Content Background
Mass Extinctions
The Big Five
Extinction is a natural, biological phenomenon. It is so common that between 99% of all life that has ever existed on Earth has already gone extinct.4 5 The normal rate of extinction is known as background extinction. Typically, species last on our planet for only 1 to 10 million years.6 7 However, at certain points in our planet’s history, the rate of extinction has far exceeded the background extinction rate. Scientists refer to this phenomenon as a mass extinction.
Fossil records indicate there have been five major mass extinction events on Earth.8 9 10 11 The first, known as the Ordovician extinction, occurred about 440 million years ago (MA). It is thought that this was caused by global cooling and glaciation, causing sea levels to lower and mass amounts of marine invertebrates to go extinct. The second mass extinction occurred 365 MA and was known as the Late Devonian extinction. Similarly, it is believed global cooling led to the extinction of a vast marine communities. Other theories claim an extraterrestrial impact may have occurred, as well. The third mass extinction, the Permian extinction, which occurred about 252 MA, is believed to be the largest extinction wherein between 77% and 96% of life on Earth was wiped out. Like the others, the cause of the Permian extinction is debated. Some believe volcanic eruptions caused an increase in greenhouse gases and a toxic environment for life on Earth. Other theories link the extinction event to climate change or a potential asteroid impact. The fourth extinction, the Triassic extinction is also believed to be caused by global cooling, volcanic activity, or asteroid impact. Finally, the fifth mass extinction, the Late Cretaceous extinction, occurred 66 MA. It is the event well known for wiping out the dinosaurs. Like the other mass extinctions before it, the cause of this extinction has been debated for years, causes ranging from catastrophic asteroid impact to slow environmental changes.12 13 14 15
Our First Victims
It was long after the fifth mass extinction that early humans finally arrived on the scene. So, exactly how long was it before humans evolved into a species with ecosystems altering abilities? Many believe the first signs of human influence over the environment began around 100,000 to 200,000 years ago, when early humans began to migrate across the globe. By 13,000 years ago, humans had inhabited every continent except Antarctica.16 During this time, early humans adapted well to a variety of habitats, geography, and climates. While this was occurring, fossil records indicate that a rapid die off of megafauna species occurred. The alarming rate of this die off exceeds average background extinction rates. While there is evidence that points to climate change and global warming taking place at that time, many paleontologists are uncovering more evidence that suggests humans’ migratory patterns and hunting practices may have sparked the megafauna mass extinction event.17 18 19
One such example of evidence comes from the alignment of human arrival on each continent with the disappearance of that continent’s megafauna. The first “pulse” of extinctions occurred in Australia around 40,000 years ago, with North and South American extinctions following some 25,000 years ago. However, Madagascar’s megafauna survived until the Middle Ages and moas, a group of large flightless bird species, did not disappear in New Zealand until the Renaissance period. 20 As science writer Elizabeth Kolbert states in her book, The Sixth Extinction, “It’s hard to see how such a sequence could be squared with a single climate change event. The sequence of the pulses and the sequence of human settlement, meanwhile line up almost exactly.”21
Yet, many scientists do not believe this correlation is enough to point a finger solely at humans. Labs have begun studying fossilized herbivores droppings for traces of Sporomiella counts, a common fungus at the time. By doing so, researchers expected to see a decline in the vegetation population before the decline in megafauna herbivore population. If the change in climate was affecting the ecosystem as a whole, the loss of vegetation should have occurred first, consequently causing the mass die off of large herbivores after. However, that was not the case, suggesting something else was killing off these large creatures before the climate did. 22 Again, many scientists are not completely convinced in this correlation as well. These doubts are warranted, as each continent possessed different ecosystems and vastly different rates of extinction. 23 Regardless, the studies show that early humans had the capability of contributing to the mass extinction of megafauna. As biologist Telmo Pievani states, “Every time that Homo sapiens came somewhere, for someone else the death bell rang”24
The Sixth Extinction – The Human Role
We are currently living in a time known as the Anthropocene. The Oxford English dictionary defines this as “the current geological age, viewed as the period during which human activity has been the dominant influence on climate and the environment.” A drastic increase in the rate of changes to Earth’s natural systems began to occur after the Industrial Revolution, sparking an accelerated rate in which humans impact the Earth.25 At our current rates, it is speculated that humans are causing an average of one species to go extinct every 20 minutes.26 Some of these species are being killed off before we have a chance to discover or classify them.
According to evolutionary scientists Norman Myers and Niles Eldredge, this rate of mass extinction cannot be categorized as “catastrophism” or changes in the earth's crust from sudden violent and unusual events.27 Instead, they describe these rates of extinction as very realistic consequences of human actions. They continue to describe that it is never one single cause that threatens an ecosystem or biodiversity. Instead, threats to species and mass extinction rates are caused by a combination of factors.28
With such a high rate of extinction taking place, it is not hard to find examples of species already lost to the Earth. For example, the passenger pigeon no longer can be seen flying over America’s forests and fields in its massive flocks (see Figure 1).29 As the human population of the United States doubled between 1870 and 1900, so did the deforestation of much of the Northeastern and Midwestern forests. Our need for timber as fuel and the construction of homes, businesses, and infrastructure caused an extraordinary amount of passenger pigeon habitat loss. With these deforestation practices, passenger pigeons also lost their source of food. Although a law was passed to protect the birds in the 1880s, it did not restrict netting and was rarely enforced. Hunting and netting practices began to deplete what little population of passenger pigeons was left.30 By the early 1900s passenger pigeons had gone from “being one of the most abundant birds ever to extinction in less than a century.”31
Figure 1. Massive passenger pigeon flocks seen flying over field.
There are more examples of extinction caused by humans’ tendency to over hunt and fish, destroy habitats, and selfishly harvest natural resources. The great auk, Caribbean monk seal, Carolina parakeet, and Tasmanian tiger (thylacine) all fell victim to extinction in a fashion similar to the passenger pigeon. Today, amphibians are considered the class of animal most at risk of extinction. According to background extinction rates, typically, one amphibian goes extinct every thousand years. The current extinction rate of amphibians is forty-five thousand times higher than the background rate, leaving most herpetologists to witness multiple extinctions within their career.32
The extinction of one such amphibian, the golden toad, I found particularly interesting due to the circumstances of its demise. “More than 1,500 toads were observed in 1987, but only a single toad was observed at the main known breeding site in 1988 and 1989, while seven adult males and two adult females were recorded 4-5 km away in 1988.”33 The biologists who struggled to track the disappearance of the toad throughout the hills of El Valle, Panama were not racing against the bulldozers of deforestation. Instead, these students, biologists, and toads were fighting against a unique species of chytrid fungus known as Batrachochytrium dendrobatidis, or Bd.34
The earliest cases of chytrid fungus exist in South Africa. The second case of chytrid, outside of South Africa, was discovered on a green frog species in Québec, Canada.35 Since then, chytrid fungus has been found in vast regions of the Americas, Europe, and Australia, far from its continent of origin, Africa.36 37 Amphibians from different regions are reacting differently to the fungus, and in the case of the golden toad, some are completely wiped out. What is so remarkable about the particular case of the golden toad’s extinction is that on paper the finger can be pointed at the Bd fungus and the fungus alone. However, on closer examination studies have shown that “no geographic spreading pattern could be observed over time,” meaning that chytrid could not have jumped over oceans from continent to continent on its own.38 Rather, the spread of chytrid is linked to international trade, being passed along between continents by boat or plane39 40 This information asks us to once again look inward at ourselves as the reason the golden toad was victim to Bd in the first place.
Current Threats to Biodiversity
In this section, I explain the human imposed threats to Earth’s biodiversity by ecosystem. The specific threats to one ecosystem can be different from its neighbors’ threats. However, through years of research, scientists have developed a list of negative human’s impacts. Edward O. Wilson, a leading evolutionary biologist, proposed the HIPPO model to categorize our current threats to biodiversity:
“H Habitat fragmentation (forest clearance and conversion into pastures and intensive cultivations);
I Invasive species (able by themselves to cause local mass extinctions in entire regions as well as on islands and archipelagos);
P Population growth and urban macro-agglomerates;
P Pollution (agricultural, industrial, chemical pollution of air, water and soils);
O Overexploitation of biological resources by overfishing and overhunting”41
Although this list covers the majority of human imposed threats, it does not include the threat of climate change. Climate change is a unique threat to not just biodiversity and the environment, but also to humans, as well. The rate at which climate change is causing global temperatures to rise and environments to shift will likely take centuries to return to normal. We are seeing mass amounts of deglaciations, wildfires, coral bleaching, and loss of ecosystems. “On all inhabited continents in the past year, we have witnessed the economic and physical displacements of human populations due to flooding and drought, which in turn has overwhelmed natural systems.”42 Therefore, I am including climate change alongside the HIPPO model’s threats to biodiversity.
Marine Ecosystems
I would like to preface by stating that there is not one singular marine ecosystem. Below I describe the overarching threats to three major ecosystems that exist within our oceans: coastal ecosystems, coral reefs, and arctic ecosystems.
One of the threats to our ocean ecosystems is a result of over exploitation of its resources. As human populations increase, cultures and societies that depend on seafood as their main source of protein cause a demand for more fishing.43 As the world’s economy becomes more global, the demand for seafood can reach a much larger market. These unrestrained fishing practices also have been known to shift food webs. A notable example is the exploitive whaling industry.44 Industrial fishing practices also affect nontargeted species in marine ecosystems. Nontargeted marine species are considered fish, invertebrates, birds, or mammals that are accidentally caught while fishing for a specific species. Most of the time, nontargeted species are discarded, injured while being caught, or killed once caught. This is primarily caused from unsustainable fishing practices like bottom trawling and dynamite fishing.45 46
Another threat that can take many disruptive forms, is pollution. One such type of pollution that primarily affects coastal regions and coral reefs is eutrophication. Eutrophication is the introduction of excess nutrient (often nitrogen) enrichment, ultimately leading to a cycle of enhanced algae blooms.47 48 Eventually, the enriched algae bloom dies and decomposes leading to a depletion of oxygen in the water, resulting in a “dead zone” that can suffocate marine species living within the area. Ocean water, or fresh water, can become polluted with excess nitrogen through fertilizer and fossil fuel combustion runoff. Annually, the Gulf of Mexico develops a dead zone from the mass amount of polluted runoff originating in America’s farm belt and traveling down the Mississippi River.49
Other pollutants found in marine ecosystems include organic pollutants, such as brominated flame-retardant and pesticides entering our oceans through river disposal. There are large amounts of heavy metals from offshore dumping, pharmaceutical waste, and sewage runoff. These metals include mercury, cadmium, silver, nickel, selenium, lead, copper, chromium, arsenic, and zinc. Oil spills have caused long-term effects on ecosystems. It is estimated 10 million tons of oil has entered marine ecosystems by means of spills, ballast water, maintenance of refineries, and land-based dumping. Studies have shown these pollutants and toxins can be traced to all parts of the ocean, and cause abnormalities, reproductive failures, disease, and immune suppression in marine species.50
The final major pollutant threatening ocean ecosystems is plastics. Plastics that have entered marine ecosystems can cause mortality in wildlife by entanglement, ghost fishing, and ingestion.51 Plastic debris can range in large clumps of knotted waste to bits of plastic eroded down to microscopic particles. This range in size means plastics threaten a vast majority of marine species. Another harmful characteristic of plastics is their ability to float wherever the ocean currents take them. Whirlpools and circular motions within ocean currents have caused large collections of plastic debris to accumulate together, one such mass exists in the North Pacific central gyre.52
The next major threat to marine ecosystems is habitat fragmentation. On the surface, the ocean might look like vast amounts of water interconnected between continents. Space to live seems abundant from our view from the surface. However, not every marine species has the capability or instinct to simply swim to any part of the ocean. Destruction of ocean habitats comes at a high cost to biodiversity. Coastal ecosystems and coral reefs are particularly affected. Wetlands are drained and converted into hardened shorelines and oyster reefs have been overharvested past the point of replenishment. Developed countries have passed laws conserving and rebuilding reefs and coastal ecosystems. However, countries of the tropics are most at risk of losing their coastal marine ecosystems.53
Artic ecosystems have seen the loss of habitat not by direct humans’ influence, but by human induced climate change and global warming. Increases in the temperature of the atmosphere and Arctic Ocean water have directly caused a decrease in ice caps at a rate of 10% per decade. Some predict the Arctic Ocean will be ice-free by 2050. Polar bears, seals, and ice dwelling amphipods are directly feeling the effects of the melting ice.54
Another effect of human imposed climate change and global warming is the increase of carbon in the atmosphere being absorbed into our oceans. This has led to an acidification of ocean water. The pH levels of the ocean have dropped 0.1 pH since the Industrial Revolution, and it is believed the ocean will continue to drop another 0.3 to 0.4 pH units by the end of the century.55 Such small changes can be detrimental to reef-building coral which grows by adding mass through calcification. When carbon levels and ocean acidity increase, coral loses its ability to calcify. The more acidic the ocean becomes, the less reef-building coral will grow.56 57 Similar effects to acidification can be seen in other shelled organisms, leaving many ecosystems built around shelled invertebrates extremely vulnerable.58
Climate change and global warming cause another problem for coral reefs. Coral is a type of animal known as a polyp. Coral provide a home for a microscopic plant known as zooxanthellae. This plant is the sources of the coral’s vibrant colors. Much like the way humans and plants rely on each other through photosynthesis, coral releases carbon dioxide into the water, which is consumed by the zooxanthellae. In return, zooxanthellae produce carbohydrates and oxygen, which are harvested by the coral and used as energy to grow. However, as the ocean water warms with rising global temperatures, zooxanthellae produce too much oxygen and coral polyps expel them, leaving the coral bare and colorless. This process is also known as “coral bleaching.” The rate and intensity coral is bleaching has resulted in coral species being listed as threatened, exceeding all terrestrial animal groups endangered apart from amphibians.59 In addition, corals serve as a keystone species to reef and coastal ecosystems. Coral is a species that other organisms create habitats out of. An entire ecosystem can emerge from where coral grows. As Ken Calderia, an atmospheric scientist, states, “corals build the architecture of the ecosystem…So it’s pretty clear if they go, the whole ecosystem goes.”60
Tropical Rainforests
Tropical rainforests are the world’s most biologically diverse ecosystems. With that diversity, comes an equally diverse list of threats caused by humans. The main driver of biodiversity loss comes in the form of habitat fragmentation through deforestation. The 1980s and 1990s saw an increase in human population size, leading to hundreds of small-scale farms and rural communities living within tropical forests. This population of people became the primary drivers of deforestation. However, their capabilities of habitat fragmentation were limited to hand machetes, axes, and chainsaws. In more recent years, the globalization of the economy has led more industries to become involved in rainforest deforestation. The small-scale ranches and farmers from the 1980s and 1990s have been replaced with large scale agriculture, plantations, ranching, logging industry, fossil fuel and mineral extraction, and expanding infrastructure. Therefore, the rate at which tropical rainforests are shrinking has increased. More corporations mean more funding. More funding means more bulldozers can be purchased.61
As the global economy grows, human interest in the tropical rainforests has grown. Road expansion has made once remote regions of rainforests more accessible. This has opened the door for more illegal land colonization, logging, hunting, and mining. Powerful countries are putting more pressure on poorer tropical governments and communities to exploit their biological resources. For example, China has become the world’s largest importer of tropical timber. More than half of all timber being shipped around the world is heading to China.62 Another economy-driven threat to tropical rainforests comes from the desire to find alternative biofuel sources. Currently 85 million barrels of petroleum are consumed each year. Some believe Earth has reached its “peak oil,” meaning supply will begin to decline causing humans to turn to biofuel as an alternative. Tropical locations serve as the best climate and cheapest land for the growth of biofuel producing plants. Both the demand for timber from powerful outside nations and the potential necessity of biofuel will only increase the rate at which tropical rainforests habitats are altered or destroyed. Either scenario will leave the land inhabitable for many species of wildlife.63
Another major threat to tropical rainforests comes in the form of invasive species. As humans become more internationally mobile, pathogens are more easily transferred from continent to continent. Pathogens can include bacteria, viruses, or other microorganisms that cause diseases. While tropical ecosystems are on average already more diverse than other biomes, pathogen invaders have been particularly impactful to tropical rainforests. New pathogens introduced to tropical rainforests can create drastic mortality rates in plants and animals. As stated previously, the chytrid fungus alone has caused the extinction of 200 frog species.64 Other notable examples are the avian malaria parasites, which infected Hawaiian birds, and Ebola virus, which is transferring and causing mass die offs of human communities in Africa, but also large populations of gorillas and chimpanzees. The invasive and deadly nature of pathogens, specifically in tropical locations, shows that wildlife is not the only group threatened by our globalized world. Humans are putting other human health at risk as well.65
Finally, the last threat to tropical rainforests is climate change. Unlike other ecosystems of the world where temperatures can fluctuate with seasons, tropics tend to have a narrower range in average temperatures. This means the species that reside in tropical climates are less likely to adapt to shifting temperature changes. Although tropical rainforests are typically warmer, species living there will struggle to withstand the ever-warming temperatures, thus, increasing the likelihood for extinction. A study suggests that native mountain residing vertebrates from the tropics of Queensland, Australia will have to adjust to a 2°C increase in mean temperature. The study also suggests that this increase in average temperature could result in one eighth of species extinction. Although studies like this one exist, it is difficult to predict exactly how ecosystems will react to global climate change. Preventative measure for tropical regions’ communities and wildlife can be challenging to develop when the future of its ecosystems is difficult to predict.66
Grasslands
Earth’s grasslands and savannas cover 40% of Earth’s terrestrial surface. Historically, grasslands have been a birthplace for civilization. Nearly every cereal crop - barely, rice, rye, sorghum, and wheat - grew from grasslands. This ecosystem served as the pre-domesticated home of cattle, donkey, goats, and sheep. Today, grasslands still play a vital cultural role in agricultural and pastoral communities, but are facing a devastating threat of habitat fragmentation through land conversion.67 Open grassland ecosystems are being disproportionally disrupted by land conversion into agricultural plots to serve the increasing human population size across the globe. North American prairies have declined by 97% since 1830, Sub-Saharan African grasslands have lost 35 million km2, South American has lost 1.4 million km2, and Asia has lost 1.2 million km2.68
With the conversion of natural grasslands into agricultural plots comes the disruption of wildlife migratory and grazing patterns. Many governments, organizations, and communities are aware of these implications towards wildlife. However, bird flight patterns and large mammal migration does not conform to local, state, or international borders, making conservation policies lack continuity.69 Additionally, the sizes of established conservancies are usually too small and resemble islands, surrounded by human influences and infrastructure. When this occurs, a species’ population size decreases, leading to less selective breeding. Negative effects can be seen in species genetic diversity through inbreeding and abnormalities. For example, a population of wolves colonized Isle Royale off the coast of Lake Superior in the 1940s. Throughout the decades, a winter ice bridge formed less and less frequently, limiting the trips these wolves could take to breed with other wolf populations, reducing their genetic diversity and causing inbreeding-related problems. Since the decline in these opportunities, the Isle Royale wolf population has greatly declined. In 2015, only three wolves remained, one of which could be observed with a visibly shorter tail and twisted spine.70 Although these wolves do not reside in a grassland community, the competition over land use creates challenges connecting ecosystems throughout the world’s grasslands.
A large motivator to convert grassland into farmland comes from the demand for biofuel. The vast openness of grasslands provides enough space for an increase in agricultural productivity needed to meet the demand for biofuel. Unfortunately, modern agricultural practices negatively affect water and air quality by utilizing fertilizer and pesticides and depleting the soil of its nutrients. Such practices create soil more susceptible to erosion, resulting in the fertilizer and pesticide pollutant runoff, subsequently creating algae blooms and “dead zones” in freshwater and ocean habitats. In addition, the plants being grown for biofuel cannot store as much carbon as the natural flora grown in grasslands.71 Grasslands can store more carbon in the soil than above ground vegetation.72 In other words, grasslands are ecosystem that suffer disproportionately shrinking. Yet, on a planet with more and more carbon in our atmosphere, grasslands could help store the gas causing large global climate change.
Deserts
Deserts have long been the forgotten ecosystem in the public discussions of conservation. The notion that deserts are barren biomes that lack biodiversity is simply not true. In fact, this perception of desert ecosystems has led to the decrease in desert biodiversity that is disproportionately unchecked compared to other ecosystems.73 74 However, like the ecosystems described above, deserts have not remained untouched by the age of the Anthropocene.
The Sahara Desert is “the largest warm desert in the world with land coverage, including the Sahel, of about 1,123,000 km2.”75 One of the biggest threats to its ecosystems includes habitat fragmentation. For deserts, fragmentation can be shaped by multiple human sources. One source comes in the form of competition over limited resources. Humans have lived in deserts for thousands of years. However, climate change is affecting deserts by limiting the little supply of resources that already was. Humans are now in competition with wildlife over these resources. Agricultural expansion and over grazing vegetated regions of deserts have displaced wildlife from their natural habitats. Water sources are being completely extracted or diverted towards dense human populations or industry. What water and land are left to wildlife are being polluted.76 77 In the United States, the Mojave Desert has seen habitat fragmentation due to military training sites, highway construction and vehicle use, and livestock grazing.78
Another source of habitat fragmentation comes from the investment in drilling and mining. The physical border of the oil industry is cutting off wildlife corridors and connectivity between protected areas.79 Niger, which has historically housed local desert species, has recently increased their oil extraction. “Such increased oil prospection activities have, for example, now led to the endangerment of the last known population of addax.”80 In the United States southwest, the Trump administration is proposing to eliminate 85% of Bear Ears National Monument and half the size of Grand Staircase-Escalante National Monument. This proposal has been made in order to access major coal deposits that currently sit within Grand Staircase-Escalante and uranium with Bear Ears. These protected areas have previously helped scientists study how rangeland practices can affect ecologically diverse ecosystems, and are currently home to populations of mule deer, black bears, and mountain lions.81
With the increased human encroachment of desert ecosystems, comes the threat of invasive species. In desert ecosystems, invasive species can present two problems. First, some invasive species have the ability to overtake and outnumber native species. This can alter the food availability for some wildlife.82 In desert ecosystems, resources are scarce, and wildlife has adapted to survive off a limited menu. In the Mojave Desert, desert tortoises are struggling to consume enough nutrient efficient vegetation due to the abundance of nonnative plants. The second concern that can arise with invasive species in deserts is their ability to withstand environmental conditions. Deserts are hot and the vegetation there is designed to endure the hot and dry climate. Nonnative vegetation does not have the same capabilities and can be more susceptible to wildfires. Again, in the Mojave Desert, wildfires have been spurred on by the invasive grass Bromus rubens.83
Mountains
Mountains are a geographic feature revered for their natural beauty, cultural symbolism, and spiritual significance. Often mountains are placed under protection for these reasons. In 2009, about 17% of the world’s mountain areas, outside of Antarctica, were under protection of some kind, while only about 13% of Earth’s terrestrial land, outside of Antarctica, is protected.84 However, mountain ecosystems remoteness and low population density does not make them immune to the threats of the Anthropocene. Mountain ranges exist in our deserts, tropical rainforests, and temperate climates. The location of the mountain range and climate it resides in can determine the type of threats a mountain ecosystem may face.
Many mountain ecosystems are threatened by habitat fragmentation. Their ecosystems are shrinking and losing connectivity through human imposed methods previously stated, such as deforestation and growth of agricultural industry. However, some mountain ecosystems face unique forms of habitat fragmentation. European mountains, while relatively well protected, are experiencing the loss of habitat due to the increase in human recreational infrastructure, such as ski resort construction.85
Another method of habitat fragmentation is in the form of mining and mountaintop-removal. A concentration of areas along the Appalachian Mountains have faced the environmental impact of mountaintop-removal mining for coal since the 1960s when the practice began. The removal of a mountaintop does not just significantly decrease the size of the mountain ecosystem, it creates a landslide-like effect of environmental concerns that spread down into lower elevated regions of the mountain community. Soil composition changes, and freshwater streams become susceptible to more sediment and mining site pollutant runoff. This in turn affects the biodiversity of freshwater streams and the drinking supply for the surrounding ecosystems and humans. Studies have shown that there is a link between the practice of mountaintop-removal mining and the loss of benthic macroinvertebrates, as well as the decline of salamander populations in below valley streams.86
This region of North America is not the only mountain ecosystem affected by mining caused habitat fragmentation. Africa is currently facing a mining boom, where three regions with unique biodiversity are at risk. One of these regions is the Albertine Rift Mountains. Outside countries, such as China, Brazil, Russia, India, Canada, and Australia are increasing investments in African mines. With this growth in human interest comes direct human impact. For example, interest in the iron-ore within the Mount Nimba Biosphere Reserve, a World Heritage Site, has led to a decrease in the site’s size by 1,550 hectares, or about 3,830 acres. Further fragmentation is being caused by the construction of railroads to link mining sites to coastlines.87
Invasive species are another threat to most mountain ecosystems. Both direct and indirect human introduction of nonnative species in mountain regions has occurred. Humans are increasingly using mountain regions for both recreational and conservation-minded ecotourism purposes. In Europe, an increase of nonnative species has been intentionally introduced to communities around ski slopes and mountain resorts.88 The North American little brown bat population is rapidly decreasing from the caves of the eastern United States, leaving the species endangered. An introduction of a white power-like fungus has been killing off little brown bats since 2006. Initially, scientists were puzzled as to why the white fungus was suddenly affecting the bat population, suspecting it to be an introduced, nonnative species. These suspicions were slightly confirmed, when photos of the first documented case of bats showing the effects of the fungi, named white-nose syndrome, were observed in the Howe Caverns of upstate New York.89 Wildlife biologist Al Hicks remarks, “It’s kind of interesting that the first record we have of this is a photograph from a commercial cave in New York that gets about two hundred thousand visits a year.”90
The second means of nonnative species being introduced to mountain regions is through human caused climate change. Warming climates are causing lower level plant species to populate higher elevated mountain regions. It is important to note that many of these plant species are native to the region, but do not historically grow at higher elevations. Some mountain ecosystem climates seem to be more affected by this form of invasion than others. For example, a change in flora can be seen at Haleakala National Park on the Hawaiian island of Maui. Pines have been invading high elevations, completely transforming the communities that were typically shrublands into tall forests. Similar transformation of vegetation composition can be seen in Chile and South Africa.91
Climate change is also directly affecting the ice caps, snow, and glaciers on top of many mountains around the world. Currently, mountain cryosphere (snow, ice, or permafrost) serves as an extremely vital source of water. 50% of the world’s population depends on fresh water from mountain regions. However, over recent decades, rising air temperatures have caused a reduction in the area and volume of glaciers, snow, and ice.92 While it is typically a less diverse area of wildlife, the snow-covered ecosystems of mountain tops play an important role in the health of ecosystems below it. Rain that falls on top of snow causes a variety of threats and impact on wildlife communities and human society. Increased erosion and movement of sediment can cause flooding, landslides, and glacier lake outbursts. The deposition of sediment will affect water quality for humans and lower level aquatic habitats.93 Mountain ecosystems are increasingly becoming a great indicator of how the impact of one ecosystem can trickle down and affect many others.
Community of Caretakers
At this point, I have described in detail how humans are negatively impacting and exploiting Earth’s resources and ecosystems. With all this information, one may ask, why does the preservation of biodiversity matter? The majority of humans on Earth have gone on living their lives since the disappearance of the passenger pigeon and golden toad. So why should one care about the fate of the little brown bat, desert addax, or coral reefs? In the words of Dr. Martin Luther King Jr.,
“It really boils down to this: that all life is interrelated. We are all caught in an inescapable network of mutuality, tied into a single garment of destiny. Whatever affects one destiny, affects all indirectly.”94
Beyond humanity’s capacity to empathize with others, there is scientific evidence that a community of caretakers can benefit the world as a whole. In 2019, the United Nations (UN) released a report on the accelerating rate of species extinction, describing its implications on human well-being. Around 4 billion people rely on natural medicine or medicines derived by nature.95 $577 billion US dollars of global crops are at risk from the loss of pollinators.96 97 Protecting pollinating species will benefit natural ecosystems and the world’s agricultural economy. Over exploitation of resources and rapid habitat destruction have led to poor soil quality and desertification of ecosystems, shrinking the land available for humans to produce food. On the other hand, well preserved natural vegetation and wetlands have proved to help regulate water flow, soil erosion, and reduce flash flooding. The preservation of these ecosystems can protect communities from natural disasters, while protecting water supply.98 Already, 40% of the global population lacks access to clean and safe drinking water.99 The melting snow and ice caps on mountains will cause more frequent sediment erosion, adding another threat to Earth’s water supply, but also may cause infilling of hydropower reservoirs, turbine abrasion, and destruction to human developed infrastructure.100
Thankfully, not every human or community’s goal is to exploit Earth’s natural resources at the expense of wildlife and biodiversity. There are many communities that have preserved indigenous cultures’ traditions, and they practice these methods of coexisting alongside nature. Studies have shown that extinction rates are slower on land managed by indigenous groups.101 For example, indigenous communities of the Pacific Northwest have been involved in restoring shellfish populations and native plant species to the region. Other agricultural practices that integrate cultivated and native plants into a garden have yielded cases of 300-500 species within a garden.102
It is becoming clear that there needs to be more recognition and partnerships between industry, the scientific community, and indigenous communities. In Hungary, traditional grazing practices have long been allowed throughout the country’s grasslands. Yet, upon the establishment of national parks, government authorities restricted and outright banned these practices on the grasslands.103 However, other outside communities are embracing the lessons that can be learned from indigenous communities, such as the successful partnership between American pastoralists, ranchers, scientists, and the Maasai people of Kenya. The American ranchers gave insight to the Maasai about their experiences of land subdivisions, degradation, and loss of livelihood. They educated the Maasai on adapting practices to a changing economy. The Maasai educated the ranchers about communal herding and avoidance of localized drought. The exchange of experiences, knowledge, and practices between the two communities was summarized by a Maasai elder “Your past is our future and our past is your future.”104
Other communities are using conservation as a means of regaining power and control over their land, which has helped people rise out of poverty. Namibia has seen one of the most successful community-based conservation models that has expanded globally, known as community based natural resource management program (CBNRM) and Integrated Rural Development and Nature Conservation (IRDNC).105 106 107 Colonization and Apartheid left the black population of Namibia without the education and resources to defend their livestock from wildlife predators. Drought and poverty led black citizens to turn to illegal poaching as a method of income since legal game hunting was limited to white citizens.108 109 In the 1960s the IRDNC began developing a community-based conservation movement that helped black communities regain control over their own land and livestock, and offered opportunities for decision-making on conservation topics.110 111 112 The IRDNC needed members of the community who were knowledgeable about the surrounding environment and wildlife to work within their program. Local Namibian community leaders realized the best people for this job were the poachers. The IRDNC took into account the history of these Namibian communities, put the needs of the community first, and provided job opportunities for poachers.113
The benefits of such a method of conservation can be seen through the access of property rights and power given back to the communities of Namibia. Individuals within the community now have medical access, scholarship opportunities, support for local teachers, human/wildlife insurance for pastoralists, support for traditional authorities, and community sport teams. 114 Namibia has seen an increase in populations of elephants, springbok, oryx, zebra, lions, leopards, and the largest population of free roaming black rhino in the world.115 116 The entire country has seen a near disappearance of poaching and illegal hunting.117
Jane Goodall has seen a similar success using a community-based conservation model in the communities surrounding Gombe National Park and Lake Tanganyika called TACARE. Like the CBNRM and IRDNC in Namibia, TACARE focuses on improving the livelihood of people in the villages over strict conservation practices. Goodall explained that the program helps villagers obtain freshwater wells, construct suitable schools, provide microloans to women, provide scholarships for girls to finish secondary school, and improve family planning education and education about HIV/AIDS.118 She states in her TED talk that “as a result of this program, something’s happening for conservation.”119 By improving the quality of the people around the Great Gombe Ecosystem, villagers have a better understanding of their connection to the ecosystem, and practice better conservation practices.120
The 2019 UN report provides disheartening information such as the fact that since 1992 urban areas more than doubled, plastic pollution has increased tenfold since 1980, about 300-400 million tons of heavy metals, solvents, toxic sludge, and other wastes are entering coastal ecosystems annually, and there are more than 400 ocean “dead zones” that are collectively greater than the size of the United Kingdom. The report totals that “Three-quarters of the land-based environment and about 66% of the marine environment have been significantly altered by human actions.”121 However, it also states that “On average these trends have been less severe or avoided in areas held or managed by Indigenous Peoples and Local Communities.”122 The examples of indigenous practices and community-based conservation above provide the entire world with exemplary models of how humanity can break away from our exploitive practices.
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