In the context of rapid changes in the contemporary world, protecting and improving the natural environment is essential. Biodiversity represents the variety of life on Earth, it has a fundamental role in maintaining the ecological balance. This influences everyday aspects such as food, materials, energy, infrastructure, while ensuring access to vital resources such as clean air, water and productive ecosystems. The scientific community has sounded the alarm about the critical state of global biodiversity: nearly a million species are in imminent danger of extinction, natural areas and ecosystems are rapidly diminishing.
For example, in the UK, the decline in biodiversity is alarming, averaging 19% since 1970, which poses significant risks, with one in six species at risk of extinction. Biodiversity loss is highlighted in the State of Nature 2023 report, even as the government has pledged to improve the environment. This trend not only threatens the productivity of ecosystems, but can also lead to the deterioration of their functionality, with negative effects on human well-being. In the situation where ecosystems reach a critical point of decline, they could suffer significant restrictions, leading to the emergence of entirely new ecosystems with unknown functionalities. Climate change, along with invasive species and disease, are considered significant factors in biodiversity decline, and projections indicate an increase in their importance in the future.
To maintain ecological balance, global biodiversity should preferably remain above a safe threshold of 90%, but estimates up to 2021 point to just 75%, underscoring the need for urgent action to prevent an ecological recession.
Since 2011, the UK government has launched six biodiversity offset pilot projects in England, assessing and monitoring their feasibility and implementation, resulting in the mandatory introduction of the Biodiversity Net Gain in February 2023. This ensures that development not only minimizes impacts on the environment, but actively contributes to its improvement. The initiative offers developers a distinct opportunity to offset the environmental degradation caused by their projects by implementing nature-based solutions, thereby addressing both climate and biodiversity crises (based on the principle of keeping the environment in a more favorable state than before implementation).
Ecosystem services provided by urban biodiversity
In a time when access to nature is increasingly limited, especially in cities, the importance of green areas is more and more evident. In the context of rapidly increasing urbanization, these spaces are essential not only for our well-being, but also for the health of the planet. Adding biodiversity to gardens and urban environments is crucial to implementing sustainable and vibrant environments. We must focus on developing solutions inspired by nature that not only increase biodiversity, but also facilitate the connection between people and the environment, promote positive visual and emotional experiences.
Social acceptance is particularly important for the long-term success of green areas rich in biodiversity, therefore meadows with thousands of flowers must be accessible and attractive to all, it is also essential to educate and inform society to recognize the ecological importance of these areas.
Understanding the critical importance of biodiversity is the first priority, it is not just a feature of nature but essential to our daily lives. It directly and indirectly influences many aspects of human existence:
Climate change mitigation
Destruction of forests, tundras and oceans releases greenhouse gases, accelerating global warming; and the built environment contributes at least 20% to climate change. Biodiverse plants absorb carbon and act as barriers against extreme weather, cooling the air temperature. Efforts by the UN, EU and scientists aim to protect at least 30% of ecosystems. Integrated solutions focusing on climate and biodiversity are being developed.
Food security
Our reliance on agricultural crops makes our food system vulnerable to extreme weather, diseases. Moreover, the growth of crops is determined by the activity of pollinators. Conserving and enhancing biodiversity is crucial for resilience against climate change and for maintaining pollinators by providing refuges and food sources.
Clean air and water
Biodiversity supports essential ecosystem services such as oxygen production and water purification. Greater biodiversity ensures the conservation of these services for our survival. Due to the high water retention capacity, biodiverse surfaces actively contribute to the facilitation of the urban sewage system, which is essential in case of torrential rains.
Disease and pest prevention
The interdependence of species maintains balance in ecosystems, preventing pests and disease outbreaks. Genetic biodiversity reduces vulnerability and maintains ecological balance in urban ecosystems.
Life quality
Nature and biodiversity improve health, well-being and quality of life. Natural areas contribute to positive interactions and promote the natural beauty of landscapes through the richness of species, shapes and colors.
Financial savings
On the other hand, the inclusion of areas with biodiverse meadows in the urban environment presents a significant economic advantage, compared to complex landscaping, because it brings with it a financial saving, and of natural resources, such as water or electricity. The maintenance costs of complex green spaces are significantly higher than those of biodiverse urban grasslands, implying additional resources for their management. The general trend of increasing prices indicates a common challenge for local governments in maintaining and caring for green spaces in a sustainable and financially efficient way. In Romania, in recent years, the costs of maintaining green areas have increased significantly, generating much higher costs for local authorities. In 2015 alone, the price increase was 75% compared to 2010 prices, and in some cities it even reached 1050%. Currently, these values have reached exceptional proportions, imposing a significant financial burden on local authorities for the maintenance of green areas (e.g. with an annual budget of over 800,000,000 Euros in Bucharest).Monthly maintenance of parks and urban green areas generally involves the following activities: mowing and trimming hedges, shaping shrubs and trees, regular irrigation, fertilizing and necessary treatments, managing plant growth, removing weeds and plant debris, overseeding the lawn, preparing surfaces depending on the season.For example, if we consider an area of 3 hectares of green area, the estimated costs would be as follows: Weed control – 6000 Euros (0.2 Eur/m2), hedge cutting (calculated for an average of 800 m) 2,400 Euros (3 Euros/m), tree shaping (calculated with 500 trees on average, proportioned on a surface of 3 ha): between 3000 and 60,000 Euros (price/piece varies between 6 and 100 Euros, depending on the size of the tree), lawn scarification 15,000 Euros (0.5 Euros/m2), lawn aeration 75,000 Euros (2,5 Euros/m2), overseeding the lawn 48,000 eur (1.6 Euros/m2), mowing the lawn 15,000 Euros (0.5 Euros/m2). The monthly maintenance costs for a green area of 3 ha can reach an amount of 190,000 Euros, depending on the complexity of the arrangement and the interventions required for proper maintenance.On the other hand, biodiverse carpets, similar to meadows with thousands of flowers, have minimal maintenance needs; thanks to the choice of resistant species, it develops well even without irrigation systems; thanks to the biological diversity, the plants are resistant to diseases and pests, as a result, the need for fertilization and treatments is reduced; also, due to the multitude of resistant indigenous species, the chance of alien species and unwanted weeds is minimized. Also, mowing the biodiverse blanket is recommended to be done only once a year, to protect the local flora and fauna. Maintenance costs, in this sense are minimized, and are considerably lower than complex green spaces, costing approximately 0.3 Euros/m2 + VAT annually, which includes manual mowing once a year, subsequent removal of vegetation and surface treatment with fertilizers.The advantages of biodiverse plantations over grassy areas
Urban green spaces provide vital ecological, environmental and cultural benefits, including biodiversity conservation and human well-being. However, a substantial portion is maintained as uniform grass, providing lower ecosystem benefits. The transition to diverse grasslands could bring many advantages, including improved biodiversity, better stormwater management and aesthetics. However, understanding of ecosystem services and trade-offs between grass and grassland management in urban green spaces is limited.
Well-managed vegetated areas, mainly lawns dominated by perennial grass species, cover a significant part of urban green spaces globally. In the United States, grasses occupy about 1.9% of the land area, while in Sweden they cover 0.6% of the land. Globally, grasses represent about 1.4% of the total land area. However, there is a recent shift in urban greenspace management towards supporting diverse native grasslands to improve ecosystem services such as biodiversity conservation, environmental sustainability and aesthetic values, while reducing costs associated with grass management.
Grasses are becoming more prevalent in urban landscapes around the world, driven by accelerated urbanization and the desire to adopt Western culture. Studies project a significant increase in grass area, an estimated 79% increase by 2030. Grasses play a crucial role in urban planning and management, providing various ecosystem benefits such as visual aesthetics, health benefits, urban temperature regulation, flood control and pollution, soil stability, erosion control, landscape visibility and carbon storage. However, lawn maintenance with irrigation, mowing and fertilization can increase greenhouse gas emissions. Grass maintenance practices require intensive management, therefore raising concerns about financial costs, loss of biodiversity, environmental pollution and contributions to global warming. These ecological impacts determine the need to re-evaluate the management of urban green spaces. In recent years, there has been a growing recognition among conservationists, urban planners, landscapers, park visitors and the general public of the benefits of adopting more natural, sustainable and cost-effective approaches to managing urban green spaces. This includes the creation of diverse ecosystem services through the implementation of natural grasslands, using locally adapted plant species, which provide additional benefits beyond recreation, sports and aesthetics.
