Biologia: Kaupunkiekologia (lukio)

Summary

This script delves into urban ecology, highlighting the significant role it plays as over 50% of the world's population resides in cities—a trend that's escalating. It explores the urban heat effect, increased rainfall, and the impact of these factors on city ecosystems. The script also discusses the importance of green infrastructure, such as green roofs and urban parks, in enhancing biodiversity and mitigating environmental issues. Furthermore, it touches on the adaptability of urban wildlife and concepts like metapopulations, ecological corridors, and managed neglect as strategies for sustainable urban development.

Takeaways

• 🌳 Urban ecology is a significant and growing field of study as more than 50% of the world's population now lives in cities, with this proportion expected to increase to 70-80% within 50 years.
• 🏙️ Cities are characterized by high levels of built surfaces which have a substantial impact on the abiotic conditions, such as urban heat effect where temperatures are on average a few degrees higher than surrounding areas.
• 🌡️ The urban heat effect is primarily due to the materials of city surfaces that efficiently absorb heat radiation and the low reflectivity due to dark surfaces.
• 🌧️ Cities tend to have higher average rainfall than surrounding areas due to the presence of more condensation nuclei from pollutants, which can also be influenced by human activities like cloud seeding.
• 💧 Rainwater in cities often does not infiltrate the ground due to extensive paving, leading to surface runoff and potential flooding, as well as a lack of groundwater replenishment.
• ❄️ Snowfall in cities can be significant during winter, but unlike in natural systems, it is quickly removed by human activities, affecting the local ecology.
• 🌞 Light pollution is a typical feature of urban ecosystems, affecting both plants and animals, and can disrupt behaviors, hormonal functions, and navigation abilities.
• 🌆 Noise pollution is associated with cities and can alter animal behaviors, such as birds simplifying their songs to be heard over the urban soundscape.
• 🌿 Urban green spaces, such as parks and rooftop gardens, are important for biodiversity, water retention, and improving air quality, but their integration into urban planning is still in early stages in some regions.
• 🌼 Urban flora often consists of a high number of non-native species introduced by humans, which must adapt to the unique conditions of city life, such as dealing with drought and pollution.
• 🐦 Urban animals often have a commensal relationship with humans, relying on human-generated waste for sustenance, and can exhibit behavioral changes to adapt to the urban environment.

Q & A

What is urban ecology and why is it significant?

Urban ecology, also known as city ecology, is a branch of ecology that studies urban environments, particularly densely built-up areas. It is significant because it examines how materials cycle, how organisms behave, and what happens to populations within these environments, which is crucial as more than 50% of the global population now lives in cities.

What is the current urbanization rate globally and in Finland?

Globally, over 50% of people live in cities, and this percentage is expected to increase. In Finland, the urbanization rate is even higher, with approximately 80-90% of the population residing in urban areas.

How does the urban heat effect differ from natural ecosystems?

The urban heat effect is a phenomenon where urban areas have higher temperatures than surrounding regions due to materials used in city surfaces that efficiently absorb heat radiation and the generally low reflectivity of these surfaces. This leads to average temperatures being a couple of degrees higher in cities compared to rural areas.

What is the impact of urbanization on precipitation patterns?

Urban areas tend to have higher average rainfall due to the presence of more condensation nuclei from pollutants, which facilitate the formation of rain. However, the water does not stay in the urban system as it often runs off due to impervious surfaces like asphalt and is removed through drainage systems.

Why does snow not remain in cities as it does in rural areas?

Snow does not remain in cities for long because it is actively removed by human activities such as plowing and salting. This removal of snow affects organisms by eliminating the protective layer that snow provides in rural areas.

How does light pollution in cities affect organisms and humans?

Light pollution in urban ecosystems can disrupt the hormonal functions and seasonal rhythms of animals, complicate insect navigation, and affect plants' pollination. For humans, it can impact sleep patterns and overall health.

What is the role of green infrastructure in urban planning?

Green infrastructure refers to the integration of vegetation into urban planning, such as incorporating plants into building walls or roofs, or designing urban parks. It helps in increasing biodiversity, managing stormwater, and providing aesthetic and health benefits to urban residents.

What challenges does green roofing face in Finland, and what are the potential benefits?

Green roofing in Finland faces challenges due to the short growing season and the need to withstand heavy snow loads. However, the benefits include water retention to prevent flash floods, increased biodiversity, aesthetic value, and potential energy savings by insulating buildings.

How do urban animals differ from their rural counterparts?

Urban animals often have a commensal relationship with humans, relying on human-generated waste for food. They tend to be more generalist in their ecological niche, adaptable to disturbances caused by human activities, and may exhibit behavioral changes to thrive in urban environments.

What is the concept of metapopulations in the context of urban ecology?

A metapopulation is a group of populations that interact with each other, often moving between different habitats. In urban ecology, metapopulations are relevant because cities are fragmented, creating a network of habitats where species can move and interact, which is crucial for preventing local extinctions.

What is the ecological corridor and its significance in urban environments?

An ecological corridor is a route that connects two habitats, allowing species to move between them. In urban environments, these corridors can prevent habitat isolation and promote gene flow, which is essential for maintaining biodiversity and preventing local extinctions.

What is managed neglect and how does it contribute to urban biodiversity?

Managed neglect is a strategy where urban green spaces are left relatively undisturbed, allowing for natural processes like plant succession to occur. This approach can increase plant diversity and provide habitats for various species, contributing to the overall biodiversity of urban areas.

What is the edge effect and how does it influence biodiversity in cities?

The edge effect is a phenomenon where the boundaries between two different habitats have higher biodiversity than the habitats themselves. In urban settings, the edge effect is pronounced due to the abundance of habitat edges, allowing species to exploit resources from both adjacent ecosystems.