Briefly discuss the ambiguity of the term "Landscape" as employed by the two "Schools" of Landscape Ecology.
European School:
• Takes a more holistic and integrative approach.
• Focuses on the interaction between humans and the environment.
• Emphasizes cultural and socio-ecological aspects of landscapes.
North American School:
• More focused on quantitative models and spatial patterns.
• Uses metrics and mathematical analyses to understand the structure and function of landscapes.
• Focuses on patch dynamics and the movement of species/processes between patches.
Is the definition of patches in a landscape universal or specific to the organism inhabiting the patch? Explain briefly.
• Defined in relation to the organism or process being studied.
• Not universal: Varies depending on species-specific requirements or behaviors.
• Different species or ecological processes perceive patches differently.
• The definition of a patch is scale-dependent, both spatially and temporally.
Give an example about the temporal and spatial specificity of landscape processes.
• Temporal specificity: Processes such as succession or vegetation growth occur over time. For example, a forest recovering after a fire might go through different successional stages, from grassland to shrubland and finally to mature forest, each stage taking a specific amount of time.
• Spatial specificity: The effect of landscape processes varies depending on spatial context. For instance, nutrient flow in a river system will be influenced by the shape and size of the watershed or basin, affecting how nutrients are distributed spatially.
How does connectivity in rivers differ from connectivity in oceans?
Rivers:
• Connectivity in rivers is linear, meaning that movement of species or nutrients happens in a more predictable, directional flow.
• Rivers are often constrained by their banks and watersheds, limiting lateral movement and making longitudinal connectivity (upstream-downstream) more significant.
Oceans:
• Connectivity in oceans is multidirectional due to currents, tides, and other factors that allow movement in various directions.
• Oceans are much more open systems compared to rivers, allowing for more diffuse and widespread movement of species and nutrients.
Give an example of how an edge effect may be judged as positive.
• Increased biodiversity: Edges between two different habitat types can create unique conditions that support a higher diversity of species. For instance, the border between a forest and a meadow might support species from both ecosystems, along with additional species that thrive in the transition zone.
• Greater resource availability: Edge habitats often provide access to more resources, such as light or food, compared to the interior of a habitat. This can benefit certain species that exploit both environments.
Give an example of a nutrient flow largely mediated by human activity on the landscape and the global scale.
• Agricultural runoff: Human activities such as farming lead to the application of fertilizers containing nitrogen and phosphorus, which are then washed into rivers and eventually reach the oceans. This contributes to nutrient enrichment on both a landscape and global scale.
• This process can lead to eutrophication, where water bodies receive excess nutrients, promoting algal blooms that deplete oxygen and harm aquatic ecosystems.
Give an example of how humans have altered disturbance regimes.
• Fire suppression: Human activities, such as the prevention and suppression of natural fires, have significantly changed the disturbance regime in many forest ecosystems. Historically, fires played a crucial role in maintaining the health and biodiversity of certain ecosystems.
• By suppressing these fires, humans have altered the natural cycle, leading to changes in forest structure, increased fuel accumulation, and making some areas more prone to larger and more intense fires in the future.
Name 2 human activities other than climate change that alter disturbance regimes.
Deforestation:
• Large-scale removal of forests changes the natural disturbance regimes, particularly by disrupting the carbon and water cycles. Deforestation can lead to altered fire regimes and affect species that rely on periodic disturbances like wildfires or floods.
Urbanization:
• The expansion of cities changes the landscape by replacing natural areas with impervious surfaces like roads and buildings. This alters local hydrology, increases the risk of flooding, and suppresses natural processes like erosion and vegetation regeneration.
Last changeda month ago