Landscape ecology is the study of the pattern and process of ecosystems at a regional or landscape scale. It is a subfield of ecology that focuses on the interactions between the physical environment and the distribution and abundance of species, as well as the interactions between different ecosystems within a region.
Landscape ecologists may study a wide range of topics, including the patterns of land use and land cover in a region, the impacts of habitat fragmentation on species distribution and abundance, and the ways in which species and ecosystems respond to and are affected by environmental changes such as climate change and urbanization.
To study landscape dynamics, landscape ecologists may use a variety of methods, including field observations, experiments, and data analysis. They may also use tools such as geographic information systems (GIS) and remote sensing to analyze and map landscape patterns and processes.
Landscape ecology is an important field for understanding the functioning of ecosystems at a regional scale and for informing conservation efforts to protect and preserve species and their habitats. It is also important for understanding the impacts of human activities on ecosystems and the ways in which these impacts can be managed or mitigated.
All the living components of an ecosystem form a single community or bio-community co-existing together. A community is mainly attributed to characteristics like the co-occurrence of species, reoccurrence of groups of the same species, and homeostasis or self-regulation. Krebs (1994) defined community as ‘an aggregation of the populations of living organisms in a specified habitat .’According to Clarke (1954), the definition of a community is a group of mutually adjusted plants and animals living together in a natural area. A community always comprises plants and animals, as both are very much essential for the survival and functioning of the community.
In a community, there are various interactions between the populations of two species, resulting in the combinations like neutral (0, 0), positive (+, +), and negative (-,-). The interactions are ecologically essential and are of nine types. Among them, neutralism, direct interference type of competition, resource use type of competition, amensalism, parasitism, and predation are Negative Interactions, whereas commensalism, proto-cooperation, and mutualism are Positive Interactions.
Neutralism:
Neither of the population is affected by the interaction with each other. Example: The two closely related species of aquatic birds, the shag (Phalacrocorax aristotelis) and the cormorant (Phalacrocorax carbo), found in England living together during the breeding season, feeding in different kinds of fishes with no competition. Similarly, the tide pool communities show neutralism type of interaction; even if they exist together, many neither benefit nor harm one another. Its symbol is (0, 0).
Interference competition
Interference competition (direct interference type): In this type of interaction, both populations hinder each other. An interspecific match occurs when two species come into direct contact with each other such as fighting or defending a territory. Its symbol is (-,-).
Exploitation competition
Exploitation competition (resource use type): In this type of interaction, both populations badly affect one another during the struggle for resources during scarcity. Its symbol is (-,-). One species exploits a resource such as food, space, or prey along with another without direct contact.
The competition between the populations can involve space, nutrients, light, waste materials, susceptibility to carnivores, disease, and many other types of mutual interactions. The results of the competition have been studied by many evolutionary biologists as one of the mechanisms of natural selection. The development of interspecific competition can be equilibrium adjustment between the two species or, if severe, replacement of one species population by another, or forcing the other to occupy another space or to use another food.
Competition exclusion principle or Gause principle
Here is a clear case of exploitation competition. The inhabitation of closely related organisms having similar habits or morphologies in the same place merely occurs. The Russian biologist Gause (1932) explained the ecological separation of closely related species as the ‘Gause principle’ or ‘complete exclusion principle .’He first observed such separation of the closely related species of ciliate protozoans Paramecium caudatum and Paramecium aurelia in experimental cultures. When both species were grown in separate cultures, they exhibited typical sigmoid population growth. They maintained a constant population level in the culture medium that was maintained with a fixed density of food items (bacteria that did not multiply themselves in the medium and thus could be added at frequent intervals to keep the food density constant). When both protozoans were placed together in the same culture, Paramecium aurelia alone survived after 16 days. Neither of them attacked the other or secreted harmful substances. Still, populations of Paramecium aurelia had a high rapid growth (high intrinsic rate of increase). They thus replaced Paramecium caudatum due to the limited amount of food under the existing conditions.
The experiment done by taking Paramecium caudatum and Paramecium bursaria gave the opposite result. Although both protozoans were competing for the same food, Paramecium bursaria occupied a different part of the culture and fed upon the bacteria without disturbing Paramecium caudatum. Thus, both ciliate protozoans could survive and reach a stable equilibrium in the same culture medium. In this case, the habitat was sufficiently different for the two species to co-exist, although their food was identical.
The most widely debated theoretical aspects of competition theory revolve around the Lotka-Volterra equations. This equation was proposed by Lotka (1925) and Volterra (1926). These equations are useful for modeling predator-prey, parasite-host, competition, or other two-species interactions. In terms of the competition within a limited space, the simultaneous growth equations of the populations can be written using the logical equation:
Where N1 and N2 are the numbers of species 1 and 2, respectively,
K is the equilibrium level.
A is the competition coefficient indicating the inhibitory effect of species 2 on species 1.
b is the corresponding competition coefficient signifying the inhibition of species 1 on species 2.
- Amensalism: In this interaction, one population is harmed, whereas the other is not affected. Its symbol is (-, 0). Lawton and Hassell (1981) refer to this interaction as asymmetrical competition. Example: penicillin killing bacteria.
- Commensalism: In this type of relationship, among the two living organisms, one organism benefits from the other without causing any harm to it. Examples: The tree frog uses plants for protection. The cattle egrets eat up the insects residing upon the back of the cattle during their grazing time. The golden jackal following a tiger’s trail and feeding upon its prey remains when it is expelled from its pack. Its symbol is (+,-).
- Parasitism: When parasites colonize a host, the host is said to have an infection. The parasite gets shelter and nutrition as benefits from the host, whereas the host gets a disease when the infection gives rise to symptoms that are clearly harmful to the host. Its symbol is (+, -). Example: fleas or ticks that live on dogs and cats.
- Predation: In this type of interaction, one population adversely affects the other by the direct attack but somehow depends on the other for survival. Its symbol is (+, -). It is of two types: true predation and herbivory.
- True Predation: In this type of predation, a predator kills and consumes a prey species. True predators are carnivores like tigers and birds of prey. Examples: tiger predating upon the deer, leopard killing livestock, etc.
- Herbivory: In this type of predation, a herbivorous animal is a predator which feeds upon the plants (prey). Large herbivores like sheep, cattle, kangaroos, etc., are known as grazers. Other herbivores include insects, molluscs, fish, etc.
- Proto-cooperation: In this type of interaction, both populations benefit from their association but do not have an obligatory relationship. This means the benefits provided by both populations only increase the size or growth rate of the population but are not compulsorily important for their growth or survival. Thus, this interaction is also called facultative cooperation. Its symbol is (+, +). Example: red-billed oxpecker and black rhinoceros, crocodile bird (Pluvianus aegyptius) entering the open mouth of a crocodile and making it free from leeches.
- Mutualism: In this type of interaction, both populations are benefitted from each other’s survival and growth and cannot survive without each other under natural conditions at the same time. Flowering plants and pollinators display both facultative and obligate mutualism. Obligate mutualism is shown by termites and endosymbiotic bacteria, parasitoid wasps, and Polyana viruses. Its symbol is (+, +).
Concept of Habitat, Ecological Niche, and Guild
Habitat: It is the place where an organism lives or where one would go to find it. The habitat can also be defined as the place occupied by an entire community. The habitat of an organism or a group of organisms (population) includes other organisms and the abiotic environment.
Ecological Niche describes the specific role a population plays within an ecosystem. The environmental Niche can be defined by their interaction with another organism (E.g., predator or prey) or the role played in nutrient cycling (E.g., primary producer or decomposer). It not only includes the physical space occupied by an organism but also its functional role in the community and its position in environmental gradients of temperature, moisture, pH, soil, etc.
Charles Elton (1927) first used the term ‘niche’ in the sense of the ‘functional status of an organism in its community .’The Niche in terms of microhabitat is called ‘spatial niche’ whereas, in terms of the importance of energy, relations are known as ‘trophic niche .’G.E. Hutchinson (1957) designated niche as ‘multidimensional or hypervolume niche’ which can be measured and mathematically manipulated. For example, a two-dimensional climograph, which depicts the x-and y-axes of a particular species of a bird and a fruit fly, could be expanded as a series of coordinates (x, y, and z axes) to include other environmental dimensions.
Hutchinson (1965) differentiated Niches into two main types: fundamental Niches and realized niches.
- Fundamental Niche is the potential set of conditions a species can occupy. It can be determined experimentally. It is the Niche before the competition, predation, etc.
- Realized Niche: Due to the effects of competition, enemies, and biogeography in nature, the species only partially occupied the Niche. This is known as the realized Niche. It is the Niche after the competition, predation, etc.
The Niche can be further divided into two distinct aspects: alpha niche and beta niche.
- Geographic Niche, conditions niche, or beta niche: In this type of Niche, some species live in different places due to variations in environmental tolerances. So, species with other beta niches never physically come together to interact.
- Resource–specialization niche or alpha niche: In this type of Niche, several species can occur in the same place, which means that they have the same beta niche. Two species having different alpha niches imply that they are using different resources or are using similar resources in such a way that overlap in their use is minimized.
Guilds: They are groups of species with comparable roles and niche dimensions within a community. For example, a group of fruit-eating birds in a rainforest, a guild of forest-floor dwelling herbs, wasps parasitizing herbivore population, nectar-feeding insects, snails living in the forest floor litter, and vines climbing into the canopy of a tropical forest.
The ecologically equivalent species are those species that occupy the same Niche in different geological regions (continents and major oceans). The species composition of the communities differs widely in different floral and faunal regions, but similar ecosystems develop equivalent functional niches wherever physical conditions are similar, regardless of the geographical location.
The ‘habitat’ can be regarded as the ‘address’ of the organism, ‘niche’ as its ‘profession,’ and its trophic position in food webs as how it lives and interacts with the physical environment and with other organisms in the community.
FAQs on Landscape Ecology
Why is landscape ecology important?
Landscape ecology is important due to the following reasons because:
– It helps in the study of landscape structure, composition, function and processes.
– It links the ecological theory with practical applications.
– It helps to study of the exchange of biotic and abiotic materials among ecosystems.
– It helps in better land use planning, land resources use management, urban planning, management of habitat corridors, etc.
What are the characteristics of landscape ecology?
The characteristics of landscape ecology have been described as follows:
Patches: Their size and shape influence the structure of community. Large habitat patches contain more individuals, i.e. larger population size and more species i.e. increased species richness. Carnivores have a larger home range than herbivores.
Boundary: A boundary is a zone of contact, separation or transition between patches that offer diverse conditions and habitats for plants and animals.
Habitat Corridors: They connect the different wildlife habitats. They also serve in connecting the fragmented habitat, thus being effective in minimizing the effects of the habitat fragmentation. The strip corridor, mainly made by the humans have wider bands of vegetation with both interior and edge environments. Corridors have a wide variety of functions as travel lanes for organisms moving within their home range, as dispersal routes for individuals travelling between habitats, as filters by providing dispersal routes for some species not for others, encouraging gene flow among subpopulations and helping reestablish species in habitats where they have gone locally extinct. Some negative effects of corridors can be seen as scouting site for predators hunting in adjacent patches, as a pathway for disease or invasive species to spread, restriction of movement of social group of animals if the corridors are narrow, etc.
Matrix: They are the communities which surround a patch. Landscape comprises of mainly three main elements: patches, boundaries and corridors are embedded in the matrix.
Ecotones: They are transition of physical or biological or both habitats between two ecosystems.
Edge effects: It describes the ecological conditions and higher species in ecotones compared to either ecosystem. The predators use edges to travel, which increases predation rate in edges. Grassland birds have highest predation at edge with adjacent forest. Predation rate decreases with increasing distance from the forest edge.
Landscape connectivity: It can be known as the degree to which the landscape facilitates the movement of organisms among the patches, thus influencing the population dynamics and community structure. There are two types of landscape connectivity: structural connectivity and functional connectivity. Structural connectivity describes the degree to which the patches are physically connected with each other. Functional connectivity relates to the movement of organisms facilitated by the landscape, and it is the function of both physical structure of landscape as well as the behavioral responses of organisms to the structure.
Theory of Island Biogeography: It provides a framework to understand how patch size and connectivity can interact to influence the patterns of species richness on patches within the landscape. This theory states that the immigration rate declines with increasing species richness and the extinction rate increases. The balance between the rate of extinction and immigration (immigration rate= extinction rate) determines the equilibrium number of species (S) on the island. The number of species established on an island represents a dynamic equilibrium between the immigration of a new colonizing species and the extinction of previously established ones.
Metapopulation: These are the type of populations which occur in spatially isolated patches and there occurs significant exchange of individuals. The persistence of individuals in a landscape is affected by the rate of movement of the individuals between the subpopulations.
Lake Chemistry: In a hydrologic flow system, the lakes at the upper end are fed almost entirely by precipitation. The lake in the middle positions receive significant inputs of ground water. The lakes at the lower end receive significant surface drainage as well as ground water.
Soil and vegetation mosaics: The distribution of the perennial plants are affected by the soil structure and age. Soil mosaics contain patches of materials like sand, silt, clay, etc. deposited during the floods originating in the mountains, they can gradually change depending upon the climate.
Ecosystem Engineers: Himalaya marmots, African, elephants, beavers, etc. are regarded as the ecosystem engineers. The marmots affect the mountain landscapes by their borrowing nature resulting in soil fertility and plant diversity. African elephants due to their feeding, digging or migratory behavior are regarded as ecosystem engineers as they have the ability to change woodland to grassland. The beavers can modify the landscape structure and dynamics as they cut trees, build dams and flood the surrounding landscape, thus converting forests into wetlands.
What is Landscape in biology?
In biology, landscape generally refers to a heterogeneous area composed of several interacting ecosystems. The ecosystems can be natural (terrestrial and aquatic) and manmade ecosystem (urban and agricultural areas). Landscape is made up of an assemblage of landforms such as mountains, hills, plains, plateaus, lakes, streams, soils, natural vegetation, etc. Landscape is determined by the scale relative to the process or organism examined, not by its size. A landscape may be a few square meters or many square kilometers.
What are the 3 types of ecology?
The three types of ecology are population ecology, landscape ecology and behavioral ecology.
What is the main goal of ecology?
The main goal of ecology is to study and determine the distribution and abundance of living organisms in the environment along with the various factors affecting their presence in the ecosystem.
What are the two main branches of ecology?
Autecology and Synecology are the two main branches of ecology.
What are examples of ecology?
The examples of ecology are studying the different biogeochemical cycles occurring ecosystem, positive as well as negative interactions occurring among the living beings, study of food chains in the grassland ecosystem, etc.
Who is the father of ecology?
Eugene P Odum is known as the father of ecology.
How do you explain ecology?
Ecology is simply the study of ecosystems and the ecological processes. Ecology can be defined as the interaction between the biotic and abiotic factors of an ecosystem.
What are the 6 main types of landscapes?
The main six types of landscapes are as follows:
i. Mountains: They are elevated portion of the earth’s crust (larger than hill) with steep sides and show exposed bedrock. Mountains are the home to Snow leopard, Red panda, Tibetan gazelle, Himalayan marmot, Alpine musk deer, etc.
ii. Hills: They are less tall and less steep than the mountains but extend above the surrounding terrain. Different animals like Asamese macaque, Nepal grey langur, clouded leopard, Himalayan Black Bear, etc. are residents of the hilly region.
iii. Wetlands: Wetlands are one of the most important habitats for animals like dolphin, wild water buffalo, otter, rhino, etc. Among the wetlands found in Nepal, ten wetlands listed in Ramsar site are: Koshi Tappu wildlife reserve, Maipokhari of Ilam, Lakes of Pokhara valley, Ghodaghodi Lake of Kailali, Jagdishwor lake of Kapilvastu, Beeshazaari lake of Chitwan and four wetlands found in Himalayan region: (Rara lake, Shey Phoksundo lake. Gokyo lake and Gosainkunda lake).
iv. Forest: It is a land area fully covered by diverse form of trees. Forests are habitat to different animals like Leopard, barking deer, yellow throated marten, jackals, etc.
v. Grassland: In the hills and the high Himalayan areas, grasslands are good habitats for Thar, Ghoral, Jharal, Naur and domestic livestock. In Terai, grasslands are the homes for swamp deer, hog deer, black buck, hispid hare, Gaur, Asiatic Wild Elephant and spotted deer.
vi. Desert: Desert refers to a those barren landforms which receives less rainfall, and is covered by sand and dry soil. The animals living in desert area are camel, kangaroo rats, foxes, etc.
What is a landscape process?
The landscape process includes flow of energy, materials and species between the ecosystems within a landscape.
What is landscape format?
Landscape format refers to the spatial arrangement and connectivity of the patches. Landscape structure can be explained in terms of patch, boundary and corridor elements. The primary sources of the landscape structure or format are geological processes like volcanism, sedimentation, erosion, etc. The landscape process is affected by interactions among many factors which are abiotic or physical, natural disturbances (fire, flood, windstorm, drought, extreme cold or heat), biotic factors and human activities.
What is a landscape matrix?
Landscape matrix refers to the functional unit of the landscape in which the patches and corridors are embedded.
What is landscape diversity?
Landscape diversity refers to the different types of landscape occurring on the earth surface. They are desert, plain land, Taiga, Tundra, wetland, mountain, cliff, coast, glacier, shrub land, forest, woodland, etc.
What is a landscape mosaic?
Landscape mosaic is the product of the boundaries defined by the changes in the physical and biological structure of the distinct communities that form its elements.
What does a landscape ecologist do?
A landscape ecologist performs various types of works like:
– Their main goal is to understand and describe the landscape structure.
– They study on how landscape structure influence the movement of organisms, materials or energy between potentially suitable habitats.
– They also study why and how landscape structures change over time.
What is the difference between ecosystem and landscape?
The main difference between ecosystem and landscape is that ecosystem is the interconnecting system formed by the biotic community and abiotic components of the environment whereas landscape is an area of land territory which can be viewed by the eyes at a glance including all its components.
Landscape is a picture of the scenes of land, water resource, forest, hills, fields, etc. whereas ecosystem is more than that as it is the system operating under the functions of the ecological community as well as the various factors influencing it.
What is a primary focus of landscape ecology?
The primary focus of landscape ecology is the study of three main landscape elements i.e. matrix, patches and corridors, which are also known as the components of the landscape mosaic. The landscape ecology focuses on the factors influencing the exchanges of energy, materials and organisms across the multiple ecosystems.
– Patches are the unit of land or habitat or homogenous area which differ relatively from the adjacent surroundings. Patches may occur due to habitat fragmentation.
– The patches are interconnected to one another through corridors. Landscape corridors are thin strip of habitats that connect isolated patches of habitat. Different types of corridors can be found in landscape. They may be wide to narrow and serve as highways for organisms to move from one patch to another. Larger organisms move easily with wider corridors but, their movement is restricted when the corridors are narrow.
– Patches are surrounded by a matrix which plays an important functioning of the landscape. Patches and corridors are embedded in the matrix.