Bushmeat hunting changes regeneration of African rainforests

To assess ecological consequences of bushmeat hunting in African lowland rainforests, we compared paired sites, with high and low hunting pressure, in three areas of southeastern Nigeria. In hunted sites, populations of important seed dispersers—both small and large primates (including the Cross River gorilla, Gorilla gorilla diehli)—were drastically reduced. Large rodents were more abundant in hunted sites, even though they are hunted. Hunted and protected sites had similar mature tree communities dominated by primate-dispersed species. In protected sites, seedling communities were similar in composition to the mature trees, but in hunted sites species with other dispersal modes dominated among seedlings. Seedlings emerging 1 year after clearing of all vegetation in experimental plots showed a similar pattern to the standing seedlings. This study thus verifies the transforming effects of bushmeat hunting on plant communities of tropical forests and is one of the first studies to do so for the African continent.     

Bushmeat hunting in the Congo Basin: an assessment of impacts and options for mitigation

Hunting of wild animals is an important component of household economies in the Congo Basin. Results from the growing corpus of quantitative studies show that: a) bushmeat remains the primary source of animal protein for the majority of Congo Basin families; b) bushmeat hunting can constitute a significant source of revenue for forest families; c) bushmeat consumption by low density populations living in the forest may be sustainable at present; d) demand for bushmeat by growing numbers of urban consumers has created a substantial market for bushmeat that is resulting in a halo of defaunation around population centres, and may be driving unsustainable levels of hunting, even in relatively isolated regions; and e) large bodied animals with low reproductive rates are most susceptible to over-exploitation compared with more r-selected species that apparently can tolerate relatively intensive hunting (Mangel et al. 1996). As urban populations continue to grow and economies revitalise, unless action is taken to alter the demand for, and the supply of bushmeat, the forests of the Congo Basin will be progressively stripped of certain wildlife species, risking their extirpation or extinction, and the loss of values they confer to local economies. Consequently, it is essential that a) logging companies are encouraged or coerced not to facilitate bushmeat hunting and transportation in their concessions, b) we develop a better understanding of the elasticity of bushmeat demand, c) that pilot bushmeat substitution projects are supported and their impact on demand evaluated, and d) social marketing activities are put in place to attempt to direct consumer preferences for animal protein away from bushmeat species that are particularly susceptible to over-exploitation.     

国家公园生态系统生产总值核算——以海南热带雨林国家公园为例

海南热带雨林国家公园拥有我国最具代表性、连片面积最大的热带雨林,生态产品丰富,在开展国家公园生态产品价值实现机制探索上具有得天独厚的优势。本研究基于《陆地生态系统生产总值(GEP)核算技术指南》框架,构建符合热带雨林国家公园特色的GEP核算体系,对2019年海南热带雨林国家公园GEP进行核算。结果表明: 2019年,海南热带雨林国家公园GEP为2045.13亿元,单位面积GEP为0.46亿元·km^-2。其中,物质产品价值为48.50亿元,占国家公园GEP总量的2.4%;生态系统调节服务价值为1688.91亿元,占82.6%;文化服务价值为307.72亿元,占15.0%。从不同生态系统类型来看,以山地雨林、低地雨林、落叶季雨林、热带云雾林等为代表的热带雨林生态系统的单位面积价值量远高于人工林及其他生态系统,表明热带雨林生态系统在提供生态系统服务功能方面具有显著作用。此外,本研究还基于国家公园GEP核算结果,提出进一步探索生态产品价值实现路径和实现机制的相关建议。     

The bushmeat trade in southwestern Nigeria: A case study

Hunters and bushmeat retailers in Bendel State, Nigeria were interviewed from May through August 1982. Hunting was found to take place in all months of the year, but became more intense during the dry season. Twentyseven species of mammal were reported to be hunted, while 22 species of mammal and five species of reptile were found on sale. Retailers reported that the grasscutter (Thryonomys swinderianuswas the most popular species among their customers, followed by Maxwell's duiker, the brushtailed porcupine, and the bushpig. The grasscutter was also the most widely sold species, followed by the giant rat, monkeys, and Maxwell's duiker. Game animals were found to be shot and sold with little regard to existing laws, with the result that the larger mammals have become rare in Bendel and populations of the smaller ones have come under severe pressure. The bushmeat trade is highly commercialized, and substantial profits accrue to middlemen. Recommendations are made for the conservation of a natural resource, wildlife, that not only provides a significant amount of animal protein but also supports a large rural economy.     

Dung beetle-megafauna trophic networks in Singapore’s fragmented forests

We investigated trophic networks between dung beetles and megafauna species in five forest fragments in Singapore varying in size and isolation. We found that Singapore's dung beetle communities were attracted to extant and extinct dung types from different dietary groups. All forest fragment networks were similar and displayed high generalism and high nestedness.     

Population history and gene dispersal inferred from spatial genetic structure of a Central African timber tree,Distemonanthus benthamianus (Caesalpinioideae)

African rainforests have undergone major distribution range shifts during the Quaternary, but few studies have investigated their impact on the genetic diversity of plant species and we lack knowledge on the extent of gene flow to predict how plant species can cope with such environmental changes. Analysis of the spatial genetic structure (SGS) of a species is an effective method to determine major directions of the demographic history of its populations and to estimate the extent of gene dispersal. This study characterises the SGS of an African tropical timber tree species, Distemonanthus benthamianus, at various spatial scales in Cameroon and Gabon. Displaying a large continuous distribution in the Lower Guinea domain, this is a model species to detect signs of past population fragmentation and recolonization, and to estimate the extent of gene dispersal. Ten microsatellite loci were used to genotype 295 adult trees sampled from eight populations. Three clearly differentiated gene pools were resolved at this regional scale and could be linked to the biogeographical history of the region, rather than to physical barriers to gene flow. A comparison with the distribution of gene pools observed for two other tree species living in the same region invalidates the basic assumption that all species share the same Quaternary refuges and recolonization pathways. In four populations, significant and similar patterns of SGS were detected. Indirect estimates of gene dispersal distances (sigma) obtained for three populations ranged from 400 to 1200 m, whereas neighbourhood size estimates ranged from 50 to 110.     

海南热带雨林国家公园不同植被类型的大型真菌多样性

为揭示海南热带雨林国家公园大型真菌多样性及不同植被类型对真菌群落的影响, 本研究于2020年和2021年湿季对海南热带雨林国家公园内7个管理局辖区开展了大型真菌多样性调查, 比较了不同植被类型(山地雨林、低地雨林、低地雨林次生林、人工林)的大型真菌生活型(共生型、腐生型)组成差异。从设置的58条1 km长的样带内采集到1,869份子实体标本, 根据子实体形态与ITS rDNA序列分析, 从中鉴定出562种真菌, 涉及17目64科174属, 其中80%以上的物种由伞菌目、牛肝菌目、红菇目、多孔菌目、鸡油菌目、锈革孔菌目和炭角菌目构成。大型真菌的营养型以腐生型(占48.2%物种)和共生型(44.8%)为主。每条样带的平均物种丰富度和多度以中海拔的山地雨林最高, 分别为28 ± 5种和33 ± 6个, 而人工林最低, 分别为11 ± 1种和11 ± 2个。植被类型主要影响共生型大型真菌物种丰富度(P = 0.026)和子实体多度(P = 0.019)及Shannon-Wiener多样性(P = 0.028), 但对腐生型大型真菌的影响并不显著。多响应置换过程(multiple response permutation procedure, MRPP)检验结果表明, 不同植被类型对共生型与腐生型大型真菌群落物种组成均有显著影响(腐生型: P = 0.004, 共生型: P = 0.041)。冗余分析(redundancy analysis, RDA)的结果表明, 植被类型对腐生型和共生型真菌群落物种组成差异的解释度均较低(共生型: R² = 0.068, P = 0.004; 腐生型: R² = 0.067, P = 0.004)。海拔仅对腐生型真菌群落物种组成产生微弱影响(R² = 0.029, P = 0.001), 而对共生型真菌影响不显著(R² = 0.024, P = 0.072)。在不同保护地之间, 共生型(R² = 0.148, P = 0.001)与腐生型(R² = 0.123, P = 0.002)真菌物种组成均具显著差异; 基于样带‒真菌矩阵的网络图显示, 海南热带雨林国家公园内尖峰岭、霸王岭、五指山等国家级自然保护区的山地雨林是共生型大型真菌多样性较高区域, 应作为共生型真菌与宿主的优先保护区域。