Although the direct impacts of defaunation driven by overhunting can be predicted to some degree, higher-order indirect effects on community structure remain poorly understood since Redford’s (1992) seminal paper and may have profound, long-term consequences for the persistence of other taxa, and the structure, productivity and resilience of terrestrial ecosystems (Cunningham et al. 2009). Severe population declines or extirpation ...

Timber extraction in tropical forests is widely variable in terms of species selectivity, but even highly selective logging can trigger major ecological changes in the understory light environment, forest microclimate, and dynamics of plant regeneration. Even reduced-impact logging (RIL) operations can generate enough forest disturbance, through elevated canopy gap fracture, to greatly augment forest understory desiccation, dry fuel loads, ...

Cascading effects of overexploitation on ecosystems All extractive systems in which the over harvested resource is one or more biological populations, can lead to pervasive trophic cascades and other unintended ecosystem-level consequences to non-target species. Most hunting, fishing, and collecting activities affect not only the primary target species, but also species that are taken accidentally or opportunistically. Furthermore, exploitation often causes physical damage to the ...

Overexploitation in aquatic ecosystems Marine biodiversity loss, largely through overfishing, is increasingly impairing the capacity of the world’s oceans to provide food, maintain water quality, and recover from perturbations (Worm et al. 2006). Yet marine fisheries provide employment and income for 0.2 billion people around the world, and fishing is the mainstay of the economy of many coastal regions; 41 million people worked ...

Non-timber forest products Non-timber forest products (NTFPs) are biological resources other than timber which are extracted from either natural or managed forests (Peters 1994). Examples of exploited plant products include fruits, nuts, oil seeds, latex, resins, gums, medicinal plants, spices, dyes, ornamental plants, and raw materials such as firewood, Desmoncus climbing palms, bamboo and rattan. The socio-economic importance of NTFP harvest to ...

Non-timber forest products Non-timber forest products (NTFPs) are biological resources other than timber which are extracted from either natural or managed forests (Peters 1994). Examples of exploited plant products include fruits, nuts, oil seeds, latex, resins, gums, medicinal plants, spices, dyes, ornamental plants, and raw materials such as firewood, Desmoncus climbing palms, bamboo and rattan. The socio-economic importance of NTFP harvest to ...

Tropical forest vertebrates Humans have been hunting wildlife in tropical forests for over 100 000 years, but the extent of consumption has greatly increased over the last few decades. Tropical forest species are hunted for local consumption or sales in distant markets as food, trophies, medicines and pets. Exploitation of wild meat by forest dwellers has increased due to changes in hunting ...

Tropical forest vertebrates Humans have been hunting wildlife in tropical forests for over 100 000 years, but the extent of consumption has greatly increased over the last few decades. Tropical forest species are hunted for local consumption or sales in distant markets as food, trophies, medicines and pets. Exploitation of wild meat by forest dwellers has increased due to changes in hunting ...

Overexploitation in tropical forests Tropical deforestation is driven primarily by frontier expansion of subsistence agriculture and large development programs involving resettlement, agriculture, and infrastructure. However, animal and plant population declines are typically pre-empted by hunting and logging activity well before the coup de grâce of deforestation is delivered. It is estimated that between 5 and 7 million hectares of tropical forests are logged ...

Overexploitation in tropical forests Tropical deforestation is driven primarily by frontier expansion of subsistence agriculture and large development programs involving resettlement, agriculture, and infrastructure. However, animal and plant population declines are typically pre-empted by hunting and logging activity well before the coup de grâce of deforestation is delivered. It is estimated that between 5 and 7 million hectares of tropical forests are logged ...

A brief history of exploitation Our rapacious appetite for both renewable and non - renewable resources has grown exponentially from our humble beginnings—when early humans exerted an ecological footprint no larger than that of other large omnivorous mammals— to currently one of the main driving forces in reorganizing the structure of many ecosystems. Humans have subsisted on wild plants and animals since the earliest ...

A brief history of exploitation Our rapacious appetite for both renewable and non - renewable resources has grown exponentially from our humble beginnings—when early humans exerted an ecological footprint no larger than that of other large omnivorous mammals— to currently one of the main driving forces in reorganizing the structure of many ecosystems. Humans have subsisted on wild plants and animals since the earliest ...

Overexploitation In an increasingly human-dominated world, where most of us seem oblivious to the liquidation of Earth’s natural resource capital, exploitation of biological populations has become one of the most important threats to the persistence of global biodiversity. Many regional economies, if not entire civilizations, have been built on free-for-all extractive industries, and history is littered with examples of boom ...

Overexploitation In an increasingly human-dominated world, where most of us seem oblivious to the liquidation of Earth’s natural resource capital, exploitation of biological populations has become one of the most important threats to the persistence of global biodiversity. Many regional economies, if not entire civilizations, have been built on free-for-all extractive industries, and history is littered with examples of boom ...

Processes that affect community structure Interactions between species, such as predation, competition, parasitism, and an array of mutualisms, have a profound influence on the structure of communities. The loss of a species or a change in its abundance, particularly for species that interact with many others, can have a marked effect on ecological processes throughout fragmentedlandscapes. Changes to predator-prey relationships, for example, have been ...

Processes that affect community structure Interactions between species, such as predation, competition, parasitism, and an array of mutualisms, have a profound influence on the structure of communities. The loss of a species or a change in its abundance, particularly for species that interact with many others, can have a marked effect on ecological processes throughout fragmentedlandscapes. Changes to predator-prey relationships, for example, have been ...

Patterns of community structure in fragmented landscapes For many taxa birds, butterflies, rodents, reptiles, vascular plants, and more species richness in habitat fragments is positively correlated with fragment size. This is widely known as the species-area relationship. Thus, when habitats are fragmented into smaller pieces, species are lost; and the likely extent of this loss can be predicted from the species-area relationship. Further, species richness in ...

Patterns of community structure in fragmented landscapes For many taxa birds, butterflies, rodents, reptiles, vascular plants, and more species richness in habitat fragments is positively correlated with fragment size. This is widely known as the species-area relationship. Thus, when habitats are fragmented into smaller pieces, species are lost; and the likely extent of this loss can be predicted from the species-area relationship. Further, species richness in ...

Small populations are vulnerable to local extinction, but a species has a greater likelihood of persistence where there are a number of local populations interconnected by occasional movements of individuals among them. Such a set of subdivided populations is often termed a “meta population” (Hanski 1999). Two main kinds of meta population have been described. A mainland-island model is ...

Small populations are vulnerable to local extinction, but a species has a greater likelihood of persistence where there are a number of local populations interconnected by occasional movements of individuals among them. Such a set of subdivided populations is often termed a “meta population” (Hanski 1999). Two main kinds of meta population have been described. A mainland-island model is ...

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