Landscape ecology is the study of how ecological processes in the environment interact with specific ecosystems. This study happens across different sizes of landscapes, patterns of land use, and levels of research and policy. Landscape ecology can be described as the study of how different types of life and land features work together to create landscape diversity.

As a field that combines many areas of science, landscape ecology uses methods from both natural and social sciences. It looks at landscapes, which are areas with varied features like forests, grasslands, lakes, and human-made environments such as farms and cities.

The most important parts of landscape ecology are its focus on how patterns, processes, and scales are connected, and its attention to large-scale environmental issues. These topics require combining knowledge from both natural and social sciences. Important research areas include how ecosystems function in different land patterns, changes in land use and cover, how to compare different scales of study, how to link landscape patterns with ecological processes, and how to protect and manage landscapes for the future. Landscape ecology also examines how human activities affect landscape diversity and may lead to the spread of new diseases that can cause widespread illness.

Terminology

The German word Landschaftsökologie, which means landscape ecology, was created by German geographer Carl Troll in 1939. He introduced this term and many early ideas about landscape ecology as part of his work. His research involved using pictures taken from the air to study how the environment and plants interact.

Explanation

Heterogeneity refers to the way different parts of a landscape vary from each other. Landscape ecology studies how the arrangement of these parts affects the number of living things in an area and how the landscape itself works. This includes examining how the pattern, or the way features are organized, influences the ongoing activities of organisms. It also involves geomorphology, which is the study of how natural landforms, such as mountains or rivers, shape the structure of a landscape.

History

One important idea in landscape ecology came from MacArthur and Wilson's book The Theory of Island Biogeography. This work explained how the variety of life on islands is shaped by two main factors: new species arriving from nearby areas and the random loss of species over time. Later, Levins expanded this idea by applying it to non-island areas, such as forests in farmland, using a model called the metapopulation model. This helped scientists study how broken-up habitats affect wildlife survival. The growth of landscape ecology was also helped by tools like geographic information systems (GIS) and large sets of habitat data, such as satellite images.

Landscape ecology began in Europe with studies of human-altered landscapes. In North America, ideas from general ecology were combined with new approaches. While general ecology focused on studying small, similar groups of living things (like ecosystems, species, and communities), landscape ecology looked at how environments change over time and space, including changes caused by humans.

By 1980, landscape ecology became its own field. In 1982, the International Association for Landscape Ecology (IALE) was created to support its growth. Important books, such as those by Naveh and Lieberman and Forman and Godron, helped define the field. Forman noted that even though studying how human-scale landscapes work was a new idea, it had great potential for future research.

Today, landscape ecology continues to grow because of the need to solve problems in changing environments. It uses advanced tools like remote sensing, GIS, and computer models. Scientists also use mathematical methods to study how patterns in the environment affect processes like the movement of energy or species. For example, GIS maps, plant types, and rainfall data can help calculate how much carbon is stored in soil across a landscape. Remote sensing has also helped link landscape ecology to predicting plant types in different areas, as shown by work from Janet Franklin.

Now, there are at least six different ways to understand landscape ecology:

• Interdisciplinary analysis of landscape units: Landscapes are defined by how land is used, such as farming or building. Scientists study how these landscapes can support human needs by using knowledge from many natural sciences.

• Topological ecology at the landscape scale: A landscape is a large area with many ecosystems (like forests, wetlands, and villages) that repeat in similar patterns. Scientists study how these ecosystems interact and how energy, nutrients, and species move between them to help manage land use.

• Organism-centered, multi-scale topological ecology: This approach focuses on how landscapes affect living things, regardless of human interests. A landscape is seen as a "template" that shapes ecological processes, with species, not humans, as the main focus.

• Topological ecology at the landscape level of biological organization: This view uses the idea that nature works at many scales. Scientists study how ecosystems interact at a larger scale, forming a "landscape" level that connects ecosystems through strong interactions and specific patterns.

• Analysis of social-ecological systems: This approach combines natural sciences with social sciences and humanities to study how human societies and their environments shape each other. It sees landscapes as systems where human and natural systems co-evolve together.

• Ecology guided by cultural meanings of landscapes: This view focuses on preserving landscapes that have cultural, aesthetic, or symbolic value. Scientists study how to protect ecosystems and species that support these landscapes while meeting human needs like food, clean water, and other services.

Relationship to ecological theory

Some research programs in landscape ecology, especially those from the European tradition, may not fit within the traditional areas of scientific study because they examine large and varied regions. However, general ecology is important to landscape ecology in many ways. Landscape ecology includes four main ideas: how different patterns in the environment change over time, how different parts of a landscape connect and interact, how these patterns affect both living and non-living things, and how these patterns can be managed. Unlike traditional ecology, which often assumes environments are uniform, landscape ecology focuses on how patterns in space influence ecosystems.

Important terms

Landscape ecology introduced new terms and used existing ecological terms in new ways. Many terms in landscape ecology are connected and related, just like the field itself.

The word "landscape" is a key idea in landscape ecology. However, it is defined in different ways. For example, Carl Troll sees landscape as a real, natural area rather than a made-up idea. Ernst Neef describes landscapes as parts of the Earth’s natural systems that are grouped based on similar land use. Richard Forman and Michel Godron define a landscape as a large, mixed area made of different ecosystems, such as forests, meadows, and villages, and say a landscape should be at least a few kilometers wide. John A. Wiens disagrees with some traditional views that focus on human interactions with nature on a large scale. Instead, he says a landscape is a "template" that shows how patterns in space affect ecological processes. Some people define a landscape as an area that includes two or more ecosystems close to each other.

A major concept in landscape ecology is "scale." Scale shows how distances on a map relate to real-world distances. It also describes the size or detail of an object or process. Scale has three parts: composition, structure, and function. Composition refers to the number and types of patches (see below) in a landscape and how common they are. For example, the amount of forest or wetland, the length of forest edges, or the number of roads can describe a landscape’s composition. Structure depends on how patches are arranged and their proportions. Function describes how parts of a landscape interact based on life cycles. "Pattern" refers to how a landscape’s parts are organized.

A landscape with structure and pattern means it has spatial heterogeneity, or uneven distribution of features. Heterogeneity is a key part of landscape ecology that makes it different from other types of ecology. Heterogeneity can be measured using methods like agent-based modeling.

A "patch" is a basic unit in landscape ecology. It is a relatively uniform area that stands out from its surroundings. Patches change over time through a process called "patch dynamics." Patches have clear shapes and arrangements and can be described by details like the number of trees, types of trees, or tree height.

The "matrix" is the main background system of a landscape that connects other parts. Connectivity measures how well corridors, networks, or matrices are linked. For example, a forested landscape (matrix) with fewer open spaces has higher connectivity. Corridors are strips of land that differ from nearby areas. A network is a system of connected corridors. A "mosaic" describes the overall pattern of patches, corridors, and matrix in a landscape.

Patches in a landscape are separated by boundaries, which can be clear or unclear. The area where two ecosystems meet is called a boundary. An "edge" is the part of an ecosystem near its edge, where conditions differ from the inside. Edge effects can change the types and numbers of species found there. For example, where a forest meets a grassland, the edge is where they join. In a continuous landscape, like a forest turning into open woodland, the edge is less clear and may depend on local changes, like when tree cover drops below 35%.

An "ecotone" is a transitional area between two communities. It can form naturally, like a lakeshore, or be created by humans, like a field cleared from a forest. Ecotones often have species not found in the surrounding areas. Examples include fencerows, forest-to-meadow transitions, or riverbanks in forests. Ecotones have sharp vegetation changes, mix of communities, and more species than nearby areas.

An "ecocline" is a gradual change in environmental conditions across an area. Ecoclines help explain how organisms are distributed because some survive better under certain conditions. They have diverse, stable communities. An "ecotope" is the smallest distinct unit used to map and classify landscapes. It is a uniform area that helps study landscapes and changes over time.

"Disturbance" is an event that changes a system’s structure or function. "Fragmentation" is when a habitat or land type is split into smaller parts. Disturbance is often a natural process. Fragmentation causes land transformation, which is important as landscapes develop.

Repeated clearing, whether from natural events or human actions, can break large areas into small, isolated patches. This happens when the cleared area is large enough, causing landscapes to shift between connected and disconnected states.

Theory

Landscape ecology theory explains how human activities affect the structure and function of landscapes. It also suggests ways to repair damaged landscapes. This theory clearly includes humans as a cause of changes in how landscapes work. A key idea in landscape ecology is the landscape stability principle, which shows how having many different types of land features helps landscapes resist damage, recover from harm, and stay stable overall. This idea is an important part of general ecological theories that focus on how different parts of a landscape are connected.

Keeping different parts of a landscape intact helps protect them from outside threats, such as building projects or changes in how land is used. Studies about how land use changes over time have used a strong geographical approach, leading to the understanding that landscapes can serve many purposes. Some experts (Bastian, 2001) say a more unified theory of landscape ecology is still needed because ecologists have different opinions about it, and it involves many scientific fields.

A related theory is hierarchy theory, which describes how systems made of separate parts work together at different levels. For example, a forested area might be divided into drainage basins, which contain smaller ecosystems, which include individual trees and open spaces. Recent research in landscape ecology has focused on how the patterns of land features relate to ecological processes and how changes in size affect the ability to apply findings across different areas. Some studies show that landscapes can reach points where small changes, like slight temperature shifts, lead to major changes in ecological processes, such as the spread of an invasive species that takes over an area.

Application

Developments in landscape ecology show how patterns in the environment relate to natural processes. These studies use math-based methods to connect how things are arranged in space and time with changes in the environment. This connection helps people create plans to solve environmental issues. More attention in recent years on how environments change over time has shown the need for new math-based tools to study patterns, understand how natural processes work in specific areas, and build reliable models. Scientists often use statistical methods, like cluster analysis, canonical correspondence analysis (CCA), or detrended correspondence analysis (DCA), to group types of plants. Another method, gradient analysis, helps scientists study how plants are arranged across an area or identify important wetland areas for protection or restoration (Choesin and Boerner 2002).

Climate change is a major factor in current research about landscapes. Ecotones, which are areas where two environments meet, are important for managing landscapes under climate change because changes often first appear in these unstable areas. Studies in northern regions, like Norway, have looked at natural processes such as snow accumulation, melting, freezing, water movement, soil moisture, and temperature over long periods. These studies compare differences between ecosystems in mountain areas to understand how animals are distributed. Observing where animals live and how plants change over time can help scientists learn about long-term changes in snow and ice across landscapes.

Other studies suggest that human activities are the main reason landscapes look the way they do in many parts of the world. Landscapes can act as a way to measure biodiversity because the types of plants and animals found in different areas may vary. Species can move from one habitat to another, which affects how landscapes function. As humans use more land and create more edges between habitats, the movement of species across these edges may become more important for protecting wildlife. This is because species might survive in larger areas even if they are not found in smaller, local areas.

Land change modeling is a tool used in landscape ecology to predict how land use will change in the future. These models help planners, geographers, and others understand how landscapes develop. In recent years, much of Earth’s land cover has changed quickly, whether due to cutting down forests or expanding cities.

Landscape ecology is used in many areas of science. For example, it is closely connected to land change science, which studies how land use and cover changes affect the environment. Another recent focus is applying spatial ideas to the study of lakes, rivers, and wetlands in landscape limnology. Seascape ecology is a version of landscape ecology used in oceans and coastal areas. Landscape ecology also helps in fields like farming and forestry. In farming, it has provided new ways to manage problems caused by intensive farming. Farming has always had a big impact on ecosystems.

In forestry, how forests are managed for wood, fuel, or beauty has influenced how forests are protected and used. Landscape forestry uses tools and methods to help manage forests. Landscape ecology has helped shape the study of fish populations and is often used in wetland studies. It has also helped create plans for managing landscapes overall. Finally, landscape ecology has played a key role in advancing efforts to make the world more sustainable. For example, a recent study looked at how cities in Europe can grow in a way that protects the environment using tools from landscape ecology.

Landscape ecology has also been combined with the study of genetics to create a field called landscape genetics. This field studies how features in the environment affect how species move and share genes over time. It also looks at how the quality of the area between habitats, called the "matrix," influences genetic differences. After the term was first used in 2003, over 655 studies on landscape genetics were published by 2010, and the field continues to grow. As genetic information becomes easier to use, scientists are finding new ways to study how landscapes affect evolution and ecosystems, especially in areas changed by humans, where many species are disappearing.