呼伦贝尔草地野生豆科牧草资源及其特点

对呼伦贝尔草地野生豆科牧草的属种组成、生长习性及饲用价值进行了研究.结果表明, 呼伦贝尔草地现有豆科植物17属64种.这些豆科牧草大多为多年生草本植物,适应典型草原和丘陵草甸草原生境,饲用价值较高,适口性良好,是植被组成中的重要组成成分,生态利用前景广阔,是本地区重要的饲草资源.     

西藏野生优良牧草资源及其开发利用

西藏草地面积辽阔,饲用植物资源丰富.饲用植物共有2 672种,分属于83个科、557个属.其中以莎草科、禾本科和杂类草等为主要种类.充分利用当地野生优良牧草资源,培育适应西藏不同生境的当家牧草品种,对改良和建设草地、改善草地生态环境、遏制藏北草地退化具有重要意义.     

黄河三角洲地区野生饲用植物资源构成分析

为了给黄河三角洲地区野生饲用植物资源的开发和利用提供理论依据,对该区域的野生饲用植物资源进行了调查和研究,初步统计黄河三角洲地区野生饲用植物有40科118属172种.并介绍了该区域饲用植物的科属种组成、区系分布、地理分布及饲用价值等,并对其利用提出了一些建议.     

大兴安岭森林草原过渡带典型植物群落动态变化特征

大兴安岭森林草原过渡带是大兴安岭森林与呼伦贝尔草原接壤的关键区域。由于过渡带本身的脆弱性,气候变化和过度放牧等人为因素的干扰导致区域内植物群落结构和功能发生剧烈变化。然而,气候变化和放牧双重作用对森林草原过渡带草地植物群落动态影响的研究还鲜有报道。以内蒙古陈巴尔虎旗森林草原过渡带为研究对象,分别于2008、2009、2010和2019年沿着草甸草原-森林草原过渡区域-林间草地-森林的梯度进行野外调查,对比分析11年间受气候变化和过度放牧的双重干扰下,该区域植物物种丰富度、Raunkiear生活型功能群、牧草饲用价值以及群落生物量随时间的变化动态。结果表明：从总体上看,与2008-2010年均值相比,2019年植物物种数量明显下降,其中禾本科牧草减少10余种;植物Raunkiear生活型功能群组成发生显著变化,其中一、二年生植物物种数增加4%,地面芽植物降低8%;牧草饲用价值中优等牧草所占比例下降5%,劣等牧草比例增加7%;总地上生物量显著下降35%。在过渡带各区段中,草甸草原群落结构和功能受气候和过度放牧影响更加明显。与2008-2010年均值相比,2019年草甸草原群落物种丰富度降低12%,优等牧草比例降低4%,劣等牧草比例增加7%,植物地上生物量更是显著降低62%。对区域气候和放牧因素分析可得,年降水量和年均温与过渡带地上生物量均显著相关,其中降水是导致过渡带整体上生产力下降的主要因素;而过度放牧是导致草甸草原群落生产力下降的主要因素。     

科尔沁草地植物种质资源的数量特征

以通辽地区科尔沁草地为研究对象,采用样地调查探析该地区草地植物种质资源数量特征。结果表明:通辽地区科尔沁草地的植物种类组成十分丰富和复杂,共有42科,163属,276种,其中优良牧草种类占35.15%;可将草地类型划分为5大类、7个亚类、17个草地组,其中以羊草(Leymus chinensis)为建群种的群落占主要优势,分布最为广泛;因此,本文深入研究了羊草群落的生物量与物种多样性、地理分布的关系,即羊草群落随着物种多样性的增加,群落地上生物量明显增加,呈正相关关系;同时,羊草群落的地上生物量也受到地理因子变化的影响,地上生物量随着经度升高而增加,随着纬度升高而降低。本研究对增加该地区优质牧草产量、改良退化草地、发展草原畜牧业提供了重要的科学数据,对于更好恢复和管理该地区重要的草地资源以及地区经济发展具有重要意义。     

青藏高原北部多年冻土退化过程中生态系统的变化特征

多年冻土的发育是青藏高原冻土区生态系统稳定的基础,而多年冻土退化效应是目前青藏高原研究的热点。研究了青藏高原北部多年冻土退化过程中生态系统的变化特征。结果表明:在多年冻土退化的过程中,土壤温度逐渐升高,土壤含水量下降,有机质含量降低,植被类型表现为从沼泽化草甸演替为典型草甸,草原化草甸,最终成为沙化草地,群落植物组成从湿生或中湿生逐渐向中生、中旱生乃至旱生转变,草层高度变矮,植被盖度下降,α和β多样性均表现为先增加后减小,在草原化草甸阶段达到最大;草地植物生物量和载畜能力总体表现为降低趋势,但在典型草甸和草原化草甸之间差异不显著。植被经济类群的变化趋势表现为优良的莎草科和禾本科牧草比例下降,而毒杂草比例显著增加,牧草品质下降,饲用价值降低。     

海南野生禾本科牧草种质资源调查、收集与鉴定

2005年11月-2006年3月对海南省19个市县分布的禾本科牧草资源进行了调查、收集与整理,本次调查共收集到禾本科植物74个属、159种,分别占海南禾本科种质资源属数的73.27%和种数的77.56%,其中《海南植物志》未记载的有4个属、21个种。本文对调查和收集的资源种类、分布情况、营养价值进行了分析,并对牧草资源的保护进行了讨论。     

禾本科牧草分子生物学及生物技术研究进展

牧草的研究和开发在我国西部生态建设和草地畜牧业发展等方面具有十分重要的意义。禾本科牧草的分子生物学及生物技术研究虽然起步较晚,但在近年取得了令人可喜的进展。以黑麦草属、鸭茅属、羊茅属、赖草属和披碱草属的几种“模式牧草”为重点,从分子标记研究、遗传图谱绘制、基因克隆以及遗传工程等方面对这些研究进展进行了综述。对Genbank中已登录的众多基因进行了信息汇总分析。重点评述了禾本科牧草繁殖方面的分子生物学研究进展。对分子标记、基因工程和比较基因组学应用于禾本科牧草的研究给予了前景展望。     

呼伦贝尔草原药用盐生植物资源及利用

根据调查结果,统计出呼伦贝尔草地野生药用盐生植物共52种,隶属于19科44属,其中药用价值高、资源丰富,具备开发潜力的约10种,建议对这些资源进行合理的开发利用。     

松嫩平原农牧交错区牧草资源特点及畜牧业发展

以长岭县为例,对松嫩平原农牧交错区的牧草资源分布格局、牧草资源承载力和利用现状等进行分析。结果表明：放牧系统（草地-林地-农田组成）提供的牧草资源已不能满足当地畜牧业对牧草资源的需求。草地承载力仅占当前实际载畜量的16．6％,草地-林地-农田放牧系统承载力为实际载畜量的47．3％;作物秸秆转化为牧草资源的潜力巨大。经估算,作物秸秆占总牧草资源的78．3％,是当前畜牧业对牧草资源需求量的2．4倍。当前,农牧交错区牧草资源的粗蛋白含量普遍偏低,不能完全满足动物生长的需要,制约了当地畜牧业发展。根据当地畜牧业现状、牧草资源潜力,提出：应合理利用草地-林地-农田3个放牧子系统所提供的牧草资源,充分利用其它牧草资源,如作物秸秆;有汁划地建立高产优质、富含粗蛋白的人工牧草基地,增加牧草粗蛋白含量,提高牲畜对牧草资源的利用效率（吸收率）;充分有效地利用各种牧草资源,减轻草地放牧压力,实现畜牧业可持续发展与生态保护的协调统一。     

Spatial and temporal feeding segregation of two Icelandic goose species during the spring pre-nesting period

The pre-nesting feeding behaviour of greylag Anser anser and pink-footed geese A brachyrhynchus was studied on agricultural land at low altitude in southern Iceland from 10 April to 8 May 1990 Greylag geese were already present on 12 April increased to 4580 birds by 24 April, but declined to 1300 by 3 May Pink-footed geese arrived around 20 April and numbers continued to increase to a peak count of 11340 on 3 May Over 60% of greylag geese initially used stubble fields on the coast where this habitat was most frequent, but increasingly resorted to grassland and wetland habitats during late April Later-arriving pink-feet predominantly used managed grassland, away from coastal areas At inland grassland sites, greylag numbers peaked on 20 April, pink-feet m early May The early exploitation by greylags was associated with grass growth initiated under protective snow-patches Greylags spent 90 times more time feeding within 1 m of snow patches with enhanced grass growth than expected by chance and their feeding rates near snow patches were faster and their step rates slower than further away By early May, grass growth was uniform and, although snow-patches persisted, no difference in forage quality, goose feeding rates or step rates could be detected It is concluded that, in spring 1990 at least, habitat segregation during spring migration in southern Iceland minimised competition between these two closely related goose species within the same geographical area In areas where both species exploit the same habitat, a two week difference m timing of breeding (and hence phenology of migration) further assures minimal overlap in feeding exploitation     

黄土高原半干旱区退化草地恢复与利用过程研究

草地退化表现为土壤和植被遭到彻底破坏,草地演替过程受到强烈抑制.实验采用长期(30年)封禁措施,定位监测退化草地从次生半裸地演变为近似原生植被(进展演替)的变化过程.结果表明,随着封禁时间的变化,退化草地恢复演替经历了4个阶段,群落盖度、植株密度、物种丰富度和多样性指数、地上生物量和地下生物量在草地群落恢复过程中逐渐增加,其特征变化出现的峰值均在封禁第20年(地下生物量峰值在第15年),其中地上生物量最高达520.5 g/m2;直到封禁的第20~25年,以本氏针茅为建群种的草原群落衰败退化现象明显,而大针茅种群密度剧增;在封禁的第26年以上以大针茅为优势的群落生长较为稳定,从目前群落演替进程看,大针茅有替代本氏针茅的趋势.另外,在草原沟道两侧以斑块状聚集分布有中旱生灌木,群落的演替进入了一个新的阶段.随着封禁时间的延续,退化草地从自然封禁恢复的0~26年,通过侵入-竞争-扩散-定居的几个演替阶段,目前形成以大针茅为建群种相对稳定的"亚顶级".虽然草地生物量有一定下降,但草地质量提高,物种多样性丰富,促进草地的进展演替.草地植物群落主要由禾本科、豆科和菊科组成;多年生植物、C3和旱生物种可以作为草地演替过程和植被恢复的指示物种.长期封育对草地物种更新和生态系统稳定性有负面影响,因此,合理的封育时间是草地生态恢复中非常重要的一个因素.本研究提出,在黄土区退化草地封育10~15年后可以开始进行合理的利用,例如通过两年一次刈割和轻度放牧(2只羊/hm2).本研究可为干旱区、半干旱区相似的退化草地恢复提供理论依据.     

高寒小嵩草草甸牦牛优化放牧强度的研究

高寒小嵩草草甸牦牛放牧强度试验表明:(1)不同放牧强度下各植物类群的地上生物量和总的地上生物量之间差异极显著,莎草科植物地上生物量的百分比组成之间差异极显著,禾本科和杂类草地上生物量的百分比组成之间差异显著,而且禾本科和莎草科(除对照外)植物的地上生物量及其百分比组成随放牧强度的增加而减小,杂类草的变化与之相反;(2)优良牧草比例和草地质量指数与放牧强度之间均呈负相关,而优良牧草比例的年度变化和牦牛个体增重的年度变化之间呈正相关;(3)群落的相似性系数随放牧强度的增加而减小.通过建立植被变化度量指标,认为优良牧草比例的年度变化是评价高寒小嵩草草甸放牧价值的直接度量指标,而相似性系数的变化和草地质量指数的变化与牦牛生产力没有明显的联系,不能反映草场植被放牧价值的变化,只能指示植物群落整体的相对变化程度;牦牛的放牧强度约为1.86头/hm2是小嵩草高寒草甸暖季草场可持续生产而不退化的最大放牧强度.     

Forage nutritional characteristics and yield dynamics in a grazed semiarid steppe ecosystem of Inner Mongolia,China

In the steppe of Inner Mongolia, forage is the only source of feed for sheep. The forage intake of sheep can be characterized in both quantity and quality terms, which are determined by environmental and anthropogenic factors and grazing has a strong effect on steppe productivity and the grassland ecosystem. Evaluation of forage quality and quantity is therefore of critical importance. The effects of grazing intensity, interannual variability effects, and species composition on aboveground net primary productivity (ANPP) and forage nutritional characteristics were investigated in a controlled grazing experiment along a gradient of 7 grazing intensities (from non-grazed to very heavily grazed) over six years (2005–2010) on typical steppe in Inner Mongolia. Forage nutritional characteristics were defined by the nutritional value (concentrations of crude protein (CP), cellulase digestible organic matter (CDOM), metabolizable energy (ME) and neutral detergent fibre (NDF)) and the nutritional yield. The forage nutritional yield is a function of ANPP and the forage nutritional value. Forage nutritional value increased but ANPP and nutritional yields decreased with increasing grazing intensity. The inter-annual variation of ANPP, forage nutritional value and yield were weakly linked to the inter-annual variability of precipitation. However, ANPP and nutritional value also varied during the growing season, depending on the seasonal distribution of precipitation and temperature, which influence forage digestibility (CDOM) and metabolizable energy (ME), with higher CDOM and ME under high seasonal precipitation and low seasonal mean temperature. Forage nutritional value and yield, as well as ANPP, were predominantly determined by the dominant species rather than by species diversity. The results suggest that forage nutritional yield in the Inner Mongolian steppe is predominantly determined by the ANPP and only to a minor extent by forage nutritional value, and is predominantly determined by the dominant species and only to a minor extent by species diversity. Therefore, herbage productivity seems to be the most limiting factor in managing this steppe ecosystem as a feeding resource for livestock and to be the best ecological and environmental indicator for grassland management practices.     

Emerging technologies advancing forage and turf grass genomics

Grassland is of major importance for agricultural production and provides valuable ecosystem services. Its impact is likely to rise in changing socio-economic and climatic environments. High yielding forage grass species are major components of sustainable grassland production. Understanding the genome structure and function of grassland species provides opportunities to accelerate crop improvement and thus to mitigate the future challenges of increased feed and food demand, scarcity of natural resources such as water and nutrients, and high product qualities.     

Modelling ungulate dependence on higher quality forage under large trees in African savannahs

In African savannahs, large trees improve grass quality, particularly in dry and nutrient poor areas. Enhanced below-canopy grass nutrients, such as nitrogen and phosphorus contents should therefore attract and benefit grazers. To predict whether ungulates really need these forage quality islands we focused on four grazer species, i.e., zebra, buffalo, wildebeest, and warthog, differing in body size and digestive system. We confronted literature estimations of their feeding requirements with forage availability and quality, observed in three South African savannah systems, through linear modelling. The model predicted the proportion of below-canopy grass that grazers should include in their diet to meet their nutritional requirements.During the wet season, the model predicted that all animals could satisfy their daily nutrient requirements when feeding on a combination of below- and outside-canopy grasses. However, wildebeest, having relatively high nutrient demands, could meet their nutrient requirements only by feeding almost exclusively below canopies.During the dry season, all animals could gain almost twice as much digestible protein when feeding on below – compared to outside-canopy forage. Nonetheless, only warthogs could satisfy their nutrient requirements – when feeding almost exclusively on below-canopy grasses. The other ungulate species could not meet their phosphorus demands by feeding at either site without exceeding their maximum fibre intake, indicating the unfavourable conditions during the dry season.We conclude that grazing ungulates, particularly warthog, zebra, and buffalo, actually depend on the available below-canopy grass resources. Our model therefore helps to quantify the importance of higher quality forage patches beneath savannah trees. The composition of grazer communities depending on below-canopy grasses can be anticipated if grazer food requirements and the abundance of large trees in savannahs are known. The model suggests that the conservation of large single-standing trees in savannahs is crucial for maintenance of locally grazing herbivores.     

呼伦贝尔草原不同草地利用方式下生物多样性与生物量的关系

生物多样性与生产力的关系是当前生态学中研究的重点之一,以呼伦贝尔草原为研究对象,通过连续两个生长季的野外监测,从草地植物功能型的角度探讨了在不同利用方式下草地物种丰富度与地上生物量的关系,结果表明：（1）不同草地利用方式显著影响草地生物多样性和生产力,在3种不同利用方式中,生物多样性总体的趋势是割草〉围封〉放牧,其中Shannon-Wiener指数、Simpson指数和物种丰富度均差异显著;割草草地地上生物量最高,围封草地次之,放牧草地最少。（2）将草地植物按照植物功能型分类,放牧草地1、2年生植物占优势,随着物种丰富度的增加,1、2年生植物生物量没有明显的变化趋势;割草草地以禾本科植物和非禾本科植物为主,随着物种丰富度的增加,禾本科植物生物量呈下降趋势,而非禾本科植物变化不明显;围封草地中禾本科植物占优势,其他功能型植物分布较均匀,多度、频度和生物量等差异不显著。（3）3种草地利用方式中只有围封草地物种丰富度和地上生物量存在显著的正相关,即随着物种丰富度的增加,生物量也随之升高。其他两种利用方式下,物种丰富度对地上生物量没有显著影响。     

Hierarchical resource selection by impala in a savanna environment

The factors that affect resource selection by a foraging herbivore can vary according to the resources or conditions associated with particular levels of organization in the environment, and to the scales over which the herbivore perceives and responds to those resources and conditions. To investigate the role of forage in this hierarchical process, we studied resource selection by a mixed‐feeding large herbivore, the impala (Aepyceros melampus). We focussed on three spatial scales: plant species, feeding station and feeding patch. In paired sites where impala were and were not observed, we identified the plant species from which animals fed, the attributes of the plants, and the characteristics of the broader site. Across all three scales, plant species available as forage was central in determining resource selection by impala. At the species level, that effect was modified by the nutritional quality (greenness) and whether it was during a period of forage abundance or scarcity (season). At the feeding‐station level, overall greenness and biomass of the station were important, but their effects were modified by the season. At the feeding‐patch level, broader‐scale factors such as the type of vegetation cover had an important influence on resource selection. The grass Panicum maximum was a preferred forage species and a key resource determining the locations of feeding impala. Our findings support the idea that selection by a foraging herbivore at fine scales (i.e. diet selection) can have consequences for broader‐scale selection that result in observed patterns of habitat use and animal distribution.     

内蒙古锡林郭勒盟草原产草量动态遥感估算

草原产草量的监测是草地资源空间动态研究的重要衡量指标,是草地资源合理利用和载畜平衡监测的重要依据.基于371个样地调查数据和2005～2009年的MODIS-NDVI遥感数据,建立地面样方的产草量与遥感数据的关系模型,模拟分析了内蒙古锡林郭勒盟草原产草量的时空分布.结果表明：（1）建立的各模型方程均有较好的相关关系,其中幂函数的相关关系最优,通过预留样方数据的验证,模型精度为78%,幂函数模型作为遥感估测应用可行;（2）锡林郭勒盟草原的产草量5年平均为3455万吨,折合干草总量为1112万吨,平均单产为567.23kg/hm2,草原产草量的空间分布呈东高西低的格局;（3）2005～2009年,锡林郭勒盟草原产草量有明显的波动,干草变化范围为800～1400万吨,变异系数为20.42%;（4）不同草地类型的产草量及其年际间变化存在较大的差异,荒漠类草原产草量低,年际间变化较大;草甸类草原产草量高,年际间变化相对较小.草原产草量的时空变化还与降水量、气温等主要气候因素关系密切,特别是受降水量的时空变化影响显著.研究结果可以为中国草地资源的保护及合理利用提供参考依据.