Biologia: Kaupunkiekologia (lukio)

Otavian oppimateriaalit

17 Nov 202118:01

Summary

TLDRThis 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.

Outlines

00:00

🌳 Urban Ecology and Its Impact on Environment

The first paragraph introduces urban ecology, emphasizing its significant role in studying city environments. It discusses the rapid urbanization trend, with over 50% of the world's population living in cities, a proportion expected to increase to 70-80% within 50 years. Urban ecology focuses on the study of densely built environments, examining material cycles, organism behavior, and population dynamics within cities. The script highlights the urban heat effect, where city temperatures are higher due to materials absorbing heat radiation and the lack of vegetation and evaporative cooling. It also mentions higher precipitation in cities due to increased aerosols from pollution, but notes that this water quickly drains away due to impermeable surfaces, leading to potential flooding and lack of groundwater replenishment. The paragraph concludes with the observation that snow in cities does not persist, affecting organisms that rely on it for protection.

05:07

🌆 Effects of Urbanization on Wildlife and Ecosystems

This paragraph delves into the effects of urbanization on wildlife, including disruptions to hormonal functions and seasonal rhythms in animals, navigation issues for insects, and the impact on plant pollination. It also touches on the effects of light pollution on human health and bird song patterns, which have adapted to the noise levels in cities. The discussion extends to noise and chemical pollution, which are more prevalent in urban areas and affect air quality, a significant issue in many Asian cities. However, the script notes that Finland has relatively good air quality, largely due to its geographical features. The paragraph also highlights the importance of green spaces within cities, such as Central Park in New York, and the concept of urban fragmentation affecting biodiversity and living conditions.

10:10

🌻 Urban Flora and the Role of Green Infrastructure

The third paragraph focuses on urban flora, noting that primary production in cities is much lower than in surrounding natural systems due to limited surface area for plant growth. Despite this, cities host a variety of plant species, often introduced by humans. The script discusses the importance of green infrastructure in urban planning, such as integrating vegetation into buildings and designing green spaces that blend into the urban environment. It mentions the early stages of green roofing in Finland, with research into lightweight moss roofing systems that can retain rainwater, increase biodiversity, and provide thermal benefits to buildings. The paragraph also considers the challenges of implementing such systems in Finland's climate, with its short growing season and heavy snow loads.

15:14

🐦 Urban Fauna and Ecological Concepts in Cities

The final paragraph explores the characteristics of urban animals, which often have a commensal relationship with humans, relying on human-generated waste. Urban species tend to be ecological generalists, adaptable to various food sources and disturbances. The script notes behavioral changes in urban animals due to the different selective pressures of the urban environment, such as the spread of boldness and curiosity in city systems. Examples of successful urban species, like the city pigeon and the seagull, are provided, along with the concept of metapopulations and the importance of ecological corridors to prevent local extinctions. The paragraph concludes with the idea of managed neglect in urban green spaces to increase plant diversity and the concept of edge effects, where biodiversity is higher at the boundaries of different ecosystems, a common feature in urban environments.

Mindmap

Keywords

💡Urban Ecology

Urban Ecology is the study of ecosystems within urban environments, focusing on the interactions between human-made structures and natural processes. It is a key theme in the video, which discusses the ecological impact of urbanization and how it shapes the habitats and behaviors of organisms within cities. The script mentions urban ecology's significant role and its future importance as more people migrate to urban areas.

💡Urban Heat Effect

The Urban Heat Effect refers to the phenomenon where the temperature in cities is significantly higher than in surrounding rural areas due to the absorption of heat by urban surfaces and the lack of reflective surfaces. The video script illustrates this concept by explaining how city materials, such as dark surfaces, absorb heat and contribute to higher average temperatures in urban areas.

💡Biodiversity

Biodiversity is the variety of life in a given area, including the number of species and their genetic diversity. The script relates to biodiversity by discussing how urbanization affects the types of species that can thrive in cities, often leading to an increase in non-native species and a decrease in native flora due to limited surface area for growth.

💡Green Roofs

Green Roofs are roofing systems that are partially or completely covered with vegetation, integrated into urban planning and construction. The video script discusses green roofs as an example of urban ecology practices, which can help retain rainwater, increase biodiversity, and provide insulation for buildings. The Meilahti research roof in Helsinki is mentioned as a current research example.

💡Urban Wildlife

Urban Wildlife refers to animals that have adapted to living in urban environments. The script describes urban wildlife by highlighting species like the city fox and the gull, which have developed relationships with humans and adapted to urban conditions, sometimes becoming pests or thriving in the urban ecosystem.

💡Metapopulation

A Metapopulation is a population of a species that occupies a large area and consists of several smaller populations that interact with each other. The video script uses the concept of metapopulations to explain how urban areas, being fragmented, can support these interconnected populations, which is important for the genetic diversity and survival of species.

💡Ecological Corridors

Ecological Corridors are strips of land that connect separate areas of habitat, allowing wildlife to move between them. The script discusses ecological corridors in the context of urban ecology, suggesting that they can help prevent local extinctions by providing pathways for species to move between fragmented habitats within cities.

💡Managed Wildness

Managed Wildness refers to the approach of allowing urban green spaces to be less manicured and more natural, which can increase plant diversity and create a more natural habitat for wildlife. The video script suggests that this approach can enhance biodiversity in urban areas by allowing grasses to grow longer and leaving some dead wood for wildlife.

💡Edge Effect

The Edge Effect is a phenomenon where the boundary areas between two different ecosystems have higher biodiversity than the ecosystems themselves. The script mentions the edge effect in urban ecology, noting that cities, with their many boundary areas, can provide rich habitats for a variety of species that can exploit resources from both sides of the boundary.

💡Urbanization

Urbanization is the process where more people move to urban areas, leading to the growth of cities and a decrease in rural populations. The video script discusses urbanization as a major trend, with over 50% of the world's population living in cities currently, and projections that 70-80% will live in cities within 50 years, highlighting the importance of urban ecology in understanding these changes.

💡Sewage Systems

Sewage Systems are infrastructure designed to collect and dispose of wastewater from homes and businesses. The script mentions sewage systems in the context of urban ecology, discussing how heavy rain can overwhelm these systems, leading to flash floods and water pollution, which is a significant issue in urban environments.

Highlights

Urban ecology plays a significant role in understanding the ecological impacts of urbanization, which is increasing as more people move to cities.

Over 50% of the world's population currently lives in cities, with some countries like Finland having an urbanization rate of 80-90%.

By the next 50 years, it's predicted that 70-80% of the world's population will reside in urban areas.

Urban ecology is a subfield of ecology that focuses on the study of urban environments and their densely built structures.

Urban ecologists are interested in the same aspects as ecologists, such as material cycles, behavior of organisms, and population dynamics within the city.

The urban heat effect is a phenomenon where cities have higher average temperatures than surrounding areas, primarily due to the materials of urban surfaces absorbing heat radiation efficiently.

Urban areas tend to have less vegetation and evapotranspiration, contributing to higher temperatures.

Rainfall is generally higher in cities due to the presence of more condensation nuclei from pollutants, which aids in rain formation.

In cities, rainwater does not infiltrate the soil due to extensive paving, leading to surface runoff and potential flooding.

Snowfall in cities can be significant during winter, but it is quickly removed by human activities, affecting the local ecosystem.

Light pollution in urban areas can disrupt the behavior and biological rhythms of both plants and animals, including humans.

Noise pollution in cities has been shown to alter bird songs, requiring them to sing louder and simplify their songs.

Chemical and particle pollution are more prevalent in cities, affecting air quality and impacting the health of urban inhabitants.

Green spaces like Central Park in New York City are important for urban ecosystems, providing habitats and reducing the fragmentation of living environments.

Green infrastructure, such as green roofs, can help retain rainwater, increase biodiversity, and provide insulation for buildings.

Urban plants often have to adapt to drought conditions due to rapid runoff of rainwater in paved areas.

Animals in cities often have a commensal relationship with humans, relying on human-generated waste for sustenance.

Behavioral changes in urban animals are common as they adapt to the urban environment, which selects for different traits compared to natural systems.

The concept of managed neglect in urban green spaces, allowing for more natural growth and less maintenance, can increase biodiversity.

Edge effects, where the boundaries between different ecosystems increase biodiversity, are prominent in urban environments due to their fragmented nature.

Ecological corridors, such as overpasses for wildlife, can help connect fragmented habitats in urban areas and prevent local extinctions.