Evaluating Biodiversity and Vulnerability

Identifying factors that lead to loss of diversity

Main five pressures on biodiversity are still present and even intensifying:

1. Habitat loss and degradation
2. Climate change
3. Excessive nutrients and other pollutants
4. Over-exploitation and unsustainable use of resources
5. Invasive alien species

There is something known as the Red List that shows the status of species in terms of their conservation status. You can see the list here.

It should be mentioned that biodiversity conservation is crucial. Biodiversity, be it genetic, habitat, or species, is one of the determining factors in an ecosystem's health. The above mentioned factors are putting pressures on the planet that it cannot absorb fast enough. Ecological footprints are exceeding the Earth's capacity to recover. All of this leads to a persistent loss in biodiversity that slowly reduces our ecosystems' resilience and compromises the resources on which we depend.

There are certain world trends that are occurring around the world:
- Habitats are declining.
- Abundance and distribution of species are declining.
- Change in status of threatened species.
- Threats in genetic diversity in domestic animals, cultivated plants, and fish species. This is due to interference with natural selection.
- Coverage of protected areas are increasing
- Marine Trophic Index has shown an increase, but has regional fluctuations.
- Ecosystems have become more fragmented.
- Water quality in aquatic ecosystems has been declining. Some areas have increased their water quality by dealing with point-source pollution.
- Nitrogen deposition has increased.
- The amount of invasive species has increased and are now a threat.
- Areas of forest, agricultural, and aquaculture ecosystems under sustainable management have increased, but there are several areas that still require more efforts.
- Humanity's Ecological Footprint is still rising.

Policies and their Effect on Human Population

The objective of this activity is to discuss how international and national development policies and cultural influences can affect human population development and growth.

The following outline presents a comparison between the countries of Australia and United Kingdom in terms of sustainability policies and the effect on their respective populations.

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Australia
Population facts

• Ageing population (Baby boomers are growing old)
• High levels of immigration into the country
• Consistent growth, but uneven across the different regions
• Great majority of population lives in urbanized areas

Aims

• Economic stability
• Address labor shortages
• Prepare accordingly for when the population pyramid finally inverts
• Sustainability across the country
• Improve connections between regions
• Improve infrastructure
• Increase food production without compromising the environment
  

Policies

• Immigrants on work visas will face a much more simplified process.
• Infrastructure development projects will focus on those areas that present the most growth.
• Economic policies are working to strengthen connections with international companies.
• Agricultural policies are working to increase food production, but limiting the amount of additional resources that are used. (Target: Low input, high yield)
• Working to relocate people in order to limit the growth of urbanized areas so as to protect biodiversity and avoid the habitat degradation and loss.

United Kingdom
Population facts

• Aging population (Baby boomers)
• Growing population
• Population divided by regions
• There is a certain level of immigration

Aims

• Control population growth
• Manage population segments before the population pyramid inverts
• Protect natural resources
• Achieve high employment levels
  
• Sustainability through education
  

Policies

• Government support will help provide jobs and training.
• Prevent emigration by creating communities where people will want to live and work.
• Provide family planning services
• Work toward social inclusion of all citizens
• Focusing on education and sustainability through educating the population
• Work together with international organization to determine sustainability policies
• Health care available to increase the population's well-being.
  

Conclusions
It can be seen in both cases, the policies are made according to the population conditions. This means that policies issued are based on the needs identified in a specific population. At the same time, the policies have an effect on the people, so it goes both ways. For example, Australia has a high immigration rate and the growth of its own population is constant but not enough to cause significant problems. This is why Australia focuses on taking advantage of immigration to target labor shortages which will become an increasing problem as the population ages. United Kingdom also has an aging population, but it is focusing more on retaining its current population and training them to address the labor shortages.

Both countries are focusing on achieving sustainability, but each of the policies are made considering the culture, geography, and needs of each country's population.

Limiting Factors and Population Growth

Populations can change over time due to many different variables, known as limiting factors. These keep populations in check and can be classified into

• Density dependent factors
• Density independent factors

Density dependent factors are those that, as its name implies, depend on population density. This means that the impact these factors have depends on how many individuals there are. These are usually biotic factors, such as biomass, predation, competition.

Density independent factors are those that affect a population regardless of its size. These are usually abiotic factors. Some examples are pH, temperature, salinity, and also natural disasters such as tornadoes, earthquakes, volcanic explosions.

GROWTH CURVES

Growth rate can be graphed. There are two different types of curves:

• J-curve
• S-curve

Each shows a different type of population growth.

J-curves show exponential growth. The population grows exponentially and then crashes or suffers what is known as a dieback. This is because the population overshoots and exceeds the carrying capacity (K), which is the maximum amount of individuals an ecosystem can support without being affected. This is known as a boom and bust pattern. This growth rate is common in organisms.

S-curves start out as exponential growth, but then stabilize as the population reaches its carrying capacity. This growth rate is consistent with density dependent factors. This is known as a logistic curve.

S- and J-curves are idealized. In nature, both types of limiting factors act on the same population and the result is a combination of both curves.

And what about humans?

Human population seems to be growing exponentially, but in my opinion, seeing the conditions our planet is in, it seems as if we have surpassed our carrying capacity. Is the human population heading for a dieback? How much longer before the population crashes?

Sustainability is....

• Recognizing that you form part of a system, and that your actions have an impact on whether or not you can carry on with that way of life.
• Using only what you need.
• Using resources responsibly.
  
• Respecting nature, not abusing it.
• Meeting your needs without harming nature.
• Living in such a way that you ensure that life will carry on and that quality of life will be maintained.
• Being able to maintain your living conditions because of the fact that the environment is not being abused, and thus can keep providing the necessary resources.
• Making sure that future generations will have a world to live in and care for.
  
• Teaching future generations what it means to form part of an ecosystem.

This and many more things define sustainability. Sustainability is not a simple concept that can be defined in two or three sentences. It is a way of life. It is something that should be applied in all aspects of life. It should be a way of measuring our actions.