Current global response insufficient;. Further Information on Key Issues from the Report Scale of Loss of Nature Gains from societal and policy responses, while important, have not stopped massive losses. Since , trends in agricultural production, fish harvest, bioenergy production and harvest of materials have increased, in response to population growth, rising demand and technological development, this has come at a steep price, which has been unequally distributed within and across countries.
The pace of agricultural expansion into intact ecosystems has varied from country to country. Losses of intact ecosystems have occurred primarily in the tropics, home to the highest levels of biodiversity on the planet. For example, million hectares of tropical forest were lost from to , resulting mainly from cattle ranching in Latin America about 42 million hectares and plantations in South-East Asia about 7. Since the global human population has more than doubled from 3.
Indigenous Peoples, Local Communities and Nature At least a quarter of the global land area is traditionally owned, managed, used or occupied by Indigenous Peoples.
Regional and global scenarios currently lack and would benefit from an explicit consideration of the views, perspectives and rights of Indigenous Peoples and Local Communities, their knowledge and understanding of large regions and ecosystems, and their desired future development pathways.
Recognition of the knowledge, innovations and practices, institutions and values of Indigenous Peoples and Local Communities and their inclusion and participation in environmental governance often enhances their quality of life, as well as nature conservation, restoration and sustainable use.
Their positive contributions to sustainability can be facilitated through national recognition of land tenure, access and resource rights in accordance with national legislation, the application of free, prior and informed consent, and improved collaboration, fair and equitable sharing of benefits arising from the use, and co-management arrangements with local communities.
Policy Tools, Options and Exemplary Practices Policy actions and societal initiatives are helping to raise awareness about the impact of consumption on nature, protecting local environments, promoting sustainable local economies and restoring degraded areas. Together with initiatives at various levels these have contributed to expanding and strengthening the current network of ecologically representative and well-connected protected area networks and other effective area-based conservation measures, the protection of watersheds and incentives and sanctions to reduce pollution.
The Report presents an illustrative list of possible actions and pathways for achieving them across locations, systems and scales, which will be most likely to support sustainability. Taking an integrated approach: In agriculture , the Report emphasizes, among others: promoting good agricultural and agroecological practices; multifunctional landscape planning which simultaneously provides food security, livelihood opportunities, maintenance of species and ecological functions and cross-sectoral integrated management.
It also points to the importance of deeper engagement of all actors throughout the food system including producers, the public sector, civil society and consumers and more integrated landscape and watershed management; conservation of the diversity of genes, varieties, cultivars, breeds, landraces and species; as well as approaches that empower consumers and producers through market transparency, improved distribution and localization that revitalizes local economies , reformed supply chains and reduced food waste.
In marine systems , the Report highlights, among others: ecosystem-based approaches to fisheries management; spatial planning; effective quotas; marine protected areas; protecting and managing key marine biodiversity areas; reducing run- off pollution into oceans and working closely with producers and consumers. In freshwater systems , policy options and actions include, among others: more inclusive water governance for collaborative water management and greater equity; better integration of water resource management and landscape planning across scales; promoting practices to reduce soil erosion, sedimentation and pollution run-off; increasing water storage; promoting investment in water projects with clear sustainability criteria; as well as addressing the fragmentation of many freshwater policies.
In urban areas , the Report highlights, among others: promotion of nature-based solutions; increasing access to urban services and a healthy urban environment for low-income communities; improving access to green spaces; sustainable production and consumption and ecological connectivity within urban spaces, particularly with native species.
Even iconic and once abundant species such as the Tasmanian Devil are now on the brink of oblivion. Recent studies in Europe have demonstrated that the species currently at highest risk of extinction most likely got that way because of human actions 50 to years ago.
But you may also have noticed that under the big trees there are often no little trees. Hence, when the big trees die, as they inevitably will , there will be nothing to replace them. If we want to avert extinctions from our legacies we will need to direct conservation efforts most into areas carrying the highest debts. But why should it matter to us if we have a few less species? The simple answer is that we are connected to and deeply dependent on other species.
From pollination of our crops by bees , to carbon storage by our forests, and even the bacteria in our mouths , we rely upon biodiversity for our very existence. We neglect this at our own peril. And of course there are equally justified arguments for keeping species based purely on their aesthetic and cultural importance, or for their own sake.
Doom-and-gloom predictions tend to paralyse us, rather than jolting us into action. So what can be done? There are wonderful examples of individuals and organisations working at both small and large scales to tackle and even sometimes turn back the tide of extinctions.
See also the article Overexploitation. Biological, physical and chemical factors in most ecosystems are tightly intertwined. Hence changes in one of these factors can result in changes of others. Exploitation of habitat can therefore profoundly influence many components of a system.
Examples of habitat destruction are:. Recent climate change such as global warming has increased local water temperatures beyond the suitable range of many species. Such changes have made highly productive areas, such as up-welling regions, become less productive due to changes in the food web.
Lower primary production supports a lower biomass of primary consumers. In the oceans, krill are major primary consumers that support many important ecosystems. Therefore climate change will inevitably impact food webs based on krill and this will be reflected in the reduction of top level consumer such as large plankton-grazing fish and sea mammals [12].
See also Climate-induced regime shifts. Habitat destruction is the primary cause for the decline of biodiversity in the East Indian and Central Pacific marine regions. Overexploitation appears to be the primary cause in the Atlantic and Mediterranean regions.
Important, but relatively lesser causes of biodiversity loss are pollution , eutrophication , climate change and invasive species , see Fig. Although every species contributes to the ecosystem function, some species are more vulnerable to extinction and have a greater impact than others. These include:. Top predators also called 'apex predators' play a critical role in ecosystems, by regulating directly and indirectly all underlying trophic levels.
They need a large territory to get sufficient prey and their abundance is relatively low. Reproduction and growth is slower than for smaller species and so is their recovery after partial depletion.
They are a favorite target of the fishery and therefore prone to overfishing [13] [14]. For example, even light fishing pressure is sufficient to cause strong population declines in many large shark species [16]. This 'trophic downgrading' has generated widespread concern because of the fundamental role that apex predators can play in ecosystem functioning, disease regulation, and biodiversity maintenance [17].
Specialized species with a small geographic range are especially vulnerable to disturbance by invasive species and human intervention. These species can fulfill important functions for the local ecosystem, which are lost when they are replaced by non-native generalist species that compete more efficiently on a larger scale [18].
Migratory species need suitable habitats to feed and rest in widely spaced locations. Such species, for example, Dugong Dugong dugon , Loggerhead turtle Caretta caretta , Hawksbill turtle Eretmochelys imbricata and Mediterranean Monk Seal Monachus monachus are very vulnerable if one of their habitats is lost.
Species such as a Tunicate Ciona intestinalis and a Brown bryozoan Bugula neritina normally need several different elements to be in place at very specific times to complete their life cycles, making them vulnerable if there is disruption of any single element in the cycle.
Species extinction at local or regional scales implies in general a decline in species richness number of species and a decline in biodiversity.
There is strong evidence that species richness in an area enhances ecosystem productivity and stability [19] [20] [21] [22]. The loss of any species can be detrimental to the ecosystem. This is especially true of the loss of species from the higher trophic levels that suffer the greatest risk of local extinction as a result of hunting by humans, loss of habitat or bioaccumulation of toxins.
Loss of top predators can result in a so-called trophic cascade - a complete restructuring of the ecosystem and the food web relationships. Reintroduction of lost species is not always possible, as return is prevented by species that have taken their niche in the food web see the article Trophic cascade for an example. Invasion of alien species can in some cases compensate for a decline in species diversity see the article Non-native species invasions.
However, most alien invasions are by species from lower trophic levels. The structure of marine food webs then changes from a trophic pyramid covered by a diverse array of predators and consumers to a shorter, squatter configuration dominated by filter feeders and scavengers [23]. The loss of filtering services has the potential to increase the risks of harmful algal blooms e. Moreover, the loss of coastal habitats has also resulted in historical losses of floodplain buffer area and loss of erosion control from coastal wetlands, thus increasing flooding risks to coastal inhabitants [25].
The importance of biodiversity in maintaining a stable ecosystem implies that species extinction should be avoided. Several measures can contribute to this objective. These designated areas help to protect depleted, threatened, rare or endangered species and populations, as well as to preserve habitats of critical species.
In addition, only part of the MPAs offer full protection.
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