Caretakers versus Exploiters: Impacting Biodiversity in the Age of Humans

Unit Content

“We should preserve every scrap of biodiversity as priceless while we learn to use it and come to understand what it means to humanity.”-E. O. Wilson²

Can you recall and describe your favorite childhood place in nature? Where was it, how did you find it, how did you feel when you were there, what became of it? When introducing students to nature, where is the balance between imparting information and encouraging joy and wonder? What role should nature experiences play in education? These are questions we must ask ourselves when preparing lessons for our students, lessons that will keep them engaged, spark wonder in their young minds, and possibly encourage the beginning of a great love in their lives.

Isabella Tree so perfectly explains that “Children who spent time in green spaces between the ages of seven and twelve tend to think of nature as magical. As adults they are the people most likely to be indignant about lack of nature protection, while those who have had no such experience tend to regard nature as hostile or irrelevant and are indifferent to its loss. By expurgating nature from children's lives, we are depriving the environment of its champions for the future.”³  

Biodiversity

So, what is biodiversity and why is it important? Biodiversity is the all the variety of life that can be found on Earth (plants, animals, fungi and micro-organisms) as well as to the communities that they form and the habitats in which they live. It is where life interplays with the physical environment. Looking at it in a philosophical way, biodiversity is the knowledge learned by evolving species over billions of years, about how to survive in the face of environmental changes. Below are two examples of biodiversity: Figure 1 shows the polar region and Figure 2 shows an ocean habitat illustrated by a student.

So why does it matter? The air you breathe, water you drink, and food you eat all rely on biodiversity. It is also used as a way to measure the health of biological systems, and to see if there is a danger that too many species may become extinct. Coral reefs and mangrove swamps protect coastal regions from cyclones and Tsunamis, trees can absorb air pollution in urban areas, many reptiles and mammals disperse seeds to maintain forests. The study of ecosystems reveals countless such interactions, which foster sustainability of our living planet. ⁶ There is also the human benefit in biodiversity as it provides sources of medicines for us.

Problems with Biodiversity

The problem we are facing now is that biodiversity is being threatened as a result of human activities and from the effects of global warming to our planet. The main dangers to biodiversity worldwide are population growth of humans and resource consumption, over-hunting, climate change and global warming, habitat conversion and urbanization, invasive alien species, over-exploitation of natural resources and environmental degradation or pollution. This bring us to the term Anthropocene, which is the current geological age, a period when human activity has been the dominant influence on climate change and the environment. 75% of land and 66% of marine environments are significantly altered by humans. Over 1/3 land and ¾ freshwater is now used for livestock and to produce crops. Up to 300 million people are at an increased risk of floods and hurricanes due to loss of coastal habitats and protection. 33% of marine fish stocks are being harvested at unsustainable levels. Urban areas have more than doubled since 1992, plastic pollution increased ten-fold since 1980. Up to 400 million tons of heavy metals, solvents, toxic sludge and other industrial wastes are dumped annually into the world’s waters.⁷ Natural processes also effect biodiversity, such as wind, rain, earthquakes, and the preying of one animal on others.

Climate Change and Biodiversity

In regard to the effects of climate change and biodiversity is a long list of unfortunate truths. Many species won’t be able to adapt quickly enough to changes in their environment. The earlier arrival of Spring changes the life cycle of many plants that provide food and habitat for other species. When this happens, other problems could occur with other species like when the lifecycles of dependent species change and no longer matchup, such as a migrating species arrives at a habitat after their prey has already passed. Habitat fragmentation is also a problem, this happens when natural landscapes are broken up by developments by humans such as river dams and highways, which can interrupt migration routes. Higher temperatures in atmospheres could cause longer growing seasons for forests.

Climate change causes harmful algae growth in marine ecosystems, which are also at risk of pollution and commercial fishing. Many northern ecosystems are vulnerable to habitat loss and could see an influx of new species and diseases from the south. This brings us to the topic of invading species of ecosystems. Invasive Species are plants and animals that are not native to a particular area. Not only are these species introduced to foreign environments because of climate change which could cause their main food source to disappear and force them to search other places, but they are also introduced to the foreign environments by the travel of humans. When people travel by airplane, and by large ships that contribute to invasive aquatic species. Invasive species may compete with native species for resources, such as food, and have no natural predators to restrict their ability to breed and thrive. Invasive species may force out or cause native species to become extinct. The interesting fact about invasive species, is that once they are established in the new community it can be difficult or even more damaging to remove them.

Negative Effects of Humans on Biodiversity

“I sought a career in herpetology because I enjoy working with animals,” Joseph Mendelson, a herpetologist at Zoo Atlanta, has written. “I did not anticipate that it would come to resemble paleontology.” -Elizabeth Kolbert⁸

“The line between natural and human caused effects often blurs. For example, sediment in streams and rivers can damage these tender ecosystems. But the cause may have been a post-storm mudslide or acreage stripped bare for farming. Anything that enters an ecosystem – from sunlight to rain to contaminants – has the potential to change it. Scientists refer to these factors as drivers.”⁹ Consequently, the number of endangered species is growing by the day. According to the International Union for Conservation of Nature (IUCN) as of July 9,2020 more than 27,000 species are threatened with extinction. We as humans have become dependent on luxuries such as cars, houses, and even our cell phones. But what does our love for manufactured metallic and plastic goods do to the environment? Human activity can be directly attributed to the cause of hundreds of extinctions in the last two centuries, versus the millions of years that extinctions naturally occur. As we progress through the 21st century, humans have changed the world in unprecedented ways.

New York Times Bestseller Elizabeth Kolbert writes in her book The Sixth Extinction,

Today, amphibians enjoy the dubious distinction of being the world’s most endangered class of animals; it’s been calculated that the group’s extinction rate could be as much as forty-five thousand times higher than the background rate. But extinction rates among many other groups are approaching amphibian levels. It is estimated that one-third of all reef-building corals, a third of all freshwater mollusks, a third of sharks and rays, a quarter of all mammals, a fifth of all reptiles, and a sixth of all birds are headed toward oblivion.”¹⁰

This brings us to the concern biologists have for many of today's species. While the number of actual documented extinctions may not seem that high, they know that many more species have little hope of survival because of their interrelationships -- for example, the loss of a pollinator can doom the plant it pollinates, and a prey species can take its predator with it into extinction.

Positive Effects of Humans on Biodiversity

“Humanity can no longer stand by in silence while our wildlife are being used, abused and exploited. It is time we all stand together, to be the voice of the voiceless before it's too late. Extinction means forever.” -Paul Oxton

Indigenous people understood the importance of being one with nature and respecting it as it literally gives us life. I feel it is imperative to seek their knowledge and adopt their ways as a society to ensure our children and their children have a green and healthy place to call home. Not all things humans do are harmful or threatening to biodiversity. There are many people who practice the three r’s Reduce, Reuse, and Recycle to do their part in saving the planet.

Fortunately, there are also many organizations that are committed to preserving it and creating laws, movements and days annually that are dedicated to fundraising, bringing awareness to the issues and active clean up or the building of sanctuaries or wildlife preserves that serve the purpose of keeping earth’s wildlife and biodiversity alive! A few of them include: National Parks Conservation Association, Wildlands Network, Endangered Species Coalition, Defenders of Wildlife, and The E.O. Wilson Biodiversity Foundation. There are inventors who are creating machines to clean up the ocean and fix the devastation that is water pollution. In recent years, many states and local communities created laws that require building developers to set aside Green and Open Spaces of land to protect the local wildlife.

So, we must decide, which side of the history of biodiversity will we be on? What will we teach our students to value? Will we encourage them to be “exploiters” of our earth or “caretakers” of it?

History of National Parks

"We have fallen heirs to the most glorious heritage a people ever received, and each one must do his part if we wish to show that the nation is worthy of its good fortune."-Theodore Roosevelt¹¹

Perhaps one of the greatest positive effects that humans have had in our history, is the establishment of national parks. The conservation legacy of Theodore Roosevelt, who is also known as the “conservationist president”, is found in the 230 million acres of public lands he helped establish during his presidency. Much of that land - 150 million acres - was set aside as national forests. The idea was to conserve forests for continued use. An adamant proponent of utilizing the country's resources, Roosevelt wanted to insure the sustainability of those resources.

Years later, The National Park Service Organic Act established the National Park Service. The Act was signed into law on August 25, 1916, by then President Woodrow Wilson.

The purpose of this act was to promote and regulate the use of the Federal areas known as national parks, monuments, and reservations, whose purposes were to conserve the scenery, the natural and historic objects, and the wildlife to provide enjoyment of future generations.

Then, on June 11, 1933, President Franklin D. Roosevelt signed Executive Order 6166 which consolidated all National Parks and National Monuments, National Military Parks, the eleven National Cemeteries, National Memorials, and the National Capital Parks into a single National Park System. The National Park Service was directed to oversee all of these areas. Since 1872 the United States National Park System has grown from a single, public reservation called Yellowstone National Park to include 418 natural, historical, recreational, and cultural areas throughout the United States, its territories, and island possessions. ¹²

History of Pocahontas State Park, Virginia

On March 31, 1933, during the Great Depression, Franklin D. Roosevelt introduced one aspect of his “New Deal” which included The Civilian Conservation Corps (CCC). Hundreds of thousands of young men, between the ages of 18 and 25, left their homes for a distant job that paid all of $30 per month. Organized in military style companies of 200 men plus support staff, they had a dramatic impact on Virginia, in creating what is now Pocahontas State Park. One of the reasons for enlistment was noted by Christen Miller, Park Naturalist, - “They got three meals a day”, this was during a time when people were literally starving and standing in food lines.

Once they got to work, the men of the CCC did more than just reforest the land that was almost barren from lumbering that was done in the early 1900’s. They also constructed buildings, some of which are still in use today, built dams, which provide for scenic and recreational use, and made roads and trails in order to get to around the park. The park has approximately twelve square miles, originally purchased piece by piece in 1934, it was turned over to the State of Virginia in 1946. It is now operated by the Virginia Department of Conservation and Recreation. Wildlife that you can find in the park include beavers, otters, raccoons, fish, and deer just to name a few.¹³

Wildlife Corridors 

When natural habitats are no longer able to support the species present it results in the displacement or destruction of its biodiversity. Examples include harvesting fossil fuels, deforestation, dredging rivers, mowing fields, and very commonly urbanization. A solution to this problem has been the constructing of wildlife corridors. They serve a number of purposes including protecting wildlife and helping animal populations thrive. They function as means to increase biodiversity and decrease human-animal conflict such as animals being hit by motor vehicles and they help fix the negative effects of habitat fragmentation. Corridors allow both animals and humans to occupy virtually the same areas of land, and thus co-exist where without the corridor this would not be possible.

An example of a wildlife corridor is fencing installed along portions of the highway to funnel the wildlife into the safe corridors. There are special cameras that have caught a number of creatures using these passageways and bridges. There is photographic evidence of grizzly bears, deer, elk and cougars using the structures to bypass the road. Without corridors, animals can become isolated. They may not find food or even mates which reduces repopulation. Or in worst cases, the animals become extinct. Below in Figure 3¹⁴ is a really cool example of a wildlife corridor in Australia! Millions of red crabs march from their forest homes to the ocean to breed on Christmas Island. The corridor has specially designed "crab bridges" and tunnels to reduce crab casualties. It's the world's biggest annual land crab migration.

Figure 3 Christmas Island Bridge for crabs, Australia

There are three main factors in how corridors can stabilize a fragmented habitat¹⁵:

• Colonization—animals are able to move and occupy new areas when food sources or other natural resources are lacking in their core habitat.
• Migration—species that relocate seasonally can do so more safely and effectively when it does not interfere with human development barriers.
• Interbreeding—animals can find new mates in neighboring regions so that genetic diversity can increase and thus have a positive impact on the overall population.

Corridors can be made in two distinct areas—either water or land. Water corridors are called riparian ribbons and usually come in the form of rivers and streams. Land corridors come on a scale as large as wooded strips connecting larger woodland areas. However, they can also be as simple as a line of shrubs along a sidewalk.¹⁶