C.4 Conservation of biodiversity Flashcards
What are indicator species?
A species used to assess a specific environmental condition
Why do indicator species have a limited range of tolerance?
As they are sensitive to specific environmental cconditions
Why are indicator species populations a useful mean of monitoring change?
Their population growth or reduction indicates changes in the environment
What are lichen susceptible to?
Airborne pollutants dissolved in water
What are tubifex worms sensitive to?
Concentrations of heavy metals
What are mayfly larva sensitive to?
Dissolved oxygen levels in water
What do biotic indices compare?
The relative frequency of indicator species?
What do biotic indices provide?
An overall assessment of environmental health
How do you calculate a biotic index?
(population size of indicator species x tolerance rating of species) / total number of individuals collected
What does a high biotic index indicate?
The presence of many pollution sensitive organisms and an unpolluted environment
What does a low biotic index indicate?
A polluted environment due to an abundance of pollution tolerant organisms
What does a change in the biotic index over time suggest?
A change in the environmental conditions within a given ecosystem
What is biodiversity?
The variety and variability of all living organisms in a given ecological area
What can biodiversity be used to refer to? (3)
Number of species
Genetic diversity
Habitat variety
What are the two main components that contribute to biodiversity?
Species richness and species eveness
What is species richness?
The number of different species present in an area
What is species evenness?
The relative abundance of the different species in an area
What does more species mean in terms of richness?
More richness
What does similar abundance mean in terms of eveness?
More evenness
What can the simpson’s reciprocal index be used to measure?
The relative biodiversity of a given community
What does the simpsons reciprocal index take into account?
The species richness and eveness
What is a high simpsons reciprocal index value indicative of?
A stable site with many different niches and low community
High richness and eveness
What does a low simpson’s reciprocal index value indicate?
A site with few potential niches where only a few species dominate
Low richness and eveness
When may the simpson reciprocal index value change?
In response to an ecological disturbance
What promotes biodiversity better, smaller or larger habitats?
Larger habitats
Why do larger habitats promote biodiversity better than smaller habitats?
More available niches = less competition
Why do edges of habitats have better biodiversity?
As different habitats with different abiotic factors live in close physical proximity
What is the edge effect?
The diversity of species within a given environmental changes with proximity to the ecosystems boundaries
What has more competition, edges or central regions?
Edges
What does the competition in edge habitats restrict?
The survival prospects of certain species
What can improve genetic diversity in fragmented habitats?
Habitat corridors
What do habitat corridors do?
Connect disparate regions
What are the three ways nature reserve habitats are improved for the concentration of biodiversity?
Larger is better
Less edge is better
Clustered reserves are better
What is the biodiversity of an island typically proportionate to?
Island size
What do larger islands support and why is that important?
Support a greater range of habitats creating more niches for species to occupy
What can larger islands sustain and what does that increase?
Higher population numbers per species increasing species evenness
What do larger islands have greater productivity at and what does it lead to?
Each trophic level leading to longer, more stable food chains
Why may biodiversity be greater at the border between two species?
Different abiotic factors favour certain species
If a species cannot thrive at an edge environment where will it be?
In the central regions
What will the effect of edges on biodiversity be influenced by?
Particular conditions caused by the ecological disturbance
What is conservation?
The maintenance and protection of natural resources
What are the two types of conservation?
In situ and ex situ
What is in situ conservation?
The preservation of plant and animal species within their natural habitat
What is the typical examples of in situ conservation
Nature reserves and natural parks
Why may in situ conservation need active management?
To ensure an appropriate and sustainable ecological balance is maintained
Why may ecological monitoring of species be required in in situ conservation?
To ensure viable population levels are maintained
Why may interventions be required in in situ conservation?
To prevent habitat degradation or competition from invasive species
Why may legislation be necessary in in situ conservation?
To ensure funding for policing and education
What are the main advantages to in situ conservation?
- allows species to live in natural environment
- maintains animals normal behaviour
- protects natural habitat from loss
- provides a place for breeding programs
- provides a place for scientific study and education
Where do offspring aquire skills from?
From parents and peers around them
Why are in situ conservations good for breeding programs?
They provide realistic conditions for reintegration
Why is it important to retain the natural habitat for in situ conservation?
So it remains available for other endangered species
What is ex situ conservation?
The preservation of plant and animal species outside their natural habitats
When is ex situ typically required?
For critically endangered species when urgent intervention is required
What are the main advantages of ex situ conservation?
- allows for more control of essential conditions
- improves chances of successful breeding via artificial methods
What are the associated disadvantages of ex situ conservation?
- do not prevent potential destruction of natural habitats
- species raised in captivity are less likely to be successful in the wild
- increases inbreeding by restricting gene pool
What are three examples of ex situ conservation?
Captive breeding
Botanical gardens
Seed banks
What is captive breeding?
Animals are raised and bred in containment to ensure survival prospects
What are botanical gardens?
Areas devoted to the collection, cultivation and display of a wide variety of plant species
What are seed banks?
Secure sites that store and catalogue seeds in order to preserve plant genetic diversity
How many indian rhinoceros are there in the wild?
3500
Why has the number of indian rhinos increased from 2000 since the 1990s?
Successful captive breeding programs
What are the indian rhinos main threats?
Habitat loss and poachers
Where are the majority of indian rhinos?
In indian protected areas
Where is the mountain chicken frog native to?
Carribean islands
By how much has the population of the mountain chicken frog declined?
81%
Why has the population of the mountain chicken frog decreased?
Due to the fungal disease chytridiomycosis
Apart from fungal disease what is another threat to the mountain chicken frog?
Human consumption
How many mountain chicken frog are in the wild?
8000
What is the mountain chicken frog classified as?
Critically endangered
What attempts to save the mountain chicken frog have been made?
They have been artificially bred in labs in england before being reintroduced to the wild
