,重要值也极高。【结论】在不同牧压条件下,群落物种组成不同,HG、MG、LG物种数分别为26、22和33种,物种间数目相差明显。重度放牧降低了植物群落的高度、盖度和地上生物量,并增大了杂类草和醉马草的优势。随着放牧强度增大,植物的生活型和重要值发生了改变,这也是植物生长过程中适应环境变化的一种策略。

不同放牧强度对短花针茅荒漠草原生物多样性的影响

生物多样性对维持生态系统功能与服务至关重要,结合物种、谱系及功能多样性理解群落构建十分必要。本研究以内蒙古短花针茅(Stipa breviflora)荒漠草原植物群落为对象,研究了对照、轻度、中度及重度放牧下不同维度生物多样性对不同载畜率的响应。研究结果表明:各放牧处理均显著降低物种丰富度、Simpson、Shannon-Wiener及Pielou指数。此外,中度和重度放牧处理均降低了谱系多样性。各放牧处理均显著降低了群落功能丰富度(FRic)、功能分异度(FDiv)、功能分散指数(FDis)及Rao二次熵指数(RaoQ);中度和重度放牧处理显著降低了群落功能均匀度(FEve)。总体而言,随放牧强度的增大,群落功能多样性呈现出逐渐降低的趋势。此外,物种、谱系及功能多样性之间存在显著或极显著的相关性。总之,对不同维度生物多样性的分析有利于理解植物群落构建机制,为草地合理利用及可持续性提供一定的理论基础。

放牧策略对土壤与植被的影响及土壤湿度预测研究

文章旨在探索锡林郭勒草原的可持续放牧策略,以防止草原干旱和荒漠化。从机理分析的角度研究不同放牧政策对锡林郭勒草原土壤物理性质、植被生物量的影响,通过建立数学模型优化放牧问题,以期找到在锡林郭勒草原可持续发展情况下草场内放牧羊数量的最大阈值。此外,开发了一个基于双向长短期记忆网络的预测模型,用于准确预测不同深度土壤的湿度,以支持草原管理决策。模型在测试集上的表现与实际土壤湿度趋势一致,其中200 cm深度的土壤湿度RMSE仅为0.2,显示出其在锡林郭勒草原土壤湿度预测中的实用价值。

基于数字孪生技术的草场放牧系统

运用数字孪生技术,在对草场环境及牲畜状态进行感知的基础上建立草场放牧监测系统。该系统将虚拟仿真技术Unity3D应用于草场放牧场景的孪生三维模型,为后续监测呈现可视化效果;采用无线传输技术搭建采集网络,实现草场及牲畜信息交互的功能,并选用模糊综合评价方法对草场进行放牧强度划分。为了验证该系统的有效性,以内蒙古锡林郭勒盟锡林浩特市毛登牧场的真实场景为例进行综合试验。结果表明:与传统的放牧监测系统相比,该系统运用数字孪生技术实现了数据共享和物理草场与孪生草场信息的同步,有效解决了传统放牧监测中决策滞后的问题;通过孪生草场能对物理草场的放牧场景进行仿真模拟,不受客观条件限制,能有效预测各种放牧情况,实现草场环境及牲畜放牧状态精准监测,在实际放牧中能及时应对突发情况,提升草场放牧决策的自主性。