Ecosystems in the context of "Nature-based solutions"

Environmental degradation is the deterioration of the environment through depletion of resources such as quality of air, water and soil; the destruction of ecosystems; habitat destruction; the extinction of wildlife; and pollution. It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable. The environmental degradation process amplifies the impact of environmental issues which leave lasting impacts on the environment.

Environmental degradation is one of the ten threats officially cautioned by the High-level Panel on Threats, Challenges and Change of the United Nations. The United Nations International Strategy for Disaster Reduction defines environmental degradation as "the reduction of the capacity of the environment to meet social and ecological objectives, and needs".

The Neretva (pronounced [něreːtʋa], Serbian Cyrillic: Неретва), also known as Narenta, is one of the largest rivers of the eastern part of the Adriatic basin. Four hydroelectric power plants with large dams (higher than 15 metres) provide flood protection, electricity and water storage. The Neretva is recognized for its natural environment and diverse landscapes.

Freshwater ecosystems have suffered from an increasing population and the associated development pressures. One of the most valuable natural resources of Bosnia and Herzegovina and Croatia is its freshwater resource, contained by an abundant wellspring and clear rivers. Situated between the major regional rivers (Drina river on the east, Una river on the west and the Sava river) the Neretva basin contains the most significant source of drinking water.

Greece is characterized by an extremely fragmented, rugged landscape hosting a great diversity of ecosystems and an outstanding biodiversity. Almost 5% of its extensive coastline consists of ecologically sensitive wetlands. Two thirds of the total population live no further than 2 km from the coast and most of the important urban centers are coastal, while almost all of the tourist infrastructure is divided among islands and the coastal mainland.

In ecology, a marsh is a wetland that is dominated by herbaceous plants rather than by woody plants. More in general, the word can be used for any low-lying and seasonally waterlogged terrain. In Europe and in agricultural literature low-lying meadows that require draining and embanked polderlands are also referred to as marshes or marshland.

Marshes can often be found at the edges of lakes and streams, where they form a transition between the aquatic and terrestrial ecosystems. They are often dominated by grasses, rushes or reeds. If woody plants are present they tend to be low-growing shrubs, and the marsh is sometimes called a carr. This form of vegetation is what differentiates marshes from other types of wetland such as swamps, which are dominated by trees, and mires, which are wetlands that have accumulated deposits of acidic peat.

The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is atmospheric nitrogen, making it the largest source of nitrogen. However, atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems.

The nitrogen cycle is of particular interest to ecologists because nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition. Human activities such as fossil fuel combustion, use of artificial nitrogen fertilizers, and release of nitrogen in wastewater have dramatically altered the global nitrogen cycle. Human modification of the global nitrogen cycle can negatively affect the natural environment system and also human health.

Ecoregions (ecological regions) are ecological and geographic areas that exist on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species. The biodiversity of flora, fauna and ecosystems that characterise an ecoregion tends to be distinct from that of other ecoregions. In theory, biodiversity or conservation ecoregions are relatively large areas of land or water where the probability of encountering different species and communities at any given point remains relatively constant, within an acceptable range of variation (largely undefined at this point).Ecoregions are also known as "ecozones" ("ecological zones"), although that term may also refer to biogeographic realms.

Three caveats are appropriate for all bio-geographic mapping approaches. Firstly, no single bio-geographic framework is optimal for all taxa. Ecoregions reflect the best compromise for as many taxa as possible. Secondly, ecoregion boundaries rarely form abrupt edges; rather, ecotones and mosaic habitats bound them. Thirdly, most ecoregions contain habitats that differ from their assigned biome. Biogeographic provinces may originate due to various barriers, including physical (plate tectonics, topographic highs), climatic (latitudinal variation, seasonal range) and ocean chemical related (salinity, oxygen levels).

A keystone species is a species that has a disproportionately large effect on its natural environment relative to its abundance. The concept was introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether. Some keystone species, such as the wolf and lion, are also apex predators.

The role that a keystone species plays in its ecosystem is analogous to the role of a keystone in an arch. While the keystone is under the least pressure of any of the stones in an arch, the arch still collapses without it. Similarly, an ecosystem may experience a dramatic shift if a keystone species is removed, even though that species was a small part of the ecosystem by measures of biomass or productivity.It became a popular concept in conservation biology, alongside flagship and umbrella species. Although the concept is valued as a descriptor for particularly strong inter-species interactions, and has allowed easier communication between ecologists and conservation policy-makers, it has been criticized for oversimplifying complex ecological systems.

Ecosystem diversity deals with the variations in ecosystems within a geographical location and its overall impact on human existence and the environment.

Ecosystem diversity addresses the combined characteristics of biotic properties which are living organisms (biodiversity) and abiotic properties such as nonliving things like water or soil (geodiversity). It is a variation in the ecosystems found in a region or the variation in ecosystems over the whole planet. Ecological diversity includes the variation in both terrestrial and aquatic ecosystems. Ecological diversity can also take into account the variation in the complexity of a biological community, including the number of different niches, the number of and other ecological processes. An example of ecological diversity on a global scale would be the variation in ecosystems, such as deserts, forests, grasslands, wetlands and oceans. Ecological diversity is the largest scale of biodiversity, and within each ecosystem, there is a great deal of both species and genetic diversity.

Regeneration in biology is the process of renewal, restoration, and tissue growth that makes genomes, cells, organisms, and ecosystems resilient to natural fluctuations or events that cause disturbance or damage. Every species is capable of regeneration, from bacteria to humans. Regeneration can either be complete where the new tissue is the same as the lost tissue, or incomplete after which the necrotic tissue becomes fibrotic.

At its most elementary level, regeneration is mediated by the molecular processes of gene regulation and involves the cellular processes of cell proliferation, morphogenesis and cell differentiation. Regeneration in biology, however, mainly refers to the morphogenic processes that characterize the phenotypic plasticity of traits allowing multi-cellular organisms to repair and maintain the integrity of their physiological and morphological states. Above the genetic level, regeneration is fundamentally regulated by asexual cellular processes. Regeneration is different from reproduction. For example, hydra perform regeneration but reproduce by the method of budding.