BIOL Review

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What is the focus of landscape ecology?

Landscape ecology studies the relationship between spatial patterns and ecological processes over various scales, with a focus on large spatial scales. It is interdisciplinary, involving biology, geology geography, physics and chemistry.

What is a watershed?

A watershed is the drainage area of a stream, river, or lake that channels water to a single outlet.

What is the significance of the Hubbard Brook Forest?

Hubbard Brook is a Long-Term Ecological Research site where ongoing studies since the 1960’s investigate the impact of vegetation on hydrology and biogeochemistry in small watersheds.

What was the experimental treatment in Hubbard Brook’s study?

The treatment involved clearcutting all trees and vegetation in one watershed (W2) while leaving another (W6) as a control. Snow-covered was left undisturbed, and herbicides prevented regrowth for a few years.

What were the MAJOR findings of this experiment?

• Earlier snowmelt runoff in W2 compared to W6

• Streamflow increased by 40%, 28%, and 26% during the three years of deforestation

• Nitrate concentrations in stream water in W2 rose significantly, from <1mg/L to >50 mg/L within two years

What are patches in landscape ecology?

Patches are homogenous areas distinct from their surroundings in terms of size, shape, and composition.

How is “patchiness” measured?

Patchiness can be measured by assessing forest cover and patch shape, focusing on the distribution and characteristics of forested and deforested lands.

Define an ecotone and its significance?

 An ecotone is a transitional area between two ecosystems, supporting species from both ecosystems as well as unique species. It has higher species richness due to the "edge effect."

What are the ecological impacts of habitat fragmentation?

• Habitat fragmentation increases edges and patches, reducing habitat areas and causing:

  • Greater sunlight and wind exposure at edges.

  • Hotter, drier conditions.

  • Increased tree mortality and reduced forest canopy

What is the importance of interdisciplinary research in landscape ecology?

Interdisciplinary research integrates knowledge from multiple fields like biology, geology, and physics to better understand complex ecosystems.

How do spatial patterns affect ecological processes?

Spatial patterns determine the flow of energy, nutrients, and organisms, influencing ecosystem functionality across scales.

What role do watersheds play in ecosystem processes?

Watersheds channel water and nutrients, influencing local hydrology and biogeochemical cycles at regional and global scales.

How does the Chesapeake Bay Watershed impact its surrounding ecosystem?

The Chesapeake Bay Watershed affects water quality and nutrient cycles due to its extensive drainage area.

What was the purpose of using herbicides during the Hubbard Brook clearcutting experiment?

Herbicides were used to prevent vegetation regrowth temporarily, ensuring clearcut conditions to study long-term effects on hydrology and nutrient cycling.

 What conclusions were drawn about nitrate levels in the clearcut watershed?

 Deforestation caused a significant increase in nitrate leaching into streamwater, highlighting vegetation's role in nutrient retention.

Why is patch shape important in landscape ecology?

Patch shape affects edge length and interior habitat conditions, which can influence species distribution and ecological interactions.

How do patch size and composition influence biodiversity?

Larger, continuous patches support more species, while smaller, fragmented patches increase edge effects and may lead to biodiversity loss.

What are the primary drivers of edge effects?

Increased sunlight, wind exposure, and reduced moisture at edges alter microclimates, impacting species composition and survival.

How do edge effects extend over time in the Amazon Basin?

Edge effects have been shown to penetrate up to 1 km from the forest edge, doubling the area affected by deforestation between 1978 and 1988.

How do ecotones contribute to ecological diversity?

By supporting a mixture of species from adjacent ecosystems and unique species, ecotones enhance overall biodiversity.

What challenges do ecotones face due to human activities?

Habitat fragmentation and land-use changes disrupt ecotones, reducing their ability to support diverse species.

How can understanding watershed dynamics help in environmental management?

Insights from watershed studies guide sustainable water management, pollution control, and land-use planning.

Why is it essential to study biogeochemical cycles in deforested areas?

 It helps predict and mitigate the ecological impacts of land-use changes, like nutrient loss and soil acidification.

 What additional factors could be studied in the context of landscape ecology?

Future research could focus on climate change impacts, species migration patterns, and the restoration of fragmented habitats.

How might technology, such as remote sensing, enhance landscape ecology studies?

Remote sensing provides large-scale, detailed data on land cover changes, aiding in the analysis of ecological processes over time.

What is habitat heterogeneity, and what are its causes?

• Habitat heterogeneity refers to the diversity in habitat types within a landscape. Causes include:

  • Natural Factors: Fires, floods, and geological processes.

  • Anthropogenic Factors: Urbanization, deforestation, and agriculture.

  • Historical vs. Modern Context: Legacy effects from past disturbances, like fires in Yellowstone.

How do natural legacy effects impact landscapes?

Natural legacy effects, such as nutrient-rich soils after a fire, influence long-term ecological patterns and species distributions.

How does habitat fragmentation affect ecosystems?

• Fragmentation:

  • Reduces overall habitat area.

  • Increases the amount of edge habitat.

  • Leads to patch isolation.

What are the general characteristics of edge habitats?

• Edge habitats are:

  • More exposed to sunlight and wind.

  • Hotter and drier.

  • Prone to higher tree mortality.

  • Associated with decreased forest canopy and increased understory growth.

How did deforestation impact the Amazon Basin from 1978-1988?

 Deforestation increased edge effects, doubling the area affected due to the penetration of edge conditions up to 1 km from the forest edge.

What methods are used to measure patchiness in landscapes?

• Patchiness can be analyzed by examining:

  • Forest cover percentages across regions.

  • Patch shapes and their influence on edge-to-interior ratios.

Why is patch shape important?

 The shape of patches affects ecological interactions and the degree of edge effects, influencing habitat suitability for species.

What is a metapopulation?

A metapopulation consists of populations of a species distributed across separate patches, connected by occasional dispersal or migration.

What factors influence metapopulation dynamics?

• Patch size and isolation.

• Species dispersal abilities.

• Habitat quality within patches.

What were the findings of the spotted owl study (1987-1993)?

• The owl population decreased significantly, suggesting high extinction risk.

• Northern and Mexican spotted owls are listed as "threatened," while California spotted owls are considered "species of concern."

• Upgrading these owls' conservation status to "endangered" is under consideration.

What happened during the flooding of Lago Guri?

The flooding fragmented terrestrial habitats, creating "islands" of forested habitat. This isolation drastically affected species interactions and population dynamics.

What are the key consequences of deforestation in terms of edge effects and habitat fragmentation?

Deforestation reduces habitat area, increases the amount of edges and patches, and isolates patches of forest.

How do edge habitats differ from interior forest environments (e.g., exposure, temperature, and forest structure)?

Edge habitats have greater exposure to sunlight and wind, are hotter and drier, experience increased tree mortality, and have reduced forest canopy with increased understory vegetation.

What were the findings of the Skole and Tucker study (1993) on edge effects in the Amazon Basin?

The study assumed edge effects extended 1 km from the forest edge. From 1978–1988, the area affected by edge effects more than doubled.

How did the demographics of the spotted owl (1987–1993) illustrate the risks of habitat fragmentation?

The spotted owl population decreased during this period, showing that if the trend continued, the population faced a high risk of extinction.

What are the conservation statuses of the Northern, Mexican, and California spotted owls?

The Northern and Mexican spotted owls are listed as “threatened” under the Endangered Species Act (ESA), while the California spotted owl is listed as a “species of concern” in California.

What does the theory of island biogeography (IBG) study, and what predictions does it make about species richness?

IBG studies how islands or small habitat patches are colonized and how species richness changes over time. It predicts that larger islands will have greater species richness and will more closely resemble the mainland.

How do immigration and extinction rates influence species richness on islands?

Immigration rates are highest when an island is empty and decline over time. Extinction rates increase as species richness increases.

What is the equilibrium point in island biogeography, and how does it relate to species diversity?

The equilibrium point occurs where immigration and extinction rates intersect. It predicts the number of species an island can support over time.

How does IBG theory apply to metapopulation structures?

It suggests that the immigration and extinction rates of subpopulations within metapopulations should follow the same dynamics as those described in IBG theory.

What is the SLOSS debate in conservation biology?

SLOSS stands for "Single Large or Several Small" and debates whether it’s better to conserve a single large habitat or several smaller ones, depending on scale and species of concern.

What are the advantages of preserving a single large habitat versus several small ones?

Single large areas increase overall species richness for a particular habitat. Several small areas promote ecosystem variation and overall diversity.

What is the purpose of wildlife corridors in conservation?

Wildlife corridors connect fragmented habitats, helping to maintain population connectivity, reduce extinction risks, and enable recolonization of areas.

How do wildlife corridors help alleviate the impacts of habitat fragmentation?

They provide pathways for species movement, enabling genetic flow and population recovery for species in fragmented landscapes.

What role do Christmas Island red crabs play in their ecosystem, and how is a wildlife corridor important for their migration?

Red crabs are key detritivores in the rainforest, contributing to nutrient cycling. Wildlife corridors are critical for their migration from the rainforest to the ocean for reproduction.

Describe the importance of wildlife corridors like the one at Binghamton University.

Such corridors provide connectivity for local wildlife populations, supporting ecosystem health and enabling species to move between fragmented habitats.

What is biodiversity?

Biodiversity refers to "biological diversity" and includes genetic diversity, species diversity, and ecosystem diversity. It is dynamic, influenced by processes like mutations, natural selection, speciation, and extinction.

What are the three main levels of biodiversity?

• Genetic diversity: The total genetic information within all individuals of a population or species.

• Species diversity: Includes species richness (total species count) and species diversity (weighted by relative abundance).

• Ecosystem diversity: Diversity among communities and their abiotic environments, influencing ecosystem functions.

Why is biodiversity important for ecosystem function?

• Biodiversity increases productivity, such as net primary production (NPP), through:

  1. Resource use efficiency: Better use of sunlight, nutrients, and water.

  2. Facilitation: Certain species aid the growth of others.

  3. Sampling effects: A diverse ecosystem is more likely to include highly productive species.

Where is species richness the highest?

Species richness is generally highest in the tropics and decreases toward the poles.

How does geography affect biodiversity?

Areas with diverse geographical features (e.g., mountains) tend to have higher biodiversity compared to flat, featureless areas.

What are biodiversity hotspots?

Biodiversity hotspots are regions with exceptionally high species richness and endemism, making them priorities for conservation.

What is stability in ecological communities?

Stability is the ability of a community to resist changes in species diversity and richness. High species diversity provides a buffer against disturbances that could alter community structure.

How does biodiversity contribute to community stability?

Diverse communities are more resilient and can recover better from disturbances, maintaining ecosystem function.

How do wildlife corridors mitigate the impacts of habitat fragmentation?

Wildlife corridors connect fragmented habitats, enabling species to move between them, maintaining genetic diversity, reducing inbreeding, and supporting population recovery.

What challenges might wildlife corridors face in highly urbanized areas?

Challenges include land-use conflicts, infrastructure barriers (e.g., roads and buildings), human-wildlife interactions, and funding or political constraints for corridor creation and maintenance.

How is genetic diversity measured in a population?

Genetic diversity is measured by analyzing the frequency and variety of alleles (gene variants) within a population.

What is the Shannon-Weiner Diversity Index, and what does it calculate?

The Shannon-Weiner Diversity Index calculates species diversity by considering both species richness (total number of species) and relative abundance (evenness).

What processes contribute to the dynamic nature of biodiversity?

Processes include genetic mutations, genetic drift, natural selection, speciation, extinction, disturbances, and climate change.

What is the relationship between ecosystem function and species diversity?

Ecosystems with high species diversity often have greater productivity, resilience to disturbances, and efficient resource use.

What are the exceptions to higher species richness on land compared to water?

Wetlands and coral reefs are exceptions, as these aquatic ecosystems exhibit exceptionally high species richness.

Why do tropical regions generally have higher species richness compared to polar regions?

Tropical regions have favorable climates, consistent temperatures, and abundant resources that promote high rates of speciation and reduce extinction rates.

What are endemic species?

Endemic species are unique to specific geographical areas and are not found elsewhere.

How do endemic species differ from other species, and why are they significant in conservation biology?

Endemic species are unique to specific areas and not found elsewhere. They are critical to conservation because their loss means global extinction.

Where is species richness typically the highest?

Species richness is generally highest in tropical regions and decreases toward the poles. On land, biodiversity is generally greater than in water, except for areas like wetlands and coral reefs.

What are functional plant groups, and how do they relate to biodiversity and ecosystem productivity?

Functional plant groups are categorized based on traits like growth timing and energy allocation. Diverse plant groups optimize resource use, enhancing ecosystem productivity.

How do resource use efficiency, facilitation, and sampling effects contribute to increased NPP in diverse ecosystems?

Resource use efficiency allows better utilization of sunlight, nutrients, and water; facilitation occurs when certain species aid others' growth; and sampling effects ensure the presence of highly productive species in diverse ecosystems.

What is the energy–diversity hypothesis?

This hypothesis suggests that areas with higher energy availability (e.g., through temperature and solar radiation) can support more species. However, it remains untested.

How does biodiversity contribute to ecosystem stability?

High biodiversity provides buffers against disturbances, helps maintain community structure, and enhances resilience by resisting abrupt changes in species richness and diversity.

What historical factors have influenced deer population trends in New York?

Deer populations in New York initially declined due to overhunting and habitat loss. Recovery occurred through hunting regulations and increased edge habitats. However, overpopulation emerged due to the loss of major predators.

What are the predators?

They are wolves, mountain lions, and coyotes.

How does deer overpopulation affect forest understory?

Overpopulation reduces forest understory biomass and diversity, negatively impacting songbird and sapling communities. It provides advantages to invasive species as deer prefer grazing on native plants.

What impacts do deer have on soil characteristics at Binghamton University?

• Soil inside deer exclosures showed:

  • Lower pH

  • Higher soil moisture and organic matter

  • Higher electrical conductivity

  • Changes in microbial soil community structure, suggesting deer overpopulation homogenizes the soil abiotic environment and microbial diversity.

What management strategies could address deer overpopulation at Binghamton University?

While specific strategies aren't said, typical management options include controlled hunting, fencing, relocation, and habitat restoration.

What does the "Island Biogeography Theory" suggest about species richness and island characteristics?

• The theory predicts species richness depends on the balance of immigration and extinction rates:

  • Larger or closer islands to the mainland have higher immigration and lower extinction rates, leading to greater species richness.

What ecosystem changes were observed in the Binghamton University deer research?

Overabundant deer altered the forest ecosystem by affecting soil characteristics, reducing tree regeneration (saplings), and impacting the overall structure of forest communities.

How are invasive species affected by deer overpopulation?

Deer overpopulation provides advantages to invasive species since deer preferentially graze on native plants, allowing invasive species to thrive and alter ecosystem dynamics.

What are the ecological problems caused by deer overpopulation?

• Increased vehicle collisions: Over 70,000 accidents yearly in the U.S., with 270 human deaths in 2013.

• Agricultural damage: $59 million in crop loss in 2002.

• Rising cases of tick-borne diseases like Lyme disease, as deer serve as a primary food source for adult ticks.

• Overbrowsing damages forest understories, reducing biodiversity and facilitating invasive species growth.

What evidence exists of deer overpopulation's impact on Binghamton University’s campus?

• Forest Changes: A reduction in native plant diversity, songbird nesting sites, and saplings for tree regeneration.

• Wildflower Loss: 12 species disappeared since 1995.

• Tree Age Structure: All tree seedlings and saplings are older, indicating no new regeneration.

What are common management strategies for controlling deer overpopulation?

• Physical barriers: Fencing to prevent grazing.

• Behavior modification: Using repellents (chemical or physical).

• Population control: Fertility control, regulated hunting.

Vegetation management: Replacing ornamental plants with less palatable

Why is managing deer overpopulation challenging?

• Ethical concerns and public opposition to hunting or fertility controls.

• Costs associated with fencing and repellents.

• Deer adaptability and their desensitization to human activity.

What is a “browse line,” and what does it signify?

A browse line is the visible line on trees where deer have eaten all reachable foliage. It signifies overbrowsing, leading to degraded forest structure and loss of understory vegetation.

How does deer overpopulation relate to invasive species?

Deer prefer grazing on native plants, giving invasive species an advantage, which can outcompete and further reduce biodiversity in affected ecosystems.