Environmental Synergisms and Extinctions of Tropical Species

Abstract: Environmental synergisms may pose the greatest threat to tropical biodiversity. Using recently updated data sets from the International Union for Conservation of Nature (IUCN) Red List, we evaluated the incidence of perceived threats to all known mammal, bird, and amphibian species in tropical forests. Vulnerable, endangered, and extinct species were collectively far more likely to be imperiled by combinations of threats than expected by chance. Among 45 possible pairwise combinations of 10 different threats, 69%, 93%, and 71% were significantly more frequent than expected for threatened mammals, birds, and amphibians, respectively, even with a stringent Bonferroni‐corrected probability value (p= 0.003). Based on this analysis, we identified five key environmental synergisms in the tropics and speculate on the existence of others. The most important involve interactions between habitat loss or alteration (from agriculture, urban sprawl, infrastructure, or logging) and other anthropogenic disturbances such as hunting, fire, exotic‐species invasions, or pollution. Climatic change and emerging pathogens also can interact with other threats. We assert that environmental synergisms are more likely the norm than the exception for threatened species and ecosystems, can vary markedly in nature among geographic regions and taxa, and may be exceedingly difficult to predict in terms of their ultimate impacts. The perils posed by environmental synergisms highlight the need for a precautionary approach to tropical biodiversity conservation.     

Logging Concessions Can Extend the Conservation Estate for Central African Tropical Forests

Abstract:  The management of tropical forest in timber concessions has been proposed as a solution to prevent further biodiversity loss. The effectiveness of this strategy will likely depend on species-specific, population-level responses to logging. We conducted a survey (749 line transects over 3450 km) in logging concessions (1.2 million ha) in the northern Republic of Congo to examine the impact of logging on large mammal populations, including endangered species such as the elephant ( Loxodonta africana ), gorilla ( Gorilla gorilla ), chimpanzee ( Pan troglodytes ), and bongo ( Tragelaphus eurycerus ). When we estimated species abundance without consideration of transect characteristics, species abundances in logged and unlogged forests were not different for most species. When we modeled the data with a hurdle model approach, however, analyzing species presence and conditional abundance separately with generalized additive models and then combining them to calculate the mean species abundance, species abundance varied strongly depending on transect characteristics. The mean species abundance was often related to the distance to unlogged forest, which suggests that intact forest serves as source habitat for several species. The mean species abundance responded nonlinearly to logging history, changing over 30 years as the forest recovered from logging. Finally the distance away from roads, natural forest clearings, and villages also determined the abundance of mammals. Our results suggest that logged forest can extend the conservation estate for many of Central Africa's most threatened species if managed appropriately. In addition to limiting hunting, logging concessions must be large, contain patches of unlogged forest, and include forest with different logging histories.     

旋风分离器分离段表状探讨

传统的旋风分离器，由于其分离段形成的内旋气流太混乱，而且剧烈湍动，致使在沉降段已和气体分离的尘粒在分离段中又改变运行方向，重新与气体混在一起，因而除尘效果不理想，为了找到改善分离效果的办法，本文对尘粒的运行过程作数学分析，并对提高除尘效率的旋风分离器分离段形状进行了探讨。     

Shrinking Tropical Forests, Human Agents of Change, and Conservation Policy

Abstract:  Human agents of landscape transformation in the tropics affect forests differently as the forests decline in size. Five agents of change—road builders, corporate concession holders, community forest managers, park advocates, and urban consumers—have different effects on large forests in remote tropical regions than they do on remnant forests in settled agricultural regions. Because forests vary so much in size across tropical regions, these differences in the effects of agents on forests have important implications for regional conservation efforts. To make these implications explicit, I compared the effects of the five agents in regions with large forests with their effects in regions with small forests. The comparisons indicated that, as forests declined in size, new roads no longer destroyed forests, corporate loggers left the forests, community forest managers became more effective, parks became less feasible as a means of conservation, and urban consumers initiated tree planting. My results suggest that awareness about the changing effects of humans on landscapes with shrinking forests can serve as a useful tool in formulating regionally appropriate policies for conserving tropical forests.     

热带海洋大气环境下制动盘防护工艺耐腐蚀性能分析

目的研究汽车制动盘的三种防护工艺在热带海洋大气环境下的耐腐蚀性能。方法针对三种防护工艺的制动盘,在万宁试验站采用户外暴露试验方法开展对比试验。结果某无铬锌铝涂层1防护工艺的制动盘严重生锈,腐蚀程度最严重。某无铬锌铝涂层2和石墨烯防护工艺的制动盘在热带海洋大气环境中发生轻微生锈。结论在热带海洋大气环境下,某无铬锌铝涂层1防护工艺的耐蚀性能最差,某无铬锌铝涂层2和石墨烯防护工艺耐蚀性能良好,具有更好的环境适应性。     

中国炭黑工业大气污染控制

本文研究我国目前炭黑工业大气污染控制技术的状况及特点。近十年来，我国炭黑工业大气污染控制技术有了长足的进展，选择合理的工艺过程，采用袋滤器高效净化炭黑烟气，成功地开发了炭黑工业气体余热的回收及利用。为此，我国炭黑工业大气污染控制技术，实现了炭黑微粒和可燃气态污染物的高效净化，炭黑工业气体余热绝大部分得到了回收及利用，余热利用率达６０％以上。我国炭黑工业一跃成为低能耗、有效能高效利用，大气污染物高效净化的清洁生产的化工厂，和生产热力及电力的能源部门。     

A minority group's response to a severe climatic event: a case study of rural Indo-Fijians after Tropical Cyclone Winston in 2016

This paper investigates the impacts of Tropical Cyclone Winston (2016) on rural Indo-Fijians and their response to the devastation. Studies have previously examined how rural communities in Pacific Island countries respond to severe climatic events, arguing that traditional knowledge of the climate, together with indigenous techniques, contribute substantially to recovery from a disaster. Strong communal bonds have also been identified as an influencing factor. Disaster risk reduction frameworks often assume the availability of such knowledge and capital. Yet, little research has been done on how minority groups with limited access to such knowledge and capital cope with disaster-related damage. The current study shows that rural Indo-Fijians responded to the consequences of Tropical Cyclone Winston differently to indigenous Fijians, owing to relatively limited access to traditional awareness of the climate, communal labour sharing, and intra- and/or inter-community networks. The findings point to the necessity to implement a more inclusive disaster risk reduction framework.     

Use of environmental DNA in assessment of fish functional and phylogenetic diversity

Assessing the impact of global changes and protection effectiveness is a key step in monitoring marine fishes. Most traditional census methods are demanding or destructive. Nondisturbing and nonlethal approaches based on video and environmental DNA are alternatives to underwater visual census or fishing. However, their ability to detect multiple biodiversity factors beyond traditional taxonomic diversity is still unknown. For bony fishes and elasmobranchs, we compared the performance of eDNA metabarcoding and long-term remote video to assess species’ phylogenetic and functional diversity. We used 10 eDNA samples from 30 L of water each and 25 hr of underwater videos over 4 days on Malpelo Island (pacific coast of Colombia), a remote marine protected area. Metabarcoding of eDNA detected 66% more molecular operational taxonomic units (MOTUs) than species on video. We found 66 and 43 functional entities with a single eDNA marker and videos, respectively, and higher functional richness for eDNA than videos. Despite gaps in genetic reference databases, eDNA also detected a higher fish phylogenetic diversity than videos; accumulation curves showed how 1 eDNA transect detected as much phylogenetic diversity as 25 hr of video. Environmental DNA metabarcoding can be used to affordably, efficiently, and accurately census biodiversity factors in marine systems. Although taxonomic assignments are still limited by species coverage in genetic reference databases, use of MOTUs highlights the potential of eDNA metabarcoding once reference databases have expanded.     

Societal change and the control of deforestation in Thailand

Thailand underwent a major shift in forest policy in the second half of the 1980s to promote sustainable management and control of deforestation. This paper puts this in the context of earlier changes in forest policy and analyses the underlying causes of the shift by analysing changes in the relative strength of different interest groups within the framework of a policy pressures model. Internal pressures had a stronger impact on Thai forest policy than external pressures. Protectionist groups became more numerous and more powerful in Thailand in the 1980s in relation to exploitative groups, and their rise in influence was facilitated by continuing progress in democratization and pluralization, linked to the consequences of economic development. Such political change could help to explain the apparent link between better environmental management and economic development shown in the Environmental Kuznets Curve.     

Foreignness as a constraint on learning: The impact of migrants on disaster resilience in small islands

Knowledge about natural hazard management has increased significantly since Gilbert White's seminal research in 1945, yet people are still badly affected by natural hazards. A key question remains in natural hazards research: why, when all the conditions for effective disaster risk reduction are in place, do some people not take action to reduce their risk of harm? Through a questionnaire-based study we investigated the motivating factors that led residents of the Cayman Islands to prepare for annual tropical cyclones (hurricanes). Factors that increase the likelihood of individuals preparing for hurricanes are: previous experience of major storms, having linking networks and ties, having a child under the age of 15 in the home, and residency status—expatriate residents are less likely to prepare. Factors that appear to prevent adaptive behaviour include: living close to or adjacent to the coast, recent migration to the islands, and living in rented accommodation. The findings of the survey confirm that even within societies that are well prepared for tropical cyclones, there are still sub-groups who do not engage with the preparedness process. In the case of the Cayman Islands, new migrants are the most vulnerable to tropical cyclones as they tend to fall into the demographic groups least likely to prepare for cyclones, live in locations with high levels of exposure to cyclone impacts, and interact mostly with other expatriates with no previous experience of cyclone impacts. As climate change promises to bring an increasing intensity of tropical cyclones, these findings have relevance for all islands which draw on migrant workers to support economic growth.