What is an ecosystem? An ecosystem is the set of living organisms present in a certain area and the non-living elements with which they interact. For example, a lake is an ecosystem composed of the aquatic animals, plants and microorganisms that inhabit it, the fresh water that is the basis of their sustenance, the bottom of the lake on which some plants grow, and the rocks where fish lay their eggs. What does it contain? An ecosystem consists of: living components (collectively known as biota), namely plants, animals, fungi and microorganisms; non-living or abiotic components (both organic and inorganic) such as soil, rocks, and sand, to which atmospheric agents (e.g., wind and rain) must be added. Living organisms are in turn divided into three categories: autotrophs (green plants and some bacteria), which can synthesize organic substances from inorganic matter; consumers (animals and some plants), which feed on other organisms or the organic substances they produce; decomposers (bacteria, fungi and others), which cause organic molecules to decompose by producing substances used by producers, thus restarting the cycle. Within an ecosystem each species has its own habitat, in other words, an area whose characteristics enable it fulfill its life cycle. In general, therefore, an ecosystem consists of several habitats that partly overlap with one another. It isn’t only the elements that make up an ecosystem that are important, but also, and above all, the relationships that bind them: they all depend on each other, either directly or indirectly. Furthermore, an ecosystem is an open system. In other words, there are exchanges of materials and energy with other ecosystems: for example, when animals move around, or when the wind carries pollen and other substances, both organic and inorganic. Types of ecosystem Ecosystems are often classified into macrocategories, each of which, however, includes ecosystems that differ widely in terms of climate, flora and fauna. Forests: rain forests (such as the Amazon), tropical dry forests (Colombia), taiga (vast lowland forests such as those in Canada or Finland) and Mediterranean scrub. Grasslands: include large prairies (e.g., the Great Plains in North America) and pastures, but less lush areas, such as savannas (in much of Africa and Australia) and steppes (Central Asia), also fall into this category. Deserts: hot deserts (such as the Sahara), cold deserts (the Gobi) and frozen deserts (Antarctica, Greenland). Tundra: cold subpolar areas with low vegetation (Siberia, Alaska, Iceland, etc.). Mountainous ecosystems (the Himalayas, the Andes, the Alps, etc.). Marine ecosystems: seas, oceans, salt lakes, coral reefs and brackish areas. Freshwater ecosystems: lakes, rivers, swamps and ponds. Biodiversity in ecosystems Each ecosystem is distinguished by its biodiversity, i.e., the variety of life forms it hosts and the relationships between them. The main parameters by which it is measured are the number of species present and their variety. Other biodiversity indices include genetic diversity, i.e., genetic variety within the same species, and the distribution of species in the various habitats of the ecosystem. Biodiversity indices are in turn interrelated: the more numerous and diverse the species present, the more varied their habitats and the greater their possible configurations within the ecosystem. The balanced ecosystem An ecosystem is balanced if its composition and relational structure remain unchanged (and thus its biodiversity remains constant) Equilibrium does not mean stagnation; on the contrary, in an ecosystem the elements are constantly changing: individuals are born and die and in the meantime grow, reproduce and often – in the case of animals and microorganisms – move, even from one habitat to another. The equilibrium of an ecosystem can be more or less stable depending on its resilience, i.e., its ability to return to its initial state following a disturbance: an ecosystem that is resilient, i.e., in stable equilibrium, is one that is able to re-establish itself by re-colonizing a portion of it that has been damaged by, for example, a fire, landslide or storm surge. If, on the other hand, an ecosystem is not very resilient, that is, if a disturbance damages it irreparably, it is referred to as an unstable equilibrium. One factor in the balance is the food chain. If a species with a specific role disappears in an ecosystem, there is a risk of imbalance: if, for example, a carnivore disappears, it is likely that the herbivore species on which it was feeding will overproliferate, with a knock-on imbalance even on the plants that provide the basis of its diet. The greater the biodiversity of an ecosystem, the greater its resilience (and thus its stability): for example, if there are many species of pollinating insects in a forest, even the disappearance of one of them will not affect the cycle of flowering plants and thus the health of the ecosystem. This is just one of many possible examples, but it is particularly indicative, given the crucial role of pollinator species in agriculture: it shows the importance of ecosystem biodiversity, not only for nature conservation but also for human activity. Endangered ecosystems Today all ecosystems on our planet are threatened by human activity. The greatest danger, especially in the medium and long term, comes from climate change. The increase in average temperatures is in itself a factor that alters the balance of an ecosystem by affecting the distribution of vegetation and thus the entire food chain. Furthermore, many ecosystems are threatened by desertification and rising sea levels caused by melting glaciers. Climate change is the result of emissions caused by human activity, especially industrial activity, which also affects ecosystems directly: air pollution affects the health of living organisms and thus, on a large scale, the health of the ecosystems in which they live. Certain ecosystems are then threatened by specific human activities. In particular, the deforestation of vast areas, especially in the tropical belts, is reducing the size of some of the world's most biodiversity-rich ecosystems. Intensive fishing (or overfishing), on the other hand, severely affects the biodiversity of aquatic ecosystems, especially ocean ecosystems, thereby altering their balance. The human role in preserving the natural environment Humanity, which is putting ecosystems at risk, also has the tools to preserve them. The most effective solution for mitigating climate change is reducing greenhouse gas emissions. This requires completing the transition to an energy system based on renewable sources and, at the same time, switching to electricity in areas such as transportation and heating. These are all measures that can also help limit air pollution. In the immediate term, there’s an urgent need to reduce activities such as intensive fishing, and to stop deforestation. Our Group is therefore committed to conserving current forest sizes with reforestation works in line with the principle of "No net Deforestation." At the same time, it is necessary to act with local-level measures aimed at preserving ecosystems that are still intact and repopulating those that have already been altered or are likely to be compromised. Several international commitments, including the 2030 European Biodiversity Strategy, are designed to bring this about. As part of our biodiversity strategy, we have initiated numerous projects for restoring ecosystems in several European (Italy, Spain and Greece) and American (Chile, Colombia, Brazil and the United States) countries. One of the most impressive projects is the restoration of the Colombian tropical dry forest, a rare and valuable ecosystem. We have begun to restore an area of more than 7,000 hectares. We have also launched an important project in Brazil, in the state of Rio Grande do Sul. This is for the reforestation of indigenous lands in order to preserve ecosystems in protected areas. We have set up a similar initiative for reforestation with native species for the benefit of indigenous peoples in Chile. Regarding aquatic ecosystems, we have repopulated the Rio Magdalena in Colombia with nearly three million fish from native species, while in Italy we have dedicated a project to the protection of several endemic species in the Ticino River basin. In Minnesota (in the USA) we have initiated the restoration of habitats favorable to pollinator species, while in Catalonia (Spain) we have restored habitats that were at risk: we are promoting brown bear conservation in the Pyrenees Natural Park with integrated solutions including the planting of nearly 10,000 fruit trees. These are just a few examples of a long series of wide-ranging activities that we carry out in the countries where we operate. They are outlined in our 2022 Sustainability Report, specifically in the chapter on natural capital conservation.
