“三生”空间视角下土地利用转型的生态环境效应及驱动力——以甘肃省为例

中国社会经济快速转型背景下土地利用变化所引发的环境问题被广泛关注。以土地利用现状遥感监测数据和统计资料为数据源,借助ArcGIS和SIMCA-P软件平台,基于"三生"空间视角,通过生态环境质量指数测度了1980—2018年甘肃省土地利用转型的生态环境效应,并运用偏最小二乘法揭示生态环境质量演变的驱动机制。研究发现:(1)"三生"空间结构演化和地域分异显著。生产、生活空间集中分布于河西走廊、陇中和陇东黄土高原并呈扩张态势;生态空间主要分布于陇南山地、甘南高原、祁连山地和河西走廊以北地带且整体呈缩减趋势;生产、生活空间的增长源于对生态空间的侵占。(2)生态环境质量改善和恶化趋势并存,整体上经历了先下降后上升的"U"形演化过程;空间上呈"东南高-西北低"的分布特征,空间格局演化具有明显的集聚性。(3)生态建设、科技进步等对生态环境改善具有明显的促进作用;而人口增加、社会消费水平提升在一定程度上加剧了生态环境压力;对外贸易对生态环境的影响具有双面性。     

国家重点生态功能区城市与毗邻非生态功能区城市绿色发展水平测度与时空差异

以黑龙江省为主体的中国北方森林湿地生态功能区及毗邻地区作为实证研究区域,从绿色生产、绿色生活、绿色生态三个维度构建绿色发展水平测度指标体系,运用熵权-TOPSIS评价法、障碍度模型、趋势移动平均模型等方法,对2009—2018年期间长白山森林生态功能区、三江平原湿地生态功能区、大小兴安岭森林生态功能区及毗邻的非生态功能对照区绿色发展水平进行了动态测度和时空差异比较、评估了绿色转型发展速度、识别并分析了障碍因素作用,预测了绿色发展趋势水平。主要结论如下：(1)区域自然生态本底优质,但各功能区绿色发展水平相对较低,绿色指数均低于0.6;十年间各功能区绿色发展水平呈小幅上升趋势。城市间绿色发展整体水平的最大差距徘徊在0.16—0.17之间,呈微弱缩小态势。(2)从3个时间节点各功能区整体绿色发展空间格局上看,长白山森林生态功能区处于较高水平,三江平原湿地生态功能区水平偏低。大小兴安岭森林生态功能区绿色发展水平上升幅度较大,毗邻对照区则较小。高水平类型城市数量有所增加,由1个增加至3个,低水平地区数量下降,由4个下降至2个,并呈向高水平转变的趋势。(3)区域绿色转型效果总体不显著,转型速度缓慢...     

中国农业系统近40年温室气体排放核算

基于排放因子法构建了包含种植业和牲畜养殖业的农业系统温室气体排放核算体系,系统核算了1980-2020年我国全国尺度上的农业系统温室气体排放总量和变化趋势,并在区县级尺度下对1980、2000、2011年的中国农业系统的温室气体排放量进行核算,对比不同阶段农业系统温室气体排放变化的时空异质性规律。研究发现：1980-2020年我国农业系统温室气体排放量呈波动增长趋势,增长了近46%。CH₄是农业系统排放贡献最大的温室气体,占总排放量的47.33%。我国农业系统温室气体排放与不同地区农业生产方式有关,CH₄排放量高的地区主要位于我国主要水稻产区以及旱地作物产区。CO₂排放量高的地区主要位于东北、西北等地区以及华东地区。N₂O排放量较高地区主要位于西北的主要畜牧养殖地区,以及我国农业经济发展水平高的中南部地区。研究有助于揭示我国农业温室气体排放的动态特征,现状规律,以及空间差异性特征,从农业减排角度为实现双碳目标提供科学参考。     

长株潭城市群生态屏障研究

构筑城市(群)生态屏障是我国生态建设的重点之一。高速城市化进程中,城市范围、征用土地、人口数量、建设规模不断扩大,生态安全形势日益严峻,生态环境保护压力不断加大。长株潭城市群是国家"两型"社会建设试验区,生态屏障建设备受关注。在广泛开展社会调研、专项调查、专题研究、学术讨论的基础上,根据景观生态学和保护生物学的相关原理,通过对区域生态压力、需求、承载力的分析,借助RS、GIS、GPS等现代高新技术,科学区划长株潭城市群生态屏障的空间层级、结构、布局、功能区,明确了各功能区的建设方向、目标,提出了分区管理和分级保护等具体空间管治措施,规划2020年前保护建设工程项目。研究结果表明,城市群必须根据生态环境承载能力,按生态隔离组团方式科学布局城市空间,预留足够的生态基地,优先构筑稳固的生态屏障;按照主体功能区划和目标定位,严格管治和合理布局生态用地,加强部门规划统筹协调,依法严格保护森林和湿地;加强公共财政转移支付和社会融资力度,抓紧实施生态屏障工程建设,努力改善环境质量,维护区域生态平衡,努力实现资源节约、环境友好、提高城市品位和综合竞争能力的社会发展目标。研究结果可为城市生态屏障建设提供科学方法和依据,同时也可为全国其它城市(群)生态屏障建设提供参考和借鉴。     

Patterns of intra- and interspecific association in leaf-mining insects on three oak host species

Abstract. 1. We determined mortality and distributional patterns of leaf miners on three oak host species (Quercus falcata, Q.nigra and Q.hemisphaerica) in northern Florida, U.S.A.
2. Patterns of intra- and interspecific occurrence within leaves, and mortality of five most abundant leaf miner species were analysed as a test of competition.
3. Miners co-occurred on leaves more often that expected by chance (P<0.05) in six of ten possible species combinations and log-linear model analysis showed no negative higher-order interactions.
4. All five miner species had highly clumped distributions between leaves (P<0.01).
5. Leaf miner survival was less than expected for four of five species when co-occurring on leaves with conspecifics than when mining with heterospecifics or alone (P<0.05).
6. We conclude that interspecific competition is unapparent within this leaf miner guild and that intraspecific competition occurs in four of the five major leaf miner species. We discuss leaf miner selection of common leaves, perhaps based on chemical/physical leaf characters, as a cause of intra- and interspecific aggregation.     

Pre-weaning management of calves on commercial dairy farms and its influence on calf welfare and mortality

Welfare and management of calves is of increasing interest and also influences performance of these animals in later life. The aim of this study was to assess management and environmental conditions under which pre-weaned dairy calves are reared on commercial Irish dairy farms. We included 47 spring-calving, pasture-based herds in this study. Herd and animal-specific data, such as mortality rate, age and breed, were gathered from all participants via the HerdPlus® database. Information pertaining to management practices was collected by conducting an interview with the principal calf rearer, while an assessment of calf housing facilities was conducted to identify conditions calves were reared in. The environmental assessment included measurements of space allowance per calf, as well as feeding equipment hygiene. To assess calf behaviour video observations were used, while accounting for the number of calves present in a group and the space available per calf. Faecal samples were also collected to determine the presence of enteric pathogens among calves. To compare calf space allowance, group size and presence of enteric pathogens early and late in the calving season each farm was visited twice. Calf mortality was not associated with either herd size, space allowance per calf or post-colostrum feeding practices. Higher calf mortality was identified among herds which reported experiencing an on-set of calf pneumonia during weeks 8 to 10 of the calving season. This study demonstrates that factors associated with calf welfare on commercial Irish dairy farms (e.g. space allowance, mortality rate) are independent of herd size. Some management practices however, such as methods used for treating health issues can affect rates of calf mortality experienced. Calf mortality, for example, was lower in herds which treated diarrhoea cases by administering electrolytes, while continuing to offer milk. Behavioural observations indicate that smaller group sizes could promote expression of positive behaviours, potentially resulting from an overall improvement in welfare. Space allowance per calf was not associated with observed behaviour frequencies. We also identified that similar rates of calf mortality are experienced across herds of different sizes.     

国家公园规划制度功能定位与空间属性

我国将构建统一的国土空间规划体系, 整体谋划国土空间开发保护格局, 强化对各类专项规划的指导约束, 这必将对国家公园保护制度产生重大影响。本文分析了国土空间规划视角下国家公园规划制度的定位, 阐述了国家公园规划承载空间规划与发展规划两大体系的基本属性, 应在国土空间规划体系中具有优先权和前置权; 重点分析了各国家公园总体规划在国家规划体系中的功能与属性特征, 作为空间规划应承接好上位空间规划对国家公园的控制指标和管控要求, 作为建设规划应承接好上位或同域国民经济发展规划等对国家公园的目标任务要求, 作为管理规划要明确国家公园顺畅运行的要求。国家公园应在分区规划、控制性详细规划等专项规划方面寻求创新, 探索国家公园用途管制的实现模式。