Peak biodiversity on land

1. It gets worse before it gets better
2. Habitats and forests destroyed
3. Plagues — the pests we’ve spread everywhere
4. Predators — the ‘ecosystem police’ we’ve hunted to near extinction
5. Peak biodiversity: some truly frightening statistics

1. It gets worse before it gets better

I promise we’ll look at some of the things being done to repair ecosystems and some of the strategies to save species and parks and ecosystems — the stuff you can get involved with. But I have to admit, the following few pages are pretty grim stuff. This page will look at the loss of species and life on land. The oceans are so grim that I devoted a page to them. Then we look at how individual species loss can impact on a whole ecosystem, and the sheer economic value of those ecosystem services. Then we’ll browse through some of the scientific reports that have been warning us for the last few decades and finally ask what we can do to show that we’ve heard them. Without further delay, let’s look at some of the factors destroying life and ecosystems on our continents.

2. Habitats and forests destroyed

Peak wood affected Europe centuries ago. The hunt for wood was one of the driving historical forces that sent the British empire expanding outwards into the New World in the search of timber to build the empire’s navies and fuel the fires of new industries. Demand for timber now means that by 2030 only 10% of our world’s forests will remain. Forests are important as a resource for wood, but rainforests also generate rain, and forests are habitat for many important species and fungi and micro-organisms and birds and mammals across the whole range of biodiversity. They are the only home for hundreds of thousands of different critters, and we need them all to maintain biodiversity.

Deforestation occurs for many reasons. Logging old growth forests is an economic opportunity for poorer nations that might not have access to cheap industrial means of planting forestry management. Slash and burn agriculture, pasturelands, alternative crops and other farming requirements also cut down many forests. As the wiki says:-

The removal of trees without sufficient reforestation has resulted in habitat damage, biodiversity loss, and aridity. It has adverse impacts on biosequestration of atmospheric carbon dioxide. Deforestation has also been used in war to deprive the enemy of vital resources and cover for its forces. Modern examples of this were the use of Agent Orange by the British military in Malaya during the Malayan Emergency and the United States military in Vietnam during the Vietnam War. As of 2005, net deforestation rates have ceased to increase in countries with a per capita GDP of at least US$4,600. Deforested regions typically incur significant adverse soil erosion and frequently degrade into wasteland.

Disregard of ascribed value, lax forest management, and deficient environmental laws are some of the factors that allow deforestation to occur on a large scale. In many countries, deforestation – both naturally occurring and human-induced – is an ongoing issue. Deforestation causes extinction, changes to climatic conditions, desertification, and displacement of populations as observed by current conditions and in the past through the fossil record. More than half of all plant and land animal species in the world live in tropical forests.

Between 2000 and 2012, 2.3 million square kilometres (890,000 sq mi) of forests around the world were cut down. As a result of deforestation, only 6.2 million square kilometres remain of the original 16 million square kilometres of forest that formerly covered the Earth. An area the size of a soccer football pitch is cleared from the Amazon rainforest every minute, with 136 million acres of rainforest cleared for animal agriculture overall.

3. Plagues — the pests we’ve spread everywhere

As Strange Days on Planet Earth so clearly showed, everywhere we trade goods and services, we introduce invaders. We bring a walking, jumping, leaping, spreading, blowing, swimming, tumbling plague of every beast and pest and insect and weed with us. We have nearly destroyed Australia by introducing rabbits, foxes, pigs, camels, cats, feral dogs, weeds, fish, and of course the cane toad! The more pests we introduce, the weaker the local ecosystem. By the sheer force of our frequent movements, we are creating the one global ecosystem, and the risks of precious local ecosystem services fighting it out to the death are just horrific.

4. Predators — the ‘ecosystem police’ we’ve hunted to near extinction

The Eclipse summary page mentioned that we could soon see a world without large predators like lions and tigers and bears in the wild. Top line predators are like the police force of ecosystems. They regulate the ecosystem, and stop otherwise harmless members of the food web breeding out of control and destroying the place. As journalist George Monbiot describes it, “a ‘trophic cascade’ is an ecological process which starts at the top of the food chain, and tumbles all the way down to the bottom.”  It’s just under 5 minutes, and is a beautifully shot and clearly explained masterpiece.

For more detail please see the National Geographic special Strange Days on Planet Earth, which describes how after we hunted down the last wolf, park erosion accelerated, the river silted up, the beavers left and the river started to bend and move all over the place. We removed the ‘police’, and the ecosystem ran amok. (Watch the hour long Youtube docuentary or read the text summary here.)

5. Peak biodiversity: some truly frightening statistics

The sneaky thing about the damage to life on earth is that this contest is being lost in ten thousand small local battles rather than one big war. This is both the horror and the hope of the ecological challenge. The sheer magnitude of destruction across our world is terrible, but there is hope in the local environmental battles to save local parks, wetlands, forests, frogs, and everything else.

As the International Union for the Conservation of Nature reports:

• 17,291 species out of 47,677 so far assessed are threatened with extinction.
• Of the world’s 5,490 mammals, 79 are Extinct or Extinct in the Wild, with 188 Critically Endangered, 449 Endangered and 505 Vulnerable.
• 1,895 of the planet’s 6,285 amphibians are in danger of extinction, making them the most threatened group of species known to date.
• More than 70,000 plant species are used in traditional and modern medicine.
• Coral reefs provide food, storm protection, jobs, recreation and other income sources for more than 500 million people worldwide yet 70% of coral reefs are threatened or destroyed.
• Biodiversity is essential to global food security and nutrition and also serves as a safety net to poor households during times of crisis.
• Diversity of genes within species, e.g. as represented by livestock breeds or strains of plants, is also important for agriculture and food security. Increased diversity reduces risk from diseases and increases our potential to adapt to changing climate.

 

Please read on to Peak Ecosystem Services, where we learn that even the World Health Organisation are concerned about Biodiversity loss and the impact on humans!