The city dwellers have a smaller ecological footprint, yet as the cities grow, we must also preserve and maintain biological diversity in urban areas, which, among other things, also helps to ensure the high living standard for its residents.
Urban nature for nature
The facts and figures which I present at the outset of my article appear to suggest a rather bleak outlook for future, but I promise to steer clear of doom mongering and focus on offering various solutions to remedy the situation instead. Still, in order to develop new perspectives on urban nature, a brief introduction into the current state of affairs is necessary. A mere hundred years ago, a third of Estonia’s territory (1.8 million hectares) was covered by grassland communities.1 Wooded meadows which, due to their mixed character, are suitable habitats for both grassland and forest species spread on over 850,000 hectares in Estonia, then being one of the most common habitat types everywhere around the Baltic Sea (Kukk and Kull 1997). By now, grassland communities have almost vanished both in Estonia and Europe. In Estonia, ca 60 000 ha remain, which amounts to less than 5% of what existed in the early 20th century. If grasslands disappear, so will the species who live there, including such iconic and/or ecologically crucial plant, invertebrate and animal groups as meadow flowers, bumblebees, butterflies, grassland birds, etc. These do not live on lawns, rape fields or parking lots, not even roadsides or fallow fields, as these habitats cannot offer them what they need. Due to an extensive transformation of landscapes in Europe, the populations of grassland bird species have dropped by half since 1980s and the number of butterflies has been reduced by 45% since 1990. From Germany, a message was received in autumn 2017 that within the span of 27 years, the country’s nature conservation areas have lost more than 75% of their flying insects (Hallmann et al. 2017). The current landscapes, intensive forestry and loss of wooded meadows also affect adversely many forest species, thus the Estonian forests have been losing each year 60,000 pairs of forest birds and, compared to 1980, the number of birds in Estonian forests has dropped by a quarter. (Estonian Ornithological Society 2017).
In the light of such depressing figures, it is imperative that we rethink our approach to nature conservation and wildlife protection. The land use today is danger to the preservation of many species and existing nature conservation areas do not seem to be enough to stop their disappearance. What can we do? Let us turn our attention to cities.
On a larger scale, such as countries, the urban centres and the ‘hot spots’ of biodiversity frequently coincide―the cities are often founded in naturally diverse locations. As a broad generalisation, we can even say that we have created settlements in those very spots where we should protect the nature. The expansion of urban areas has a negative effect on biodiversity, mainly due to the destruction, fragmentation and shrinking of existing habitats. Therefore, we should take the preservation and maintenance of natural biodiversity in cities and their immediate neighbourhood very seriously. In the future, the fate of many species may precisely depend on how successful we will be in preserving and nurturing the rich animal and plant life in our cities and suburbs.
Urban nature for humans
Rich urban plant life and emphasis on natural environment helps to reduce the ecological footprint of urbanisation, but even if nature conservation is not very high on our agenda, the condition of our living environment is inextricably linked to our mental and physical health and is a source of aesthetic enjoyment, not to mention other important benefits which the urban nature can offer―flood regulation, maintenance of water quality, reduction of noise and UV radiation, decreased urban heat island effect, natural cooling or heating opportunities which can be used to save energy, etc. During the last decade, more and more scientific evidence has been gathered to lead us to the conclusion that humans are meant to live in biodiverse environments. The biodiversity of the surrounding environment is associated with better physical and mental health, longer lifespan, cognitive well-being and stronger sense of identity (Lovasi et al. 2008). For example, the respondents to a survey conducted in Italian cities regarded the biodiverse and plant-rich urban greeneries, when compared to more species-poor areas as having a greater impact on their perceived restorativeness and self-reported well-being benefits. Another interesting finding is that the environmental biodiversity in one’s surroundings influences the composition of bacterial classes on one’s skin and reduces the occurrence of allergy. (Hanski et al. 2012). It has also been found that urban neighbourhood greenspace is associated with the longer lifespan of city dwellers (Tzoulas et al. 2007).
Of course, urban nature can have certain negative effects as well―wind-pollinated species cause problems for people suffering from allergy, trees can damage pavement and road surface through root heave, be a danger for buildings and block sunlight, urban foxes may transmit diseases to domestic animals and pets. Perceptions of urban nature are also shaped by the people’s preferences and attitudes―many find birds and insects unpleasant and frightening, the parks can appear dark and menacing after sunset, and some people simply do not take well to any changes in what they have become used to see in their city. Thus, the short-mown grass of perfect lawns has become the norm of the modern day and, in a recent survey conducted in Tartu, many respondents subscribed to the view that naturally high-growing grasses in parks would leave an impression of poor maintenance and lack of order (Vaaks 2017). However, the benefits which urban nature can offer offset many times over the potential problems which can be avoided by competent city planning, awareness raising and ecological landscaping.
In addition to furthering nature conservation goals and improving our living conditions in the cities, urban nature can also translate into direct financial gain: in Barcelona, the contribution of the existing urban nature in improving the quality of the city air was estimated (using the avoided cost method) to equal the amount of 1.1m euros per year, in the city of Sacramento in the United States, the same figure was estimated at 1,500 dollars per hectare in the city, totalling 28.7 million dollars in a year.
In addition to preserving the quality of air, each tree in a city provides a ‘thermal regulation’ service with the estimated worth of 10-15 dollars per year (Gómez-Baggethun & Barton 2013). Thus, the future urban greenery and city planning must make rapid strides towards the maximisation of the two-fold purpose of urban nature―nature conservation and improvement of living environment. In order to secure the biodiversity in our environment and thereby the human well-being, we must progress towards a more thought-out environment in city planning and ensure the preservation of natural communities and rich greenery that promotes biodiversity.
City built of natural communities
Which solutions are helpful for natural environment and humans, what to avoid at all costs and what can we ourselves in our cities do to help? The first priority is the economically sustainable management and development of the existing urban nature. ‘Blandscaping’, a recent buzzword, denotes landscaping and urban greening that unfailingly applies the same standard solutions derived from the current landscaping trends and habits, yet by doing so ignores and destroys the natural environment and ecological assets that are unique to the particular area (Connop & Nash 2018). These fashionable yet uniform landscaping designs which consistently stick to the same species and styles in fact make our natural environment poorer. Luckily, there are signs which indicate a culture change taking place in landscaping which, up to present, has mostly been doing ‘blandscaping’ and an understanding is emerging that a knowledge of ecology or ecology-based expert advice are integral to creating a multifunctional and high-quality urban space. Historical species-rich grassland communities whose value would be immense from the standpoint of nature conservation remain to a degree in almost every Estonian city or its immediate neighbourhood. The restoration and maintenance of meadows and their integration in the city space would save species and enhance the living environment of city dwellers.
A good example is the restoration of Pärnu coastal meadow, previously overgrown by bushes and reed, now used as a pasture for grazing animals and open for visitation by city folk, accomplished as part of the project ‘Urban Cows’. The initial fears of the city residents regarding the transformation of the landscape were replaced by positive perceptions of the results achieved. By now, Pärnu can be regarded as the early bird showing the way for other cities―the lawn maintenance on Viljandi’s castle hills was taken over by a herd of sheep in the previous year, demonstrating a perfect combination of restoration of heritage communities and promotion of biodiversity, environmental education and diversity-promoting city planning. The city of Kuressaare is currently restoring the rare alvar pastures remaining within the city limits, making room in these overgrown ecosystems for flowers, butterflies and people once again. Potential for such commendable activities in Estonian cities, however, remains plenty. Within Tallinn’s city limits, many historical grassland communities exist which should be integrated into the city’s greening projects. Raadi nature reserve which straddles the city border of Tartu contains an extremely valuable but completely forgotten grassland community whose restoration and maintenance would give us, in addition to fostering biodiversity, a valuable recreation site for city residents and a hotspot for environmental education at the same time.
What else? An increasingly acute problem is posed by the direct covering of the ground surface or non-permeable paving which, quite permanently, deprives us from all benefits of natural environment. Urban greening should strive for the reduction of paved ground or ‘hardscapes’ and, while erecting buildings, the loss of natural ground surface should be compensated by the creation of green roofs or vertical gardens. Green roofs can be important urban hotbeds for plant and animal life if they are set to host species-rich communities of (NB!) native plants and other similar roofs can be found in the neighbourhood, i.e., the landscape connectivity of habitats is ensured. Such an interconnected system of green roofs can also offer shelter and sustenance to insects and birds and the species-rich plant community endures. The property maintenance rules of a number of Estonian cities currently require personal vehicles to be parked on the residential lots of their owners, which in turn has necessitated the paving of much of the ground surface in people’s home yards. This is not a sustainable solution―stone pavement completely blocks the outside access to soil and deprives species of their habitat and puts an additional burden on sewerage systems, as the yards’ ability to absorb rainwater is compromised.
The design of urban greeneries could rely more on natural plant growth and less on the endless expanses of flat lawn surfaces. Each city could take pride in landscape solutions which skilfully integrate the people’s recreation areas with diverse plant life.
The small planting beds of urban gardens where the city dwellers grow a multitude of different crops side by side are, according to a study conducted in England, the most biodiverse hotspots in the entire city, supporting rich life from soil bacteria and fungi to butterflies and other insects. This finding definitely calls for effective incentives to be put in place to promote the creation of further urban gardens, including public ones.
The management of plant life in private gardens, especially in large suburbs, plays a crucial role for the protection of biodiversity. If everyone leaved a greater portion of their garden to natural plant growth and made hay once a year, as a hobby and physical exercise, a small but important personal contribution to the preservation of grassland communities would be made. In terms of biodiversity, a well-mowed lawn is almost just as good as an asphalted parking lot. The 15cm maximum height requirement for grass growing on residential lots and greeneries, currently included in the property maintenance rules of a number of Estonian cities, should definitely be abolished.
Urban nature actually does not need that much at all―just a change in our way of thinking and city planning which needs to make the considerations of nature conservation its priority. If urban nature is thriving, we can be sure that life is sustainable both for us and, we can hope, for a multitude of other species.
Measures which promote urban biodiversity:
- Avoidance of ‘blandscaping’.
- Preservation of existing natural assets (communities, species) and improvement of their condition.
- Avoidance of hardscaping, creation of vertical gardens and green roofs hosting communities of native plant species.
- Structurally diverse and multifunctional greeneries supporting natural plant life.
- Everyone’s nature conservation―promote and support natural diversity in your home yard as your personal contribution to nature conservation. Our small personal acts can make a difference in the preservation of biodiversity and creation of a more varied urban space. Mow your lawn less frequently, let the wilderness take over the back corner of your garden, steer clear of pesticides, leave a few piles of fallen leaves for the hedgehogs to spend their winter in, build a nest box for birds and an ‘insect hotel’ for insects, and a million other little things.
AVELIINA HELM holds the position of Senior Research Fellow in Botany at the University of Tartu and focuses on the matters of biodiversity in her research. Her university spin-off company Nordic Botanical offers botany and ecology-related advice for creating more natural greeneries and also produces seeds of meadow plants.
HEADER photo by Mati Kose.
PUBLISHED in Maja’s 2018 spring edition (no 93).
Connop, S. & Nash, C. 2018. Blandscaping that erases local ecological diversity. The Nature of Cities. https://www.thenatureofcities.com/2018/01/09/blandscaping-erases-local-ecological-diversity/
Eesti Ornitoloogiaühing. 2017. Eesti metsadest on kadunud 60 000 linnupaari aastas. https://www.eoy.ee/rasvatihane/uudised/eesti-metsadest-on-kadunud-60-000-linnupaari-aastas.
Gómez-Baggethun, E., & Barton, D. N. 2013. Classifying and valuing ecosystem services for urban planning. Ecological Economics, 86, 235-245.
Hallmann, C. A., Sorg, M., Jongejans, E., Siepel, H., Hofland, N., Schwan, H., … & Goulson, D. 2017. More than 75 percent decline over 27 years in total flying insect biomass in protected areas. PloS one, 12(10), e0185809.
Hanski, I., von Hertzen, L., Fyhrquist, N., Koskinen, K., Torppa, K., Laatikainen, T., … & Vartiainen, E. 2012. Environmental biodiversity, human microbiota, and allergy are interrelated. Proceedings of the National Academy of Sciences, 109(21), 8334-8339.
Kukk, T., & Kull, K. (1997). Puisniidud. Estonia Maritima, 2(1), 1–249.
Lovasi, G. S., Quinn, J. W., Neckerman, K. M., Perzanowski, M. S., & Rundle, A. (2008). Children living in areas with more street trees have lower prevalence of asthma. Journal of Epidemiology & Community Health, 62(7), 647-649.
Mägi, M. 2014. Pärnu inimeste suhtumisest rannaniitude taastamisse. Pärnu Postimees 22.08.2014
Vaaks, H. 2017. Elurikkus linnas – Linnalooduse potentsiaal bioloogilise mitmekesisuse säilitamiseks. Bakalaureusetöö, Tartu Ülikool, bioloogia õppekava.
In Estonia and in Europe in general, human activities, such as mowing and pasturing, have been instrumental in cultivating and preserving grassland communities for thousands of years. Scientists, however, are currently engaged in a heated debate over the openness of our landscapes before the appearance of primitive agriculture. According to the view which at present is gaining currency in the academic community, numerous wild large grass-eating animals (such as aurochs, mammoths and many others) who no longer exist kept our landscapes similar to wooded meadows, which, in fact, could be Europe’s ancient natural ecosystems whose emergence predates human activity.