封育措施对呼伦贝尔草甸草原区草地生产力的影响

目的 研究围封条件下植物群落中物种变化的分布特征,有助于解释退化草地在不同围封阶段演替规律。方法 文章以温性草甸草原为研究对象,采用野外定位随机采样方法,调查群落生物量、植物物种种类、密度、盖度及高度,探讨时间尺度封育状态下的温性草甸草原植物群落特征、物种多样性的变化。结果 （1）封育措施显著增加了群落盖度,比围栏外的自由放牧样地提高了13.79%~114.75%,且随着封育年限的增加群落盖度表现出先增加后降低;而封育措施对群落密度没有显著性影响。（2）封育显著增加了植被地上生物量、地下生物量以及禾草生物量,其中地上生物量较围栏外的自由放牧样地提高了66%~887.3%,禾草生物量和地上生物量均随着封育年限的增加表现出先增加—降低—增加—降低的波动变化,地下生物量在监测年份下表现为先增加后降低的变化;封育措施可以提升植物多样性,随着封育年限的增加,多样性指数和丰富度指数呈现先增加后降低的变化趋势。结论 封育措施可以显著提高草地生产力,并且对物种多样性也有一定的促进作用,是应对退化温性草甸草原恢复的有效措施,但退化草地在长期围封后,应进行适度利用来维持较高的生产力。     

有机肥对草甸草原植物群落及物种多样性的影响

[目的]施肥措施是一项维持草原生态系统养分平衡的有效管理方式。文章通过田间试验研究了不同有机肥施用量对草地植物群落的影响,为退化草地的恢复和改良提供参考和理论依据。[方法] 2014—2021年立足于呼伦贝尔羊草（Leymus chinensis）草甸草原连续多年的施肥控制试验样地,设置了4个长期施肥处理：不施肥处理（Y0）、低水平有机肥处理（Y1）、中水平有机肥处理（Y2）和高水平有机肥处理（Y3）,研究植物物种重要值、功能群和群落物种多样性,并分析在不同施肥处理下的相关性关系和交互作用。[结果]（1）随着施肥水平的升高羊草重要值呈抛物线函数变化趋势,且中度施有机肥处理下最高;有机肥添加后的群落以及优势种羊草植物特征数值显著高于不施肥处理;植物群落多样性指数均随着施肥水平的升高逐渐减小。（2）施有机肥处理的群落高度、密度、盖度以及地上生物量的响应比显著高于不施肥处理;植物群落物种多样性指数响应比随着施肥水平的升高而降低的趋势比较明显。（3）群落功能群分类与不同施肥水平之间的交互作用显著,禾本科、豆科和毛茛科植物的重要值在不施肥处理与施肥处理之间差异显著;禾本科的重要值与多样性指数之间...     

呼伦贝尔草甸草原不同放牧强度下植被特征分析

该文利用草地的野外实测数据,计算了物种综合优势比、物种丰富度、物种多样性及其群落高度、盖度、密度、地上生物量等数量指标,对两种草甸草原样地三种放牧强度的群落结构和功能指标进行了研究。结果表明:从物种水平分析,羊草草甸草原样地(LM)和贝加尔针茅草甸草原样地(SM)的建群种的综合优势比随放牧强度加大而下降,而退化标志物种,如寸草苔、糙隐子草及冷蒿等呈上升趋势。从群落水平分析,LM样地比SM样地物种多样性维持能力弱,耐牧性弱。     

喀纳斯景区草地景观美学价值评价及影响因素分析

[目的]自然景区的美学价值大小直接决定着其旅游开发的成败,为了解喀纳斯景区草地景观美学价值。[方法]该文选用心理物理学派的美景度评价体系,对景区内4个区域草地景观的美景度进行了定量评价,并依据上述样地植物群落α多样性和功能群结构的分析,探讨了植物多样性对喀纳斯景区草地景观美景度的影响。[结果]研究表明:喀纳斯景区草地景观美学价值整体较高,α多样性指数居中的草地美景度得分较高,α多样性指数较高的草地美景度次之,α多样性指数较低的草地美景度最差;随着功能群中一、二年生植物重要值的上升,多年生杂类草的重要值下降,美景度呈降低的趋势;美景度与平均高度、平均盖度、生物量、Shannon-Wiener指数、Margalef丰富度指数、Simpson指数和多年生杂类草重要值呈显著正相关,而与一、二年生杂草重要值呈显著负相关。[结论]因此,草地植物多样性是草地景观美学价值的重要载体,旅游活动导致草地群落植物多样性发生改变,进而深刻影响了草地景观的美学价值。     

三江平原湿草地的研究

三江平原为我国天然湿草地集中分布区,现有草甸544.3万亩、沼泽化草甸1194.8万亩,轻沼泽724.8万亩,占三江地区总面积的15.06％。现存主要饲料植物年总蓄积量为419.3万吨。各类湿草地演替中心为小叶樟草甸,开发潜力很大,已初见成效。     

达日县高寒草甸土壤理化性质与物种多样性、地上生物量的关系

利用55个1m×1m的野外样方调查数据初步分析了达日县高寒草甸3种植被群落类型物种多样性与地上生物量及其同土壤理化性质的关系。结果表明:(1)土壤pH值和养分全量含量越低,其土壤有机质含量和速效养分含量越高。(2)在9个样地55个1m×1m的样方中共出现105种植物,物种丰富度最高为27种/m2,最低为4种/m2。(3)对于所有群落而言,物种多样性与地上生物量呈显著正相关关系,不同群落间,除矮嵩草群落外,小嵩草群落和山生柳+金露梅群落的物种丰富度与地上生物量呈显著正相关关系;对于Shannon-Wiener指数与地上生物量的关系,除山生柳+金露梅群落中两者呈显著正相关外,矮嵩草群落和小嵩草群落均没有表现出显著的相关性。(4)对于所有群落,土壤速效氮对物种多样性和地上生物量都有很大的影响,速效氮含量越高,物种多样性越丰富,地上生物量越高。     

呼伦贝尔贝加尔针茅草甸草原 光能利用率变化规律分析

光能利用率（LUE）是植被光合作用的重要概念,也是研究草地生态系统不同尺度的总第一性生 产力（GPP）、净第一性生产力（NPP）估算模型的重要参数之一。该文通过地面遥感测量、暗箱—气相色 谱法（DC-GC）和涡度相关技术（EC）的方法,在2011年8月初至9月初,获取呼伦贝尔地区以贝加尔 针茅为主要优势种的草甸草原光能利用率,并动态分析光能利用率的日变化和季节变化。研究表明,光能 利用率日变化呈先降低后增加的单峰趋势,即在早晚出现较高值,中午出现较低值;光能利用率的季节变 化总体呈下降趋势。日变化研究中光合有效辐射PAR和温度都与光能利用率呈显著负相关;季节变化研究 中,温度与光能利用率呈弱正相关,叶面积指数与光能利用率呈显著正相关。     

青藏高原地区草原生态旅游资源及其SWOT分析*——以若尔盖草原为例

[目的]草原旅游属于草地农业生态系统的前植物生产层,是草地资源开发利用和绿色草产业可持续发展的新方向。青藏高原草原面积巨大,具有地域特色鲜明、动植物资源丰富、文化底蕴深厚、区位优势明显及潜在的生态风险等特点,为了满足草原旅游活动和草原生态保护的双重目的,促进高寒草原旅游的可持续发展。[方法]运用SWOT分析法,以川西北若尔盖草原旅游资源及开发利用为例,对其草原生态旅游资源的优势(S)、劣势(W)、机遇(O)和挑战(T)进行分析。[结果]若尔盖草原旅游产业具有品牌、资源、区位和知名度四大优势,并存季节性不平衡、基础设施不完善和体验性较差三大劣势,具有国家及地方政策规划、公众追求自然回归原始需求的两大机遇,同时面临草地资源保护     

内蒙古退耕土地生态建设调查与思考

调查了内蒙古土地开垦与退垦情况解放后出现4次开荒高潮,共开垦5700多万亩.全区近10年开垦草原587万亩、林地735万亩,水土流失面积超过4亿亩,导致生态环境恶化,土地荒漠化扩展.论述了退耕的必要性、可行性,及退耕后的实效;提出问题及措施建议.     

草原蘑菇圈生态学研究进展

[目的]蘑菇圈真菌是草原生态系统的重要组成部分,作为分解者参与草原生态系统的物质循环与能量流动,也是重要的生物多样性资源,具有重要的食用及药用价值。文章梳理了涉及草原蘑菇圈特征、机理和影响等研究文献,总结了近年来的研究成果,提出了今后研究设想,为后续研究提供一定的参考。[方法]按照“蘑菇圈分布、类型、机制以及其对植物、土壤和微生物的作用”这一逻辑,以文献综述法对相关文献进行综述。[结果]通过对现有国内外文献进行系统梳理,总结了草原蘑菇圈的类型和分布,蘑菇圈发育的生理生态学机理,蘑菇圈对牧草产量和品质的影响以及其对土壤理化性质和土壤微生物的影响。[结论]蘑菇圈是植物,土壤和真菌/微生物三者之间相互作用的结果,蘑菇圈真菌直接或间接改变了土壤理化性质,微生物群落及酶活性,并可通过化感作用或与植物间形成菌根/寄生关系,其分泌物或裂解后的产物刺激植物生长或杀灭植物,从而促进或抑制植物生长。     

Rewilding and restoring cultural landscapes in Mediterranean mountains: Opportunities and challenges

Farmland abandonment and the decline of livestock activity in the Mediterranean mountains have resulted in dramatic landscape changes, including the generalized expansion of shrublands and forests, and the homogenization of the old cultural landscapes. This process has a variety of consequences from ecological, geomorphological and hydrological points of view, as well as from the perspectives of land management and public awareness. An intense debate currently surrounds the discussion and evaluation of rewilding (the process of passively allowing woody encroachment, as well as the reintroduction of large mammals) as an opportunity for enhancing biodiversity and restoring original landscapes after centuries of human activity versus ecological restoration (activities leading to the recovery of degraded ecosystems, including clearing and light human activity). There is no clear consensus regarding the best way to improve the ecological relationships and functioning within an ecosystem. Biodiversity and sustainability can be seen under different levels of human pressure and landscape transformation; total farmland abandonment is not always the best alternative, particularly when local inhabitants aim to sustain themselves using local resources. Many geographers and ecologists consider that extensive stockbreeding in a partially open landscape is a rational way to (i) improve landscape organization, (ii) increase flows and turnover within the ecosystems, (iii) increase the diversity of plants and animals that benefit from a relatively light human presence, and (iv) reduce wildfire risk. However, it has proven challenging for land managers and stockbreeders to clear the best old abandoned fields and “construct” a sustainable, balanced landscape that combines forests, shrublands and open lands. Private landowner involvement and support from the general public is crucial for both funding and the long-term maintenance of benefits. The best old fields should be cleared in the context of high-resolution knowledge of the topography, grassland characteristics, grassland cycles and livestock management. Such efforts are likely to be an excellent opportunity to introduce compatibility between light human activity and increases in biodiversity and sustainability for many marginal mountains, where land abandonment and general forest/shrub recovery are the inevitable tendencies. This paper examines some of the contrasting positions of the scientific community regarding the rewilding or ecological restoration of mountain landscapes, and briefly highlights some experiences in which intentional clearing of old abandoned fields has benefited stockbreeding, biodiversity, runoff generation and wildfire risks. Notably, we describe a sub-Mediterranean valley of the Iberian Range, Northern Spain, as an example. In the long term, we find that the intentional clearing of the best old fields allows the slow organization of a final landscape that will be more useful for local inhabitants, thereby helping to reverse human depopulation in these regions.     

Study on the abandonment of sloping farmland in Fengjie County,Three Gorges Reservoir Area,a mountainous area in China

The farmland abandonment phenomenon in mountainous areas is a recent change in relationships between man and land that emerged in China's land-use transition. Revealing spatial distribution characteristics and influence factors of sloping farmland (SF) and abandoned farmland (AF) in mountainous areas is conducive to rational allocation and optimization on local land resources. This paper investigated regional distribution features of SF and AF in the hinterland of the Three Gorges Reservoir Area (TGRA) using high-resolution remote sensing images, ArcGIS spatial analysis, and statistical methods. The results found that the spatial distribution of SF and AF has an approximate characteristic under different topography, location, or accessibility backgrounds. However, within different spatial coupling relationships between SF and AF, influencing mechanisms of farmland abandonment are significantly different. The diversity of geographical locations reflecting natural and social contexts is an essential reason for this differentiation. Moreover, dominant influencing factors of farmland abandonment in the study area are natural factors such as slope and farmland quality. Socioeconomic factors, including distance to road, peasant income, and labor force proportion, guide the distribution and trend of farmland abandonment to varying degrees. Finally, four modes of farmland abandonment in TGRA have proposed and suggested that the corresponding plans for SF consolidation should be proposed based on fine classification, which is of great significance for farmland utilization and rural revitalization in underdeveloped mountainous areas.     

广西合山市煤矿废弃地植被现状调查与分析

通过实地踏查和样方法,调查了合山矿区废弃地的植被组成和自然演替情况。结果表明：该地自然定居植物共87种,隶属于39科61属。主要包括禾本科（14种）、菊科（11种）、豆科（10种）。全部定居植物中,草本植物48种,木本植物34种,藤本植物5种。在废弃早期样地,植被主要是一些单种斑块和小群落,这些小群落组成结构比较简单,物种多样性低,群落不稳定。在废弃时间相对较长的时间里,各样地植被的植物组成相对较丰富,野古草、画眉草、四脉金茅、巴芒、黄茅草、纤毛鸭嘴草、马唐、五节芒等可在煤矿废弃地上成功定植,并成为植被中的先锋种和优势种,可作为废弃地植被恢复治理的优先选用物种。废弃矿区植被具有由裸地→草丛→灌草丛→灌木林演替的趋势,并且随着废弃时间的增长,群落中物种丰富度增大,多样性指数呈增加趋势。在10~15年的废弃时间内群落可自然恢复,程度可以逐步达到相对稳定的灌草群丛。研究结果为矿山生态恢复提供了参考依据。     

我国耕地撂荒机理及盘活对策研究

基于遥感与抽样调查结合等手段从高分影像获取的2017年全国耕地撂荒数据表明,现阶段我国耕地撂荒呈现撂荒面积、撂荒率双增长,撂荒现象趋于普遍和由贫瘠、破碎地块向肥沃、连片耕地蔓延的新特征。自然环境、经济、社会、政策与制度都是当前城镇化进程中耕地撂荒趋势加剧的诱因。针对当前农户耕地撂荒的动因,撂荒耕地盘活对策:一是改善农田基础条件与设施,提升耕地综合质量;二是因地制宜调整耕地布局与产业结构,发展特色农业;三是推行多元化土地使用权转让,推进规模化经营;四是创新农产品销售、流通渠道,加速农产品市场价值转换;五是推行社区型、中心村型整合,全面实现乡村振兴目标;六是开展耕地撂荒盘活试验示范,分区分步组织实施。     

生态退耕背景下黄河流域耕地变化与农业生产和生态环境关系研究

[目的]分析生态退耕背景下黄河流域耕地的时空变化特征,探讨黄河流域不同区域耕地变化与农业生产和生态环境的相互关系,旨在为黄河流域农业绿色发展和耕地利用政策提供借鉴。[方法]文章基于2000—2020年黄河流域连续土地利用数据,利用面板格兰杰因果检验和双变量空间自相关量化耕地变化与农业生产、生态环境之间的动态因果及空间交互关系。[结果](1) 2000—2020年黄河流域年均减少耕地69.53万hm²,还林还草是耕地主要减少去向,2020年和2004年是退耕还林还草高峰年,中上游是退耕还林还草重点区;(2)从格兰杰因果检验来看,下游地区退耕还林还草对农业生产和生态环境没有显著影响,上游地区长期退耕还林还草对农业产值增加有利,中游粮食产量和生态系统服务供给低的地区退耕还林还草更多,中上游生态退耕对生态环境有显著促进作用;(3)从空间自相关结果来看,下游地区退耕与农业生产和生态环境的空间分布不具有一致性,黄土高原南部和太行山附近退耕还林还草与生态环境指标呈高—高集聚,鄂尔多斯高原地区退耕与农业产值呈小范围高—高集聚。[结论]退耕还林还草是黄河流域耕地变化的重要原因,退耕...     

Determinants of cropland abandonment at the parcel,household and village levels in mountain areas of China: A multi-level analysis

Cropland abandonment accompanying economic development has been observed worldwide. China has experienced a large amount of land abandonment in recent years. However, the reasons for it are not entirely clear. Although abandonment decisions are made by individual households, the underlying conditions reflect processes operating at multiple levels. Therefore, we aimed to detect the influences on land abandonment at the parcel, household and village levels. We developed and employed a multi-level statistical model using farm household survey data and geographical maps of Wulong County. Our model revealed that of the variance in occurrence of land parcel abandonment, 7% and 13% can be explained at the household and village levels, respectively, while the remnant 80% can be explained at the land parcel features itself. We found that land abandonment is more prone to occur on parcels that are on steep slopes, have poor quality soil, or are remote from the laborers’ residences. Households with less agricultural labor per unit land area showed a high probability of land abandonment. We also found a nonlinear influence of labor age on land abandonment, with households comprising middle-aged laborers having a low land abandonment probability. Parcels in villages with high elevation, far from the county administrative center or with low prevalence of leased land are inclined to abandonment. We also found, surprisingly, that the household proportion of males among its agricultural laborers did not significantly influence the occurrence of land abandonment at the parcel level, probably due to the male agricultural laborers being overwhelmingly old (average age greater than 56 years). To alleviate land abandonment, we suggest improving land tenure and transfer security to ensure stable access to the land rental market, and also improving infrastructure in remote regions.