Study on difference of outburst elimination effect between sub-layers of soft coal and hard coal under the condition of gas per-drainage

The effect of drainage and outburst elimination are obviously different between soft and hard coal sub-layers under per-drainage of coal seam, and hence, the location of per-drainage borehole related to the soft sub-layer is the key that determines whether the outburst can be eliminated in whole coal seam. This paper discusses the differences between soft and hard coal from fields of pore radius distribution, pore structure, surface area and permeability, and the per-drainage effect was numerical simulated under different distance between per-drainage hole and soft sub-layer. Moreover, the optimum hole arrangement of outburst elimination is given in the paper. The result of research shows that the macro-pore with aperture that is larger than 50,000 nm, is dominant at about 50% in hard coal, correspondingly, the micro-pore with aperture less than 100 nm accounts for about 41.23% in soft coal. The surface area of soft coal is 1.6 times as that of hard coal. The residual gas content in soft coal sub-layer is obviously more than it in hard coal sub-layer under the same pre-drainage condition. To 5.5 m-thick coal seams which top is a soft coal sub-layer of 0.5 m-thick, pre-drainage gas can eliminate danger of gas outburst in whole coal seam at the seam time after 455 days drainage when the per-drainage holes are 1.0 m distances from the soft coal sub-layer.     

Past and Present Effectiveness of Protected Areas for Conservation of Naturally and Anthropogenically Rare Plant Species

Abstract:  The Global Strategy of Plant Conservation states that at least 60% of threatened plant species should be within protected areas. This goal has been met in some regions with long traditions of plant protection. We used gap analysis to explore how particular groups of species of conservation interest, representing different types of natural or anthropogenic rarity, have been covered by protected areas on a national scale in Estonia during the last 100 years. Species-accumulation curves indicated that plant species that are naturally rare (restricted global or local distribution, always small populations, or very rare habitat requirements) needed almost twice as many protected areas to reach the 60% target as plant species that are rare owing to lack of suitable management (species depending on grassland management, moderate forest disturbances, extensive traditional agriculture, or species potentially threatened by collecting). Temporal analysis of the establishment of protected areas suggested that grouping plant species according to the predominant cause of rarity accurately reflected the history of conservation decision making. Species found in very rare habitats have previously received special conservation attention; species dependent on traditional extensive agriculture have been largely ignored until recently. Legislative initiative and new nature-protection schemes (e.g., Natura 2000, network of protected areas in the European Union) have had a positive influence on all species groups. Consequently, the species groups needing similar action for their conservation are sensitive indicators of the effectiveness of protected-area networks. Different species groups, however, may not be uniformly conserved within protected areas, and all species groups should fulfill the target of 60% coverage within protected areas.     

Warfare in Biodiversity Hotspots

Abstract:  Conservation efforts are only as sustainable as the social and political context within which they take place. The weakening or collapse of sociopolitical frameworks during wartime can lead to habitat destruction and the erosion of conservation policies, but in some cases, may also confer ecological benefits through altered settlement patterns and reduced resource exploitation. Over 90% of the major armed conflicts between 1950 and 2000 occurred within countries containing biodiversity hotspots, and more than 80% took place directly within hotspot areas. Less than one-third of the 34 recognized hotspots escaped significant conflict during this period, and most suffered repeated episodes of violence. This pattern was remarkably consistent over these 5 decades. Evidence from the war-torn Eastern Afromontane hotspot suggests that biodiversity conservation is improved when international nongovernmental organizations support local protected area staff and remain engaged throughout the conflict. With biodiversity hotspots concentrated in politically volatile regions, the conservation community must maintain continuous involvement during periods of war, and biodiversity conservation should be incorporated into military, reconstruction, and humanitarian programs in the world's conflict zones.     

近距离上保护层开采最小安全岩柱厚度研究

运用岩石力学知识和数值模拟方法,分析近距离保护层矩形掘进巷道周边的应力分布规律以及巷道塑性区范围的确定方法,并结合平煤集团五矿的保护层开采条件,利用FLAC数值计算程序对该矿近距离上保护层掘进期间不同岩柱厚度条件下的保护层底板塑性破坏范围进行数值模拟,在此基础上,提出合理确定保护层底板安全岩柱厚度的方法,现场观测结果表明,理论计算与数值模拟结果比较吻合,符合生产实际。     

自然保护地的文化景观价值演变与识别—以泰山为例

中国的自然保护地具有生态和文化双重价值,文化景观作为自然与文化的交界面,如何识别其价值对中国自然保护地的管理至关重要。以泰山为例,通过古籍文献和实地勘察等方法,从历时性角度对泰山的文化景观价值演变进行剖析。研究发现,泰山文化景观价值经历了山岳崇拜的自然价值、君权神授的政治价值、佛道信仰的宗教价值、祭祀游居的民俗价值及保护利用的综合价值五个阶段。结论认为：自然保护地文化景观价值的演变具有一定的规律性：名山自然保护地的文化景观价值演变是从自然到文化再到综合、从御到民、从单一到多元、从分离到融合的过程;自然保护地文化景观价值的构成要素包括思想基础、环境条件、行为方式及空间结果四部分,具有鲜明的完整性、系统性和动态性特征。文章还对自然保护地文化景观价值的识别策略进行了讨论,为相应类型的国家公园和其他类型自然保护地建设提供参考。     

Temperature niche composition change inside and outside protected areas under climate warming

Conservation of biodiversity relies heavily on protected areas but their role and effectiveness under a warming climate is still debated. We estimated the climate-driven changes in the temperature niche compositions of bird communities inside and outside protected areas in southern Canada. We hypothesized that communities inside protected areas include a higher proportion of cold-dwelling species than communities outside protected areas. We also hypothesized that communities shift to warm-dwelling species more slowly inside protected areas than outside. To study community changes, we used large-scale and long-term (1997–2019) data from the Breeding Bird Survey of Canada. To describe the temperature niche compositions of bird communities, we calculated the community temperature index (CTI) annually for each community inside and outside protected areas. Generally, warm-dwelling species dominated communities with high CTI values. We modeled temporal changes in CTI as a function of protection status with linear mixed-effect models. We also determined which species contributed most to the temporal changes in CTI with a jackknife approach. As anticipated, CTI was lower inside protected areas than outside. However, contrary to our expectation, CTI increased faster over time inside than outside protected areas and warm-dwelling species contributed most to CTI change inside protected areas. These results highlight the ubiquitous impacts of climate warming. Currently, protected areas can aid cold-dwelling species by providing habitat, but as the climate warms, the communities’ temperature compositions inside protected areas quickly begin to resemble those outside protected areas, suggesting that protected areas delay the impacts of climate warming on cold-dwelling species.     

Evaluating the conservation impact of Antarctica's protected areas

Antarctic specially protected areas (ASPAs) are a key regulatory mechanism for protecting Antarctic environmental values. Previous evaluations of the effectiveness of the ASPA system focused on its representativeness and design characteristics, presenting a compelling rationale for its systematic revision. Upgrading the system could increase the representation of values within ASPAs, but representation alone does not guarantee the avoided loss or improvement of those values. Identifying factors that influence the effectiveness of ASPAs would inform the design and management of an ASPA system with the greatest capacity to deliver its intended conservation outcomes. To facilitate evaluations of ASPA effectiveness, we devised a research and policy agenda that includes articulating a theory of change for what outcomes ASPAs generate and how; building evaluation principles into ASPA design and designation processes; employing complementary approaches to evaluate multiple dimensions of effectiveness; and extending evaluation findings to identify and exploit drivers of positive conservation impact. Implementing these approaches will enhance the efficacy of ASPAs as a management tool, potentially leading to improved outcomes for Antarctic natural values in an era of rapid global change. Evaluación del impacto de conservación de las áreas protegidas de la Antártida     

Effects of Oil‐Palm Plantations on Diversity of Tropical Anurans

Agriculturally altered vegetation, especially oil‐palm plantations, is rapidly increasing in Southeast Asia. Low species diversity is associated with this commodity, but data on anuran diversity in oil‐palm plantations are lacking. We investigated how anuran biological diversity differs between forest and oil‐palm plantation, and whether observed differences in biological diversity of these areas is linked to specific environmental factors. We hypothesized that biological diversity is lower in plantations and that plantations support a larger proportion of disturbance‐tolerant species than forest. We compared species richness, abundance, and community composition between plantation and forest areas and between site types within plantation and forest (forest stream vs. plantation stream, forest riparian vs. plantation riparian, forest terrestrial vs. plantation terrestrial). Not all measures of biological diversity differed between oil‐palm plantations and secondary forest sites. Anuran community composition, however, differed greatly between forest and plantation, and communities of anurans in plantations contained species that prosper in disturbed areas. Although plantations supported large numbers of breeding anurans, we concluded the community consisted of common species that were of little conservation concern (commonly found species include Fejervarya limnocharis, Microhyla heymonsi, and Hylarana erythrea). We believe that with a number of management interventions, oil‐palm plantations can provide habitat for species that dwell in secondary forests. Efectos de las Plantaciones de Palma de Aceite sobre la Diversidad de Anuros Tropicales Faruk et al.     

深井厚煤层大巷孤立煤体冲击危险性评价研究*

为了探究大采深条件下厚煤层大巷孤立煤体频繁发生冲击地压的原因,以梁宝寺煤矿35000采区为工程背景,采取现场实践、数值模拟等方法分析不同采深、煤厚、大巷间距等因素对大巷孤立煤体冲击地压的影响,提出深井厚煤层大巷孤立煤体冲击地压的危险性评价方法。研究结果表明:大巷孤立煤体的采深与垂直应力峰值呈正相关,采深1 200 m时煤体的垂直应力峰值是采深500 m时的3倍左右;大巷孤立煤体随着煤层厚度的增加,其应力集中程度不断升高,且应力峰值向煤体弹性承载区转移;大巷间距越小,孤立煤体弹性承载区应力越集中,发生冲击地压可能性越高;包含开采影响因素和煤层冲击倾向性的大巷孤立煤体冲击危险性评价方法符合现场实际情况,可为大巷孤立煤体冲击危险性评价提供1种思路。     

湖北省自然保护区发展态势与对策研究

湖北省自然保护区建设十分迅速，目前已发展到50余个，占全省国土面积的5．85％。系统分析了湖北省自然保护区的发展态势，并针对保护工作中存在的问题，提出了今后的发展思路与建议。