Biodiversity is not limited to all the species living in a given location, but also includes all the interactions between species. To understand the very basis of life on Earth, it is essential to understand these relationships that form a complex, fragile balance.
What is an ecosystem?
An ecosystem is a dynamic system of plants, animals, fungi and micro-organisms and their environment: water, air, earth and temperature. This system creates a particular way of life in a given place. Both the living and non-living components of an ecosystem play a specific role. The ecosystem is composed of a biotope (a given environment with specific physical and chemical characteristics) and a community (all the organisms that live there).
An ecosystem can be any size or form. It may comprise a small space such as a pond or anthill, or a much bigger area such as a desert or a sea. Even our intestinal flora is an ecosystem in its own right.
What are the threats to this balance?
The presence of commodities such as pure water, oxygen, food and fuels seems so ‘natural’ that we forget their origin. It is difficult to imagine that humans could destroy such fundamental services, but many ecosystems (and therefore the services they provide) are under serious threat.
Actions with a limited local impact may cause chain reactions that have serious consequences for an entire ecosystem. There are so many and such diverse threats that ecosystems are no longer able to restore their natural balance.
Climate change is often front page news, and this media attention is fully justified. The current problem stems from the fact that human activities – mainly the burning of fossil fuels to meet our ever-growing energy needs – have released huge amounts of greenhouse gases into the atmosphere since the start of the industrial revolution. These emissions significantly increase the natural greenhouse effect, resulting in progressive global warming.
The warming of the oceans, the changing frequency and intensity of rainfall, the change in storm activity, the reduction in ice and snow and the increasing level and acidification of the oceans are all phenomena linked to global warming. And they all have an impact on biodiversity!
My2050 is an interactive, educational web tool that allows us to create tomorrow’s society by choosing scenarios that reduce our CO2 production.
Global warming is forcing indigenous species to adapt or die. They may also be forced to move away, as new species move in and develop, sometimes extensively and at the expense of local species.
Rising temperatures means that certain spring occurrences, such as the flowering of buds, are happening earlier (5 to 15 days earlier than 50 years ago), and some autumn occurrences later, such as the yellowing of leaves. These changes are devastating inter-species interactions.
Grolar (or pizzly) is not an insult but a grizzly-polar bear hybrid. This phenomenon is still rare, but could become more common as a result of climate change. The melting of the ice sheets is forcing polar bears towards southern Canada and grizzly bears are moving towards the northern forests. Both species are forced to live in the same area for part of the year. What’s more, the melting of the ice sheets is causing a drop in the polar bear population. This drop reduces the possibility of a male and a female of the same species meeting and reproducing, leading them to reproduce with a similar species such as the grizzly bear.
In Belgium, we are already observing an increase in the presence and number of species from warm, temperate climates. These include southern dragonflies (scarlet dragonfly), spiders (wasp spider originally from the Mediterranean Basin), birds (European bee-eater, a southern species that now nests in Belgium) and mosquitoes (carriers of tropical diseases such as West Nile Virus). Certain harmful species, such as ticks and army-worms, are multiplying due to climate change. More southerly species such as sardines and anchovies are arriving in the North Sea following the rise in water temperatures. Indigenous species such as shrimps are migrating to colder waters.
Alien invasive species
An invasive alien species is a living organism (animal or plant) that has been introduced by humans, either intentionally or unintentionally, outside its natural place of existence. The term “alien” is used in contrast with “indigenous” species, which are species naturally found in a region. The species is called “invasive” because it adapts to its new environment, causing significant damage to the natural biodiversity and habitats.
Alien invasive species
Alien species have been introduced into Europe and elsewhere in the world since time immemorial. But they are not all invasive, either because they pose no risk to the ecosystem or because they cannot adapt and thus reproduce.
But the threat to the environment is now greater than ever, due to the significant increase in trade exchanges and the great demand for alien plants and animals. The introduction of these alien species sometimes causes problems for the health of human and/or animal species.
At the European level, alien invasive species represent an estimated economic loss of 12 billion euros.
A global problem
The problem of alien invasive species is a global one. It is considered to be the second largest cause of biodiversity loss in the world, after the disappearance of natural habitats.
The Belgian federal authorities are taking action to combat invasive species.
A small tortoise that has become big
Many exotic species are sold in pet shops to satisfy our passion for specific pets. The small tortoises of Florida are a typical example. Unfortunately, they are considerably less agreeable once they have aged and become so big that they can no longer be kept in an aquarium. They are often released back into nature, and can currently be found in many ponds and lakes and even in some nature reserves. The Florida tortoise poses a threat to aquatic biodiversity, as it feeds on plants, dragonfly larva, frogs, newts, small fish, etc. It competes with other species. What’s more, its strong beak can inflict painful bites.
Biodiversity is a source of food and raw materials for more than seven billion human beings. Unfortunately, most of the ecosystems that provide these services are not exploited sustainably. The main examples of overexploitation are overfishing, excessive hunting of wild animals, excessive cutting down of firewood and the depletion of agricultural land.
The resulting ecological consequences are unpredictable. But one thing is certain, namely that the time will come when the ecosystem will no longer be able to restore its natural balance and some species will become increasingly rare or disappear.
One striking example of overexploitation is the illegal trafficking of ivory
In figures: 36,000 elephants are killed every year, i.e. 100 a day, four an hour, one every fifteen minutes.
On 9 April 2014, Belgium destroyed the illegal ivory seized by its Customs services to send a strong signal to traffickers and poachers.
The trafficking of endangered species: the example of the pangolin
The situation is not much better for pangolins, as the mammal’s scales are very popular in traditional Chinese medicine. Two or three animals have to be killed to obtain a kilo of scales and as a result, pangolins are now threatened with extinction. At the end of 2016, they received the highest level of protection granted by the CITES Convention and can no longer be captured in nature. But poaching is having a devastating effect.
The destruction and fragmentation of habitats
If a habitat or biotope is destroyed, the ecosystem that lives there will inevitably die out for good. As well as its total disappearance, the fragmentation of habitats also harms ecosystems and the community it houses. Not only do species have less food and fewer nesting sites available, the distance to other suitable habitats also increases. The populations living there are sparse and are now much more susceptible to unforeseen circumstances, such as drought, floods and diseases. It is primarily species with little ability to disperse or those which need a vast habitat that pay the higher price.
The orangutan: an ape threatened by deforestation
This large ape, with which we share approximately 98% of our genetic heritage, lives only in the Indonesian islands of Borneo and Sumatra. Its population has dropped from several hundred thousand individuals to approximately 65,000 in 120 years. The orangutan could have completely disappeared from its natural habitat within 20 years if deforestation, carried out mainly for the production of palm oil, continues at its current rate. The preservation of this biotope is absolutely vital for the orangutan (“man of the forest” in Malay), which feeds, reproduces, sleeps and moves around within these trees.
One way to prevent this threat is to create sanctuaries where human action is regulated or even banned.
The largest sanctuary in the world is in the Antarctic, which is protected by an international treaty. Belgium is one of the countries which allowed the existence of this Treaty.
There are many examples of the negative effects of pollution on the functioning of ecosystems and the life of the species that composes them. Pollution can take several forms: solid (everyday waste), liquid (pesticides, oil, fertiliser, etc.) or gas (exhaust pipes, factory fumes, etc.). The negative impact varies depending on the environment being contaminated: the rivers and the increased scarcity of some fish, soils and the disappearance of the insects required to form them and keep them stable, the ocean and the dangers of plastics for marine animals, etc. They all represent threats to biodiversity and are not without risk to human health! Pollutants can actually enter our food chain. But pollution is not limited to these “palpable” pollutants. There are other forms of pollution with harmful or even disastrous effects on biodiversity. One example of this is noise pollution, which affects the animal behaviour and directly threatens their survival.
All kinds of plastic waste are thrown into the sea every day around the world: bottles, bags, bits of net, etc. This waste is carried by the currents and forms huge clusters, veritable floating islands just under the surface of the sea. This residue is known as plastic soup and is dangerous or even fatal for marine animals, particularly in the case of large waste such as bags and bits of net. Fish, birds and marine mammals get caught in this waste and drown. Every year, porpoises are found stranded on our coast having been caught up in the nets used by amateur fishermen. Marine animals can also die after swallowing floating waste.
Noise pollution and collisions:
mortal dangers for whales and dolphins
The seas and oceans are the scene of a growing number of activities, such as sailing, fishing, energy production, military operations, sports and leisure. This means that international maritime traffic has significantly increased over the last decade. Ships are getting bigger, faster and noisier. Cetaceans, which have particularly acute hearing that helps them to communicate, find their bearings, feed and measure distances, can no longer correctly assess threats. Whales and dolphins are the main victims of noise pollution in the sea. But another equally mortal danger awaits them: collision with ships. Reducing noise pollution in the sea and the risks of collision has become essential for the survival of these marine mammals.