生计方式对农户生活能源消费模式的影响——以甘南高原为例

生计方式变迁对农户的生活能源消费模式产生深远影响,从而给农村能源与环境问题带来新的挑战。以地处青藏高原东缘的甘南高原为研究区,基于农户调查资料,采用STIRPAT模型与二元logistic模型分析了生计方式对农户的生活能源消费量及生活能源消费模式选择的影响。结果发现:(1)随着非农化水平的提高,甘南高原农户的生活能源消费量显著下降,但它引起的生活能源消费量下降速度低于其自身的变化速度;此外,家庭规模扩大、收入提高将使农户的生活能源消费量增加;(2)生计方式对农户能源消费模式选择的影响远高于其他因素,随着非农化水平的提高,农户选择以商品性能源为主消费模式的概率将增大,收入增加、受教育程度提高及商品性能源的可得性改善亦会如此,但生物质能源的可得性增强会降低农户选择以商品性能源为主消费模式的概率。最后,提出了优化农户生活能源消费模式的建议。     

Diet composition influences annual breeding success of Montagu's Harriers Circus pygargus feeding on diverse prey

Capsule Three similarly sized passerine species with various breeding strategies behaved differently in the presence of models of mammalian and avian predators.

Aims We tested whether solitary breeders behave in the presence of a predator in order to avoid disclosing their nest site in: hole-nesting Pied Flycatcher Ficedula hypoleuca, shrub-nesting Blackcap Sylvia atricapilla and ground-nesting Meadow Pipit Anthus pratensis.

Methods The behaviour of parents in response to two types of predator model (visually oriented Corvid birds and olfactory oriented Mustelid mammals) placed sequentially at 40, 5 and 1 m distance from the nest was recorded from a shelter.

Results The hypothesis was supported in open-nesting species (Meadow Pipit and Blackcap), as parents did not approach the nest in the presence of a predator. In the hole-nesting Pied Flycatcher the parents disclosed the nest site in most cases (by entering the nest). The intensity of alarm calling increased with decreasing distance of a predator from the nest in all species except Meadow Pipit in the presence of Raven Corvus corax models. The intensity of attacking changed only in Meadow Pipit with decreasing distance of Stoat Mustela erminea from the nest.

Conclusion The results showed that anti-predator behaviour was species-specific, depending on type of predator, habitat and nest inaccessibility.     

Grassland management for meadow birds in the Netherlands is unfavourable to pollinators

Agricultural intensification and loss of semi-natural grassland have contributed to biodiversity decline, including pollinator species, in pastures around the world. To reverse the decline, agri-environmental schemes have been implemented, varying widely in effectiveness. In addition, many countries, including the Netherlands, have established nature reserves in which semi-natural grasslands are restored and are often managed for specific groups of species, e.g. meadow birds or plants. The effects of such measures on insect biodiversity are not well known but recent reports on the dramatic decline of insect biomass in nature reserves have put even more attention to the impact of land use and management on biodiversity. This study compares pollinator abundance and species richness in three common semi-natural grassland management types in the Netherlands: (1) hay meadows, (2) herb-rich grasslands and (3) meadow bird grasslands. Pollinator abundance and species richness were assessed in eleven study areas, each with all three management types present. Standardized transects, insect sampling within a standard 20 min time frame and plot-based flower surveys were used in spring and summer to assess the relationships between management regime, floral abundance and diversity and pollinator communities. The results show that meadow bird grasslands have lower pollinator abundance and diversity and a less unique pollinator assemblage than both other types. Moreover, flower abundance has a positive effect on pollinator abundance and flower diversity has a positive effect on pollinator species richness. These results indicate that meadow-bird grasslands are a comparatively unfavourable habitat for bees, hoverflies and butterflies, which may be explained by a lack of flowers as well as unsuitable mowing practices. Measures benefitting both insectivorous birds and flower-visiting insects, such as rotational mowing, could remediate this imbalance.     

甘南牧区草畜平衡优化方案与管理决策

利用Matlab 7.9软件的多目标规划方法,以甘南牧区2008年及以前的草地畜牧业动态监测资料和社会经济发展调查统计数据为基础,以维持草畜平衡、优化畜群结构和保护草地生态环境为总目标,综合考虑牧区畜群结构优化、牧业生产目标、草畜动态平衡、区域社会经济收益状况和生态环境保护5个方面的约束条件,研究了规划期(2009-2011年)甘南牧区草地畜牧业发展的优化方案及管理对策,对比分析了减畜和增畜2种优化方案在畜群结构、牲畜总增率、净增率、商品率、出栏率、农牧民纯收益等方面的数量变化特征,提出甘南牧区草畜平衡优化方案及管理决策。研究结果表明,减畜优化方案是实现上述目标的根本途径。具体措施包括:1)适度调整牲畜数量,改良品种,优化畜群结构;2)调整农作物播种面积及结构,增加人工草地种植面积,提高补饲水平;3)稳定天然林草地面积,维护牧区生态环境; 4)增强畜牧业生产效益,提高出栏率;5)严格控制人口数量,加强国家政策调控机制。     

高山植物圆穗蓼的繁殖资源分配

于海北高寒草甸生态系统定位站附近的一个西向山坡上,以高寒灌丛草甸中海拔不同的4个地点的圆穗蓼为研究对象,分析圆穗蓼的繁殖特征在海拔梯度上的变化规律,以探讨高山植物在极端环境下的资源分配策略。结果发现:(1)随海拔升高,圆穗蓼的植株高度先增大后变小,营养器官生物量和繁殖器官生物量均呈现增加的趋势,但三者与海拔梯度的相关性不显著,而且繁殖分配在4个不同海拔取样地点间差异不显著;(2)个体越大,圆穗蓼分配到繁殖器官的绝对资源比例也显著增加,但在海拔较低的3个取样地点内,繁殖分配随海拔升高呈增加的趋势,这可能与高寒灌丛草甸土壤的潜在肥力较高而导致圆穗蓼不存在资源限制有关;(3)圆穗蓼在4个取样地点均存在繁殖阈值,繁殖阈值与海拔的相关性不显著,但仍然表现出随海拔升高而略有降低的趋势,表明海拔较高居群的植株达到开花繁殖需要的营养积累较小。研究表明,由于海北站的土壤肥力较高,4个取样地点的圆穗蓼不存在个体大小依赖性的繁殖分配和随海拔升高而增加的繁殖分配;而高海拔取样地点较低的繁殖阈值表明高山植物的有性繁殖比营养生长具有更为重要的意义,强调了有性繁殖对高山植物的重要性。     

三种人工栽培大黄的泻下作用比较研究

目的：对比研究三种人工栽培大黄的泻下作用。方法：本研究采用KM小鼠96只,雌雄各半,按性别体重分层随机分为8组（n=12）。采用复方地芬诺酯复制便秘动物模型,通过药物干预,对比观察甘南栽培唐古特大黄与西宁栽培唐古特大黄、礼县栽培掌叶大黄的泻下作用。结果：2．0～6．0g／ks剂量范围内的甘南栽培唐古特大黄、西宁栽培唐古特大黄及礼县栽培掌叶大黄可明显缩短便秘小鼠的排便时间,增加排便次数,提高大肠含水量,抑制结肠NO＋K＋-ATP酶的活性;甘南栽培唐古特大黄的上述作用明显强于礼县栽培掌叶大黄,而甘南栽培唐古特大黄与西宁栽培唐古特大黄的上述作用未见明显差异。结论：甘南栽培唐古特大黄具有明显的泻下作用,甘南栽培唐古特大黄与西宁栽培唐古特大黄的泻下作用无明显差异;抑制结肠NO＋K＋-ATP酶的活性是甘南栽培唐古特大黄泻下机制之一。     

Ground vegetation in the Mongolian taiga forest‐steppe ecotone does not offer evidence for the human origin of grasslands

Question: Is the vegetation of meadow and mountain steppes distinct from the ground vegetation of light taiga forests in the transitional zone between these biomes? Location: Western Khentey Mountains, northern Mongolia. Methods: Vegetation was recorded from 100‐m² plots from all dominant types of light taiga forest and dry grassland. Distinctness of ground vegetation was studied with Detrended Correspondence Analysis (DCA). Results: Ground vegetation in the light taiga was significantly different from the herbal vegetation of meadow and mountain steppes. Clear separation was only absent for the Car ex amgunensis meadow steppes that occur in a narrow strip along the forest edge and are partly shaded by trees. Forest and steppe communities followed a moisture gradient according to the DCA ordination with light taiga forests at the moistest sites and steppe communities at the driest sites. Ulmus pumila open woodlands diverged from this pattern, because of their close spatial and phytosociological relationship to mountain steppes. Conclusions: The present results do not support the assumption that grasslands in Mongolia's transitional zone between forest and steppe would generally resemble the ground vegetation of light taiga forests. This contradicts a published hypothesis stating that the vegetation of meadow and mountain steppes would not clearly differ from ground vegetation of light taiga forests in the forest‐steppe transitional zone of Mongolia.     

田鼠种群波动的原因和时间

本文总结了橙腹田鼠（Microtus ochrogaster）和草原田鼠（M．permsylvanicus）25年的种群统计学研究结果和结论。探讨了田鼠种群波动周期性、诱发种群波动以及导致波动期间峰值变异的因素。并对种群存活值和繁殖活动的作用进行了分析和评价。根据两种田鼠种群波动周期性、波动峰值出现的时间以及特定年份峰值的高度等特征,证明两物种波动均具有不稳定性。两种田鼠存活值的变化是由特定年份是否发生波动以及波动峰值出现的时间决定。增加初始阶段的种群密度及时间长度是造成两种动物种群波动峰值不同的主要原因。橙腹田鼠种群停止增长的原因是存活值降低,而草原田鼠则是繁殖活动减少。据推测,与种群波动初始密度相关的种群死亡率的差异是由捕食者的净效应（Net effect）决定的,调控两种群密度的因素均为非密度的其它生态学因子。由于特定年份田鼠种群捕食压力的不确定性,导致了橙腹田鼠和草原田鼠种群波动的不稳定性。     

高寒生态脆弱区农户对气候变化的适应需求——以甘南高原为例

气候变化对以自然资源为生计基础的农业人口的影响尤为显著。明确农户对气候变化的适应需求,对于制定有效的气候变化适应政策、增强农户的气候变化适应能力非常重要。基于500份农户调查问卷,分析了甘南高原不同区域和不同生计方式农户对气候变化的适应需求,并利用二元logistic回归模型分析了影响农户适应需求的关键因素。结果表明:(1)在适应气候变化过程中,甘南高原农户对基础设施的需求最强烈,对信息和生产技术的需求次之;(2)不同区域农户对气候变化的适应需求存在差异。其中,纯牧区农户和农区农户对基础设施的需求均最强烈,半农半牧区农户对信息的需求最强烈;(3)不同生计方式农户对气候变化的适应需求也存在差异。其中,纯农户对信贷保险的需求最强烈,一兼户和二兼户均对基础设施的需求最强烈;(4)自然资本和物质资本是影响农户对生产技术需求的关键因素,自然资本和人力资本是影响农户对信息需求的关键因素,人力资本和金融资本是影响农户对基础设施需求的关键因素,自然资本、人力资本、金融资本、物质资本和社会资本均是影响农户对信贷保险需求的关键因素。提出了提升农户适应气候变化能力的政策建议。     

内蒙古草甸草原CH4和N2O排放通量的时间变异

 1998年6月1日、7月2日、8月3日和9月1日用静态箱-气相色谱法对内蒙古锡林河流域草甸草原CH4和N2O排放通量的昼夜观测表明,天然草原是N2O的源、CH4的汇,其排放和吸收具有明显的昼夜变化规律。4次昼夜观测的结果还表明,草甸草原排放N2O和吸收CH4的能力具有强烈的季节变化规律