Environment and Biodiversity

Biodiversity is something that surrounds us all. It is the variety of life on earth that relies on other organisms and the physical environment. Today, scientists study biodiversity and how organisms interact with their environment to gain an understanding of how life evolves.

Environment and biodiversity definitions

The word biodiversity is derived from the phrase biological diversity. It refers to the variability among living organisms - within species, between species and within ecosystems. Scientists only started using the term at the start of the 20th century. Below is a standard definition:

Fig. 1 – Coral reefs are biodiverse habitats; they have a large variety of living organisms. Source: unsplash.com

So what about the environment?

Difference between environment and biodiversity

Often the words ‘environment’, ‘ecosystem’ and ‘surroundings’ are used interchangeably, however, they are slightly different.

Different types of biodiversity

There are different levels of biodiversity (species and ecosystem diversity). These are detailed below.

Species Diversity

Species biodiversity refers to the number of different species within an ecosystem as well as the relative abundance of each one of those species. There are two types of species diversity: within a species and between species. Intraspecies diversity refers to diversity among individuals in the same species and interspecies diversity refers to diversity between different species.

Ecosystem diversity

Our planet has many different ecosystems within it all of which have different species and habitats. For example, there are forests, mountains, deserts, etc. The variation and diversity among them is known as ecosystem biodiversity. An ecosystem consists of all the organisms and the physical environment, including abiotic and biotic conditions with which they interact.

Interaction of ecosystems

All ecosystems are interconnected and this interaction can occur between organisms and themselves as well as between organisms and their environment. Biodiversity is also important because ecosystems interact with each other. Living organisms regulate:

Atmospheric composition

Until around 2.4 billion years ago, there was no oxygen in the atmosphere. The abundance of life on earth is due to a drastic increase in oxygen levels. The main reason for higher oxygen levels is the fact that plants use carbon dioxide from the atmosphere and then release oxygen.

Biogeochemical cycles

Biogeochemical cycles are the way in which elements are used and recycled in the biosphere. A way that living organisms interact with biogeochemical cycles is through resource consumption.

Interspecies relationships

Some organisms provide a service to other organisms while others are negatively affected by other organisms.

Soil maintenance

Soil nutrient content is maintained by processes such as nitrogen fixation and vegetation cover helps to prevent the erosion of soil.

Genetic diversity

Genetic diversity is the total variety of genes in a species and how they are expressed.

Why is biodiversity important?

Biodiversity maintains the stability of ecosystems. Each species is of value to the ecosystem and different species depend on each other. Every organism has a role to play. If one species disappears then the environment and food chains for all other species can change. Biodiversity is also important for humans who use ecosystems as resources for foods, medicines, and tourism.

Food chains and food webs

A food chain portrays the feeding relationships between specific organisms. Arrows show the transfer of energy in stages called trophic levels. Food chains always start with a producer. A primary consumer then eats the producer. The primary consumer is eaten by a secondary consumer, which can be potentially eaten by a tertiary consumer. Animals consumed are predators and those hunted and eaten are prey. The consumer at the top of the food chain is called an apex predator and isn’t typically eaten by anything else.

Food webs are made up of many food chains which are interlinked. This is a better representation of how the organisms interact in the real world because most populations have more than one food source. They may prey on more than one organism at the trophic level.

Table 1. Biodiversity services and their examples.

Biomimetics

The term biomimetics stems from the ancient Greek words bios and mimesis, meaning “imitate”. It is a concept that draws inspiration from nature to solve complex human problems. Some uses are:

Genetics

New genes to improve crop genetics characteristics may be discovered. This can be seen in the genetically modified crops we have today. For example, sugarcane with a higher sucrose content.

Materials

Materials such as airbags, velcro, and body armour have been created that mimic the properties of some natural materials.

Fig. 4 – Biomimicry of Burr to make velcro. Source: unsplash.com

Adhesion

Lotus flowers have water-repelling properties which have been used to develop self-cleaning glass.

Building design

Termite mounds are above ground which creates convection currents. This concept has been used in architecture.

Vehicle design

The splayed wingtip feathers of soaring birds reduce wind turbulence so aircraft wing designs have been copied to help increase fuel efficiency.

Physiological research

We can study physiology through other organisms such as:

• Squids

Studying squids has enabled us to gain more insight into heart, kidney, and Alzheimer's disease as well as strokes and cancer. This is because their nerve cells are bigger than human nerve cells making them easier to study.

• Dolphins and bats

Both these organisms use high-frequency sound to source their food. The study of this mechanism has enabled the development of new and better ultrasound scanners.

• Purple sea urchin embryos

Female purple sea urchins produce extremely large quantities of eggs. They can be used when testing if medicines cause abnormal embryo development in humans.

• Marine sponges

They produce proteins that prevent rejection after transplant surgeries.

Distribution of biodiversity

Biodiversity is everywhere - from unicellular organisms to entire ecosystems. So what are some of the patterns we can observe?

Spatial patterns of biodiversity

This refers to the arrangement of individuals in space as well as their geographical relationships.

The distribution of biodiversity depends on:

• Climate

• Geography

• Soil

• Human activities

We can observe a lateral gradient in species diversity because there are fewer species in the higher latitudes and more species in the lower latitudes. Tropical areas tend towards higher biodiversity (due to higher temperatures and more fertile ground) and polar regions towards lower biodiversity. Areas with more human populations have less biodiversity as they tend to be more built up and urbanised. The exponential growth of the human population creates a greater demand for the earth’s natural resources such as food, water and materials.

Temporal patterns of biodiversity

Temporal biodiversity refers to the seasonal changes in biodiversity. Researchers study temporal patterns of biodiversity in order to better estimate the extinction of species. Despite this, long-term records are required for this and there are often lags observed in terms of ecological response to changes in ecosystems making predictions hard.

For example, Cameia National Par, Angola is a seasonally flooded savanna. The species composition and land use by living beings are controlled by seasonal floods, precipitation patterns and fires. This is because different organisms are adapted to different conditions and habitats.

Threats to biodiversity

Most of the threats to biodiversity stem from human activity.

Table 2. Threats to biodiversity.

Environment and biodiversity conservation

Scientists have developed many ways to conserve biodiversity and stop its decline. Here are some of them.

Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)

The Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act) commenced on the 16th of July 2000. It is a major piece of environmental legislation in Australia and provides the legal means to protect areas of national environmental significance.

The Wildlife and Countryside Act 1981

This is the primary legislation, which protects animals, plants and habitats in the UK.

The act contains four parts, which cover:

• Part 1: Wildlife

• Part 2: Nature conservation, the countryside and National Parks.

• Part 3: Public rights of way.

• Part 4: Miscellaneous provisions of the act.

The IUCN - International Union for Conservation of Nature

The IUCN helps to identify species that should be prioritised for conservation. Its specific roles are to coordinate label data on biodiversity conservation, increase understanding and deploy nature-based solutions.

It categorises organisms as:

• extinct (EX)

• extinct in the wild (EW)

• critically endangered (CR)

• endangered (EN),

• vulnerable (VU)

• near threatened (NT)

• least concern (LC)

Specific characteristics that may identify a species as one that should be prioritised include:

• Flagship species

• Keystone species

• Endemic species

• High level of threat to habitat

• Dispersed population

• Evolutionary distinct species

The roles of the IUCN:

• Coordinating global data on biodiversity conservation

• Increasing understanding of the importance of biodiversity

• Deploying nature-based solutions to global challenges in climate, food and sustainable

• development.

There are also:

EU CFP - common fisheries policy of the european union

This aims to make fishing and agriculture environmentally, economically and socially sustainable. Some ways that this is implemented is through:

• Catch quotas (to limit the amount of fish certain vessels can catch)

• Net mesh regulations (prevents smaller, younger fish being caught so they can breed)

• Limits on fishing

• Bans on discarding of unwanted fish

ITTO - international tropical timber organisation

This aims to encourage sustainable management of forests.

In the UK:

SSI's - sites of special scientific interest

NNR's - national nature reserves

In the EU:

SAC's - special areas of conservation

SPA's - special protection areas (protection of birds).

LNR'S - local nature reserves

MNR'S - marine nature reserves.

ramsar sites - protection of wetlands

AONB's - areas of outstanding natural beauty

NP's - national parks

There are also environmental stewardship schemes that landowners and farmers can be part of.

ELS - entry level stewardship

(open to all farmers and landowners, simple and effective land management).

OELS - organic entry level stewardship

HLS - higher level stewardship (targeted environmental management).

Some environmental stewardship scheme examples include:

• Beetle banks (a strip planted within a crop field, that provides habitats for species that prey on pests).

• Buffer strips (reduce water pollution)

• Field margins (allow nesting).

• Hedges (provide habitats for many species).