Field of Action Biological Diversity

colourful flowering summer meadowClick to enlarge
Changes in climate can have negative consequences for many species and ecosystems.
Source: patzita/

Impacts of Climate Change

Table of Contents


Changes in the inanimate nature and their effects on flora and fauna

Changes in temperature, changes in precipitation and extreme weather events affect the abiotic living conditions (inanimate nature, such as water, air and land) of plants and animals. If these important conditions change, many animals and plants change their behaviour and characteristics:

  • food relationships are shifting,
  • animals show new patterns of behaviour,
  • periodically recurring growth and developmental processes of plants and animals adapt to the new circumstances,
  • reproductive cycles of animals and plants shift,
  • animals and plants settle in new distribution areas and habitats,
  • native species are increasingly in competition with newly introduced species.

Of course, such changes in the living conditions and behaviour of animals and plants have effects on complex biotopes, habitats and ecosystems.


Effects on species and populations

If the climate changes, this also influences the composition of the communities and the distribution areas of species. Against this background, temperature and precipitation developments have a significant impact on biodiversity.

Especially those species that have a very narrow tolerance range in terms of their living conditions can be affected regarding population size and distribution area or even become extinct. These species can hardly adapt to changing living conditions, since it is almost not possible for them to migrate to new habitats. Species that possess a limited mobility are not able to reach new suitable habitats, also. In Germany, especially habitats for cold and moisture-loving species are becoming scarcer due to climate change. Heat-loving species, on the other hand, will spread out more quickly.

The climate sensitivity of a species also depends on many other factors. These include, among others, biotope binding, site size, current stock situation and reproduction rate.

In addition to the composition of species, a continued climate change may also change the number of species in the communities and biotopes. The increase in temperature and the prolonged growing season allow for an invasion and proliferation of new species, which form new communities or affect the composition of existing communities. Thus, the number of these species may increase in a biotope. However, the invasion of new species can also displace native flora and fauna and thus lead to a shift or even a loss of biodiversity.


Impacts on biotopes, habitats and ecosystems

Biotopes and ecosystems depend on the interaction of different plant and animal species. A modified composition of species and changes in the characteristics and behaviour of individual species threaten this complex interaction.

Since shifts in the life cycles, for example, do not affect all species to an equal extent, species that depend on each other (e.g., predator-prey, flower-pollinator) are decoupled in time and space. Even a change in individual species and small variances of a few days can disturb the ecosystem’s equilibrium and severely disrupt food chains.

An example for such a spatial decoupling are caterpillars of many types of butterflies that depend on the leaves of specific tree species. This correlation is getting lost because of the continuing deviation of the distribution of these animals and plants as a result of climate change.

A temporal decoupling of food chains can be observed in the case of migratory birds. Upon their return in spring, some species no longer find sufficient larvae as food because the insects have already developed at this time.
Different ecosystems are subject to a different sensitivity to climate change. Dry habitats such as dunes, dry grasslands and heathlands are considered to be relatively resistant because they are less sensitive to water deficits. In contrast, moors, swamps, headwater regions and moist grasslands react particularly sensitively to a lack of water.

Also habitats along and in the water are at great risk because the warming and a negative climatic water balance (evaporation exceeds the supply of water by precipitation) lead to more frequent low water levels. This increases the risk of dehydration or eutrophication, i.e. an excessive inflow of nutrients into the water and thus resulting oxygen shortages, especially for smaller standing waters.

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Adaptation to Climate Change

Technical measures

Nature responds to changes in climatic conditions: It adapts itself. However, this process is frequently impeded by the human way of life and the economy. If this is the case, dynamic spatial and temporal adaptation processes are often only possible to a limited extent.

For that reason, humans should support the naturally existing dynamics and the adaptation potential of nature by preserving and promoting the functionality of ecosystems. To preserve those animal and plant species that are bound to specific location and habitat conditions, they have to be given the opportunity to move to whatever habitat is most suitable for each of them. Thus, a large-scale assessment of protected areas beyond their boundaries is important to identify potential interlinked systems of biotopes. These requirements are necessary for the preservation of biodiversity.

Technical solutions play an important role for such interlinked habitat systems. Many species need such a system because it is a crucial prerequisite for adaptation to climate change. In practice, interlinking habitats requires corridor areas, lead structures such as hedges and stepping stone habitats, migration corridors and green bridges. These are crucial elements and are specifically geared to the respectively supported species. At the same time, technical measures can reduce the barrier effect of roads, waterway constructions and intensively used areas. The diversity of habitat structures in the landscape further supports the linking of biotopes.

Ecosystem Measures

The creation of an effective system of interlinked biotopes, which is also an objective of Natura 2000, is probably one of the most important measures in the area of “green infrastructure”. According to the Nature Conservation Act (Federal Nature Conservation Act § 4), the federal states have to make at least 10 percent of their land area available for habitat network purposes. A large-scale examination is thus important.

The purpose of interlinking habitats is to enable migration to and distribution of species in future habitats. Species affected by climate change can only find new suitable habitats through these territorial connections. For that reason, an effective habitat network shall be developed and implemented across the federal states. The fragmentation of natural systems and land use must be reduced, and sectoral planning – for example concerning settlements, infrastructure or transport – has to be adapted accordingly.
Other “green” measures involve the installation and maintenance of near-natural green spaces in cities and alternate habitats. Another measure is the process protection as a nature conservation strategy that is based on the non-interference with natural processes of ecosystems.

Furthermore, the protection of wetland habitats such as swamps and water meadows is an important measure, which at the same time contributes to climate protection. Targeted stabilisation and improvement of the water balance, restoration, rewetting, nature-friendly alternative types of use and other measures shall protect the particularly climate-sensitive habitats not only in protected areas, but already in their catchment areas.

In agriculture, there are further possible measures that contribute to nature conservation. Careful soil cultivation, the protection of the biological diversity of agriculture and a reduction of stress factors are meant to improve the synergy between agriculture, nature conservation, soil conservation, water conservation and climate protection. In that respect, organic farming constitutes an extremely environmentally friendly alternative to conventional agriculture.

Legal, political and management measures

Policies at the federal and state level but also the international level have to ensure that suitable framework conditions for the dynamic adaptation of nature conservation are established. For this purpose, the concept of nature conservation needs to be refined with regard to climate change. The aim is to align nature conservation so as to ensure that as many functional ecosystems as possible are maintained to provide a maximum number of species with intact habitats. The focus on small-scale protected areas should be reconsidered. Also flexible habitat boundaries can be an effective solution in view of migrating species.

Special precautionary measures are necessary for those species whose future habitats have no overlaps with their current distribution areas. In addition, species that are only capable of migrating to a limited degree require special protection. In their case, targeted measures introducing them to new habitats are worth considering.

The development of the system of protected areas must take into account climate change requirements. In that context, the EU’s network of protected areas “Natura 2000” is already making an important contribution to the interlinking of protected areas and thus to the reduction of negative impacts of climate change. Furthermore, also the competent state and nature conservation authorities can take the changing climatic conditions into account when compiling maintenance and development plans and management plans for protected areas. In that regard, adaptive management, which allows for a dynamic management of protected areas, is an important tool. Protection objectives can be re-evaluated and adapted to changing conditions.

Also the monitoring of climate impacts on biodiversity plays an important role. The conservation of biological diversity requires transnational cooperation and a timely exchange of information. Against this background, a monitoring system for climate impacts and already initiated measures and the precise definition of target criteria is of crucial importance, too. Monitoring and early warning systems are also useful in order to support particularly affected species and habitats as well as for dealing with invasive species. Based on their results, risk assessments can be carried out and recommendations can be made. This is the only way to ensure that climate-related hazards and new requirements are addressed specifically and efficiently.

If you are interested in obtaining information about concrete impacts of climate change in the field of action biological diversity, please click here.