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22.4: Preserving Biodiversity

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    Preserving Biodiversity

    • Please read and watch the following Learning Resources
    • Reading the material for understanding, and taking notes during videos, will take approximately 2 hours.
    • Optional Activities are embedded.
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    Preserving biodiversity is an extraordinary challenge that must be met by a greater understanding of biodiversity itself, changes in human behavior and beliefs, and various preservation strategies. The threats to biodiversity have been recognized for some time. Today, the main efforts to preserve biodiversity involve legislative approaches to regulate human and corporate behavior, setting aside protected areas, and habitat restoration. A lofty goal is to protect 50% of the Earth's natural spaces for wildlife known as the Half-Earth Project, as described by the late Dr. E.O. Wilson below. Others, such as David Attenborough and Dr. Sylvia Earle, weigh in on the issue as well. 



    6-minute video with famed conservationist David Attenborough

    6-minute video with famed biologist E.O. Wilson

    3-minute video with famed marine biologist Sylvia Earle
    Question after watching: What common themes do you find in the messages of these conservation ambassadors?

    Changing Human Behavior

    Ultimately, human behavior will change when human values change. At present, the growing urbanization of the human population is a force that poses challenges to the valuing of biodiversity. Legal avenues can help to protect biodiversity in the meantime.

    International Legislation

    Legislation throughout the world has been enacted to protect species. The legislation includes international treaties as well as national and provincial laws. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) agreement came into force in 1975. The agreement, and the national legislation that supports it in Canada and most other countries, provides a legal framework for preventing approximately 33,000 listed species from being transported across national borders, thus protecting them from being caught or killed when international trade is involved. The treaty is limited in its reach because it only deals with the international movement of organisms or their parts. It is also limited by some countries’ ability or willingness to enforce the treaty and supporting legislation. The illegal trade in organisms and their parts is probably a market in the hundreds of millions of dollars. Illegal wildlife trade is monitored by a non-profit: Trade Records Analysis of Flora and Fauna in Commerce (TRAFFIC).

    The Convention on Biological Diversity is now the leading international treaty to advance the conservation of biodiversity, within the context of a comprehensive agenda for sustainable development. The three key goals of the Convention are the conservation of biodiversity, the sustainable use of its components, and the equitable sharing of benefits from the use of genetic resources. The 194 ratified parties to the Convention are engaged in a multitude of cooperative initiatives and information and technology sharing, and are committed to identify and conserve their biodiversity.

    A key action is to periodically undertake science assessments of the status of global biodiversity. Broadly speaking, the most recent assessment found that the prospects of biodiversity were rapidly worsening in many parts of the world, although considerable progress was being made in cooperative planning and in the designation of protected areas and other conservation measures in many countries. It is too soon to tell whether these international actions will be successful because the programs began only in the late 1970s (as an earlier program called the World Conservation Strategy). However, it is encouraging to know that this sort of comprehensive international effort exists and that almost all of Earth’s nations are participating, including countries in all stages of economic development.

    On an international level, important wilderness lands have been designated by the United Nations through its "Man and the Biosphere Program." This program was established in 1973 to protect examples of major natural regions throughout the world, and provide opportunities for ecological research and education.

    Biosphere reserves are organized into three interrelated zones: the core area, the buffer zone and the transition area. The core area contains the landscape and ecosystems to be preserved. The buffer zone is an area where activities are controlled to protect the core area. The outer transition area contains a variety of agricultural activities, human settlements and other uses. Local communities, conservation agencies, scientists and private enterprises that have a stake in the management of the region work together to make the reserves work. Mt Kenya in Africa and the Galapagos Islands are examples of wilderness areas protected under this provision.

    Optional Activity \(\PageIndex{1}\)

    The Convention on International Trade in Endangered Species (CITES) passed a resolution to protect rhinoceroses in the wild. Rhinoceroses have been hunted to the brink of extinction because their horns, which are made of the protein keratin, the same as humans' fingernails and hair, are considered an aphrodisiac and a powerful drug in some cultures. Why does the protection of rhinoceroses require an international agreement?

    1. The rhinoceroses are hunted in their native countries, but the trade crosses borders.
    2. The use of rhinoceros’ horns as an aphrodisiac has showed negative effects internationally.
    3. The hunters from different countries travel to the native country to hunt for rhinoceroses.
    4. Their demand is greater in foreign countries as compared to their native countries.

    A. The rhinoceroses are hunted in their native countries, but the trade crosses borders.

    US Legislation

    Within many countries there are laws that protect endangered species and that regulate hunting and fishing. In the United States, the Endangered Species Act (ESA) was enacted in 1973. When an at-risk species is listed by the Act, the U.S. Fish & Wildlife Service is required by law to develop a management plan to protect the species and bring it back to sustainable numbers. The ESA, and others like it in other countries, is a useful tool, but it suffers because it is often difficult to get a species listed or to get an effective management plan in place once a species is listed.

    The Migratory Bird Treaty Act (MBTA) is an agreement between the United States and Canada that was signed into law in 1918 in response to declines in North American bird species caused by hunting. The Act now lists over 800 protected species. It makes it illegal to disturb or kill the protected species or distribute their parts (much of the hunting of birds in the past was for their feathers). Examples of protected species include northern cardinals, the red-tailed hawk, and the American black vulture.

    The ESA recognizes five categories of risk, each of which has a specific meaning in terms of imminent threats to the future survival of the species (COSEWIC, 2015).

    • Extinct refers to any species of wildlife that was formerly indigenous to the US but no longer exists anywhere in the world. 
    • Extirpated refers to any species or subspecies that was formerly indigenous to the US but now only survives in the captivity or elsewhere, usually in Canada or Mexico.
    • Endangered refers to native species that are faced with imminent extinction or extirpation throughout all or a significant portion of their range. 
    • Threatened refers to any indigenous taxon that is likely to become critically imperiled unless factors affecting its status are reversed. 
    • Vulnerable refers to any indigenous species that is not currently imperiled but is at risk of becoming so because of small or declining numbers, occurrence at the fringe of its range or in restricted areas, habitat fragmentation, or some other reason. 

    It must be recognized that the designation of species at risk is a continuing and always incomplete process. For instance, because the conservation status of only a few species of invertebrates has been investigated, critically imperiled species in this group are enormously under-represented in the ESA list. Unfortunately, more rapid progress is constrained by a shortage of funding for research and monitoring of endangered species, and by a lack of specialists with the necessary taxonomic and ecological skills and knowledge.

    Of course, it is not sufficient merely to designate species as being at risk of extirpation or extinction. If their status is to be improved, the species and their habitats must also be protected. Remarkably, the US federal government has not yet enacted effective legislation to protect endangered species and their habitat across the whole of the country. However, this situation is starting to change. 

    However, federal legislation has little direct influence on the status of the many threatened and vulnerable that are living on state, private, or Indigenous land. Most importantly, the Act does not fully address the protection of habitat of critically imperiled species off federal land. To some degree, this deficiency is covered by legislation that has been enacted by states. However, their legislations are also not very effective, because they, too, do not protect the habitat of species at risk, especially on private land. Such a piecemeal approach results in uneven levels of protection for species-at-risk, which is unacceptable from the conservation viewpoint.

    The lack of effective protection of species-at-risk in US is raising controversy. Governments feel the need to demonstrate that they are making rapid progress toward sustainability, an important component of which involves the protection of native species and their habitats. Unfortunately, the progress to date has been lacking and is not yet effective in protecting our biodiversity most at-risk. Hopefully, the lobbying efforts of non-governmental organizations (NGOs) will result in appropriate changes to the currently weak legislation of all levels of government. 

    Most of the natural ecosystems of the United States now exist only as small remnants of their former extent. Because of this, they are as endangered as the species they support. The most endangered of our natural ecosystems are:

    • the tall-grass prairie of the Midwest
    • old-growth forests of all of the US 
    • dry coastal forests of the southeast 
    • deserts of the southwest
    • most freshwater wetlands

    Some of these ecosystems are also rich in endangered species. It is imperative that the remaining areas of these endangered ecosystems become preserved in parks and other kinds of protected areas.


    In this 3 min video, you will be introduced to the argument that biodiversity loss results in economic loss in diverse ways, therefore natural resource management practices need to be applied.
    Question after watching: Do you agree that biodiversity loss should be treated with natural resource management practices? What are the advantages and disadvantages of doing this?

    Indigenous Connections: Preserving Salmon Fisheries

    "Pacific salmon—fish known by a host of Indigenous names throughout their vast geographic range (genus Oncorhynchus)—have been in a state of decline in British Columbia (BC), Canada for several decades (Price et al. 2017) such that a growing number of wild salmon populations have been assessed as “at risk”’ (from Special Concern (n = 5 populations) to Threatened (n = 3) to Endangered (n = 10)) by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC; Government of Canada 2018). As both ecological and cultural keystone species, without the continued existence of salmon, ecosystems and societies alike would be entirely transformed (Willson and Halupka 1995; Garibaldi and Turner 2004)."1

    "For the Nisga’a, which sits on the BC–Alaska border (and to which the lead author belongs), salmon are vital. They shape ayuukhl (code of law) and adaawak (oral histories), they figure centrally in yukw (feasts, known externally as “potlatches”), and they are a focal point of the Nisga’a Treaty (2000) that defines Nisga’a rights tied specifically to salmon. As Nisga’a and indeed many Indigenous nations identify as “Salmon People” (Columbia River Inter-Tribal Fish Commission 2020; Earth Economics 2021), there is serious concern about what will become of salmon-linked cultures, economies, knowledges, languages, laws, well-being, and worldviews as the annual return of these anadromous fish to rivers across the Pacific Northwest become increasingly unpredictable and, in many systems, Indigenous fisheries for wild salmon become a shadow of their former selves (Jacob, McDaniels and Hinch 2010; Atlas et al. 2021). Decolonial research strategies that respect Indigenous intellectual traditions and affirm Indigenous control over Indigenous knowledge are critical to the maintenance and recovery of salmon-based knowledge systems and salmon populations (Simpson 2004; Bingham et al. 2021)."1

    Not only would it behoove fisheries scientists to use all and the best tools and knowledge available at this time of [social-ecological] crisis, irrespective of their origin and the perceived objectivity and superiority of Western scientific approaches, but this would importantly serve decolonial and reconciliatory efforts that help rectify uneven power relations, knowledge inequalities, and other racially linked and unjust dynamics in fisheries.3 

    "Indigenous peoples have been managing landscapes more or less sustainably for thousands of years. Indigenous peoples’ successes stem, in part, from the fact that many Indigenous worldviews recognize that species do not exist in isolation; they are part of a natural system."2

    "TEK provides invaluable time-tested resource management practices that can be used alongside WS to develop more workable and effective approaches to current resource management strategies than either could accomplish alone. In fact, it has become a policy requirement in Canada, and in particular Northern Canada, that TEK be incorporated into environmental assessments affecting wildlife management including: migratory birds, species at risk, forest practices, and fisheries management (Usher, 2000)."3

    The Nisga'a Nation's understanding of, and work with, Pacific salmon is an excellent example of the role that Indigenous Science plays in understanding biodiversity and how to protect species and habitat in a sustainable manner.

    "Through partnerships with 18 communities of “Salmon People” and semi-structured interviews with 48 knowledge holders (i.e., Elders), we learned that, on average, Elders spent more than half of a century actively engaged in salmon fishing and processing. Modern salmon catches are reported to be approximately one-sixth of what they were estimated to be five to seven decades ago, and the top five threats to salmon identified by Elders included (i) aquaculture, (ii) climate change, (iii) contaminants, (iv) industrial development, and (v) infectious diseases. Threat priorities varied regionally, reflecting distinct lived experiences and regional variation in the prevalence and impact of different threats. Elders perceived threats to salmon equally as threats to aquatic health and human well-being, with evidence that the relationships between people and water, and salmon and people, are being profoundly transformed."1

    "The Nisga’a people of northern British Columbia live in the Nass Valley near Alaska. Every spring, members of some Nisga’a families still walk their salmon streams to ensure that spawning channels are clear of debris and that salmon are not obstructed in their ascent to spawning grounds. Concerned with the multiple perils faced by their Nass River salmon, the Nisga’a have themselves implemented a salmon protection project that uses both the ancient technology and wisdom practices, as well as modern statistical methods of data analysis to provide more reliable fish counts than electronic tracking systems (Figure \(\PageIndex{1}\)). The Nisga’a project, which earned a Department of Fisheries and Oceans Canada award, is described in the following account by Corsiglia and Snively (1997)

    "Observing that electronic fish counters can be inaccurate, the Nisga’a have instituted an ingenious fish counting system in the Nass River that combines ancient fish wheel technology with modern statistical methods. The ancient fish wheel was made of cedar wood and nettle fibre mesh, and the elongated axle of the fish wheel was fitted with three parallel vanes constructed in the form of large, flattened dip nets. The swift moving downstream current turned the wheel by exerting force against the submerged vanes, and as the companion vanes rose in turn, they gently caught and uplifted the fish as they swam upriver. As each vane rose from the horizontal, the fish slid toward wooden baffles that guided them out of the side of the fish wheel and into submerged holding baskets. This technology provided the Nisga’a with an effortless fishing technique as well as a ready supply of fresh salmon."3 (p. 19)

    Nisga'a fish wheel showing holding pen
    Figure \(\PageIndex{1}\). Nisga’a fish wheel showing holding pen. Illustration by Laura Corsiglia (1997).

    "Modern Nisga’a fishing wheels are made of aircraft aluminum and nylon mesh. Like their predecessors, these fish wheels allow fish to be captured live and held in holding tanks. This enables the Nisga’a to tag and count the fish by means of statistical analysis. Returning salmon are first caught using a fish wheel at a lower river station where fish are tagged. Fish are also caught at an upper fish station where the proportion of tagged fish is used to calculate returns. Reportedly, “this system provides more accurate and reliable data than that collected by electronic tracking systems alone” (Chief Harry Nyce, personal communication to John Corsiglia, 1986)."3

    In a similar context, the Wuikinuxv of central British Columbia identify the season's quotas for salmon not only with humans in mind but also with bears. They recognize that not only are the bears an important part of their ecosystem and culture but, if the bears are well-fed with salmon, they are less likely to seek out food in areas where humans live. The forest and other inhabitants that the Wuikinuxv rely on are nourished in one way or another by the remains of the salmon.2

    "The Wuikinuxv calculate fishing quotas based on salmon availability and existing bear density, assuming that, as salmon populations recover, the bear population will grow until it is limited by some other factor. Salmon and bear numbers are then balanced against the benefits of salmon to human fishers. Spawning targets aim to balance the costs felt by humans and bears, the latter of which encompasses the needs of other beings in the ecosystem. In contrast, Canada manages salmon at the federal level, while bears are managed provincially, making holistic management difficult. The smaller, more intimate scale of Indigenous management efforts, in contrast, allows closer observation of the landscape...and demonstrates how local knowledge is often undervalued".2

    "In a decolonized approach to conservation, the observations of people living in the area would be given proper respect, and systems would be in place to incorporate those observations into models. Another step toward decolonizing for settler governments to work with Indigenous communities as equals rather than as just one of many stakeholders. Resource stewardship should be inseparable from Indigenous sovereignty, assert the study’s authors."2

    In this 2.5-minute video, you will meet Kasey Stirling, a Nlaka’pamux, Mi’kmaq, and Acadienne researcher, is a master’s student in the Centre for Indigenous Fisheries at the Institute for the Oceans and Fisheries (IOF). Stirling works in partnership with the First Nations Fisheries Legacy Fund, a collective of six Lower Fraser First Nations (Katzie, Kwantlen, Kwikwetlem, Musqueam, Tsleil-Waututh, and Tsawwassen), to co-develop a more culturally relevant framework for watershed health assessment, which directly impacts salmon populations.

    Question after watching: What might be gained from scientists working in partnership with Indigenous communities to preserve diversity? What type of knowledge and perspective can each group bring to the partnership?


    Imagine the U.S. government told people who live around Yellowstone, say, all those bears and wolves are now yours to take care of, and for doing that you get to keep the money from tourists who come to see those animals. It can sound radical, but that's essentially what the government of Namibia is doing right now. And as a result, wildlife numbers are rising there - unlike much of Africa. 
    Question after watching:


    Namibia is home to around 3,500 cheetahs, or half the world's cheetah population. But the animals there are threatened by farmers, who often shoot them on sight to defend their herds. To protect the big cats, one wildlife sanctuary had the idea of ​​training sheepdogs.
    Question after watching: 

    Adapting to and Mitigating Climate Change

    More on climate change was discussed in Unit 6, but it should be clear to anyone that climate change has the potential to greatly restructure the world’s ecosystems, ecosystem services, and national economies. Many coastal areas will experience rising sea levels and increased flooding, while inland areas may experience desertification and less favorable growing conditions for crops. Poorer countries and communities will suffer the consequences disproportionately because of their limited mobility, high dependence on ecosystem services, and general lack of disaster management infrastructure.

    If we are to mitigate the far-reaching impacts of climate change, we must carefully monitor and study changes in biological communities and ecosystem functioning, and how they relate to changes in climate and other stressors. While we may lose some species in a warmer world, we can also prevent many extinctions with proactive wildlife management. It is likely that many existing protected areas will no longer preserve some of the rare and threatened species that currently live in them, necessitating careful planning when establishing new protected areas. Even if climate change is not as severe as predicted, the steps we take now to safeguard biodiversity can only help in the future.

    The widespread and dramatic impacts of climate change rightfully deserve much attention. But it is also important to remember that we continue to destroy habitats at a massive scale and increasing pace and this loss of habitat is currently the main cause of species extinctions. The highest priorities for conservation must continue to be the preservation of healthy, intact, and connected ecosystems, and the restoration of degraded ecosystems. These actions will simultaneously reduce the impacts of climate change, by reducing carbon emissions, increasing carbon sequestration, and giving wildlife more opportunities to adjust their ranges, in their own time, as the world’s climate changes.


    Indigenous communities in British Columbia are preparing for climate change, as detailed in this 5-minute video. 
    Question after watching: How are Indigenous communities reconnecting to the land in a changing climate? What other strategies are they utilizing internally and sharing with non-Indigenous communities?

    Conservation in Preserves


    This 10-minute video by Hank Green provides an overview of both conservation science and restoration efforts, described in further detail below. 
    Question after watching: What conserved spaces are nearest to you? Do you visit them? Do you know of any restoration efforts near where you live? 

    The establishment of wildlife and ecosystem preserves is one of the key tools in conservation efforts (Figure \(\PageIndex{2}\)). A preserve is an area of land set aside with varying degrees of protection for the organisms that exist within the boundaries of the preserve. Preserves can be effective in the short term for protecting both species and ecosystems, but they face challenges that scientists are still exploring to strengthen their viability as long-term solutions. Human behavior can still be problematic in these areas as well. For example, the public's misbehavior at national parks has become an increasing problem for governments in many countries. 

    Figure \(\PageIndex{2}\): National parks, such as Kootenay National Park in British Columbia, help conserve biodiversity. (Parks Canada)


    This 3-minute video from the National Resources Defense Council profiles the importance of Canada's boreal forest and current threats to this ecosystem.
    Question after watching: What strategies might be used to preserve these habitats?

    US Preservation

    An important human-centered benefit of undeveloped land is their recreational value. Every year, millions of people visit recreational lands such as parks and wilderness areas to experience attractions of the great outdoors: hiking among the giant sequoias in California, traveling on a photo safari in Kenya or just picnicking at a local county park. Besides providing people with obvious health benefits and aesthetic pleasures, recreational lands also generate considerable tourist money for government and local economies.

    The United States has set aside more land for public recreational use than any other country. Several different federal organizations provide lands for recreational use: the National Forest System, the U.S. Fish and Wildlife Service, the National Park System and the National Wilderness Preservation System. The National Forest System manages more than 170 forestlands and grasslands, which are available for activities such as camping, fishing, hiking and hunting.

    The U.S. Fish and Wildlife Service manage more than 500 National Wildlife Refuges, which not only protect animal habitats and breeding areas but also provide recreational facilities. The National Park System manages more than 380 parks, recreation areas, seashores, trails, monuments, memorials, battlefields and other historic sites. The National Wilderness Preservation System manages more than 630 roadless areas through the aforementioned government services as well as through the Bureau of Land Management.

    The National Park System consists of more than 80 million acres nationwide. The largest national park is Wrangell-St. Elias National Park and Preserve in Alaska with over 13 million acres. California has eight national parks: Channel Islands, Death Valley, Joshua Tree, Lassen, Redwood, Sequoia, Kings Canyon and Yosemite. Many national parks such as Yosemite, Yellowstone and the Grand Canyon are such popular recreation destinations that the ecosystems of those parks are being severely tested by human activities.

    In addition to their primary goal of conserving biodiversity, most parks serve additional purposes, including the support of economically important outdoor recreation and tourism. To some degree, the use of parks for these purposes is a challenge to their ability to function as ecological reserves. For example, strictly interpreted, the ecological values of national parks are not compatible with consumptive uses of their natural resources (such as sport fishing) or with the development of infrastructure to support recreation and tourism (such as campgrounds, golf courses, hotels, roads, ski facilities, and even interpretation facilities).

    Every state has also set aside significant amounts of land for recreational use. The California State Park System manages more than one million acres of parklands including: coastal wetlands, estuaries, scenic coastlines, lakes, mountains and desert areas. California's largest state park is Anza-Borrego Desert State Park, which is the largest state park in the United States with 600,000 acres. The stated mission of the California State Park System is: "To provide for the health, inspiration and education of the people of California by helping to preserve the state's extraordinary biological diversity, protecting its most valued natural and cultural resources and creating opportunities for high-quality outdoor recreation."

    This is the basic goal of all recreational lands: to manage and conserve natural ecosystems, while supporting a sustainable and balanced level of human use of those areas. Unfortunately, it is a goal which is sometimes difficult to achieve due to the increasing popularity and use of recreational lands.

    The "Wilderness Act of 1964" created the world's first wilderness system in the United States. Presently, the National Wilderness Preservation System contains more than 100 million acres of land that will forever remain wild. A wide range of recreation, scientific and outdoor activities are available in wilderness lands. Mining operations and livestock grazing are permitted to continue in certain wilderness areas where such operations existed prior to an area's designation. Hunting and fishing are also allowed in wilderness areas (except in national parks).

    For most people, wilderness lands provide a means for various forms of recreation: hiking, horseback riding, bird watching, fishing, and hunting. People can escape the stress of modern-day life and enjoy an undisturbed look at nature. Wilderness lands provide an essential habitat for a wide array of fish, wildlife, and plants, and are particularly important in protecting endangered species. For scientists, wilderness lands serve as natural laboratories, where studies can be performed that would not be possible in developed areas.

    Several other types of public lands complement the designated wilderness land system. These include: national forest roadless areas, national trails system, natural research areas and state and private wilderness lands. The national forest roadless areas consist of millions of acres of wild, undeveloped land without roads that exist on National Forest land outside of designated wilderness lands.

    The "National Trail System," established by Congress in 1968, includes trails in wilderness areas and other public lands. Research Natural Areas located throughout the country on public lands serve as outdoor laboratories to study natural systems. They are intended in part to serve as gene pools for rare and endangered species and as examples of significant natural ecosystems. Some wilderness lands are maintained by states or private organizations. For example, the state of New York has long preserved a region of the Adirondacks as wilderness.

    In addition to their primary goal of conserving biodiversity, most parks serve additional purposes, including the support of economically important outdoor recreation and tourism. To some degree, the use of parks for these purposes is a challenge to their ability to function as ecological reserves. For example, strictly interpreted, the ecological values of national parks are not compatible with consumptive uses of their natural resources (such as sport fishing) or with the development of infrastructure to support recreation and tourism (such as campgrounds, golf courses, hotels, roads, ski facilities, and even interpretation facilities).

    The ecological-reserve function of many protected areas is also threatened by land-use and management activities that are occurring in their surrounding area. Usually, the most important of the “external” stressors are associated with agriculture, forestry, mining, tourism, or hydroelectric development. In fact, all of the national parks in more southern regions of Canada are significantly threatened in this way. 

    Banff National Park in southwestern Alberta was the first national park to be established in Canada, in 1885. The original intent was to protect extremely scenic views and hot springs and to develop the area in support of the economic benefits of tourism. It was not until several decades later that the philosophical underpinning of national parks shifted toward the protection of natural values. In any event, the early development of Banff featured the enthusiastic construction of large hotels, golf courses, skiing facilities, major highways, a transcontinental railroad, several villages, and other structures. This pattern continues today with much ongoing construction, coupled with rapid development of the area east of the park for tourism, residential neighborhoods, forestry, and other uses. These facilities severely threaten the long-term viability of the natural values of Banff.

    Provincial and territorial governments also have a responsibility to protect natural values within their jurisdiction. These governments have designated many ecological reserves and wilderness areas, supplemented by natural areas that are protected in provincial parks and conservation areas, which are also well-used for recreation. Some municipalities also have natural-area parks that provide habitat for native species. An outstanding example is the city of Windsor, Ontario, which is protecting important remnants of tall-grass prairie and Carolinian forest, and their many species-at-risk.

    How Much Area to Preserve?

    Due to the way protected lands are allocated (they tend to contain less economically valuable resources rather than being set aside specifically for the species or ecosystems at risk) and the way biodiversity is distributed, determining a target percentage of land or marine habitat that should be protected to maintain biodiversity levels is challenging. The IUCN World Parks Congress estimated that 11.5% of Earth’s land surface was covered by preserves of various kinds in 2003. This area is greater than previous goals; however, it only represents 9 out of 14 recognized major biomes. Research has shown that 12% of all species live only outside preserves; these percentages are much higher when only threatened species and high-quality preserves are considered. For example, high-quality preserves include only about 50% of threatened amphibian species. The conclusion must be that either the percentage of area protected must increase, the percentage of high-quality preserves must increase, or preserves must be targeted with greater attention to biodiversity protection. Researchers argue that more attention to the latter solution is required.

    A biodiversity hotspot is a conservation concept developed by Norman Myers in 1988. Hotspots are geographical areas that contain high numbers of endemic species. The purpose of the concept was to identify important locations on the planet for conservation efforts, a kind of conservation triage. Protecting hotspots would be able to protect a larger number of species. The original criteria for a hotspot included the presence of 1,500 or more species of endemic plants and 70 percent of the area disturbed by human activity. While many have still not been conserved, there are now 34 identified global biodiversity hotspots (Figure \(\PageIndex{3}\)) that contain large numbers of endemic species, which include half of Earth’s endemic plants. In addition to natural spaces, there are numerous human cultural sites preserved in the UNESCO World Heritage Sites list:

    Figure \(\PageIndex{3}\). Conservation International has identified 34 biodiversity hotspots. Although these cover only 2.3 percent of the Earth’s surface, 42 percent of the terrestrial vertebrate species and 50 percent of the world’s plants are endemic to those hotspots.

    Optional Activity \(\PageIndex{2}\)

    Scientists are evaluating an island ecosystem for consideration as a biodiversity hotspot. What information should they collect and evaluate as part of their fieldwork to produce their final assessment?

    1. the total number of endemic species in an ecosystem
    2. the total number of organisms in an ecosystem
    3. the total number of species divided by the area of the ecosystem
    4. the total number of endangered species in an ecosystem

    A. the total number of endemic species in an ecosystem.

    Preserve Design

    There has been extensive research into optimal preserve designs for maintaining biodiversity. The fundamental principle behind much of the research has been the seminal theoretical work of Robert H. MacArthur and Edward O. Wilson published in 1967 on island biogeography.1 This work sought to understand the factors affecting biodiversity on islands. The fundamental conclusion was that biodiversity on an island was a function of the origin of species through migration, speciation, and extinction on that island. Islands farther from the mainland are harder to get to, so migration is lower and the equilibrium number of species is lower. Within island populations, evidence suggests that the number of species gradually increases to a level similar to the numbers on the mainland from which the species is suspected to have migrated. In addition, smaller islands are harder to find, so their immigration rates for new species are lower. Smaller islands are also less geographically diverse so there are fewer niches to promote speciation. And finally, smaller islands support smaller populations, so the probability of extinction is higher.

    As islands get larger, the number of species accelerates, although the effect of island area on species numbers is not a direct correlation. Conservation preserves can be seen as “islands” of habitat within “an ocean” of non-habitat. For a species to persist in a preserve, the preserve must be large enough. The critical size depends, in part, on the home range that is characteristic of the species. A preserve for wolves, which ranges hundreds of kilometers, must be much larger than a preserve for butterflies, which might range within ten kilometers during its lifetime. But larger preserves have more core area of optimal habitat for individual species, they have more niches to support more species, and they attract more species because they can be found and reached more easily.

    Preserves perform better when there are buffer zones around them of suboptimal habitat. The buffer allows organisms to exit the boundaries of the preserve without immediate negative consequences from predation or lack of resources. One large preserve is better than the same area of several smaller preserves because there is more core habitat unaffected by edges. For this same reason, preserves in the shape of a square or circle will be better than a preserve with many thin “arms.” If preserves must be smaller, then providing wildlife corridors between them so that individuals and their genes can move between the preserves, for example along rivers and streams, will make the smaller preserves behave more like one large one. All of these factors are taken into consideration when planning the nature of a preserve before the land is set aside.

    In addition to the physical, biological, and ecological specifications of a preserve, there are a variety of policy, legislative, and enforcement specifications related to the uses of the preserve for functions other than the protection of species. These can include anything from timber extraction, mineral extraction, regulated hunting, human habitation, and non-destructive human recreation. Many of these policy decisions are made based on political pressures rather than conservation considerations. In some cases, wildlife protection policies have been so strict that subsistence-living Indigenous populations have been forced from ancestral lands that fell within a preserve. In other cases, even if a preserve is designed to protect wildlife, if the protections are not or cannot be enforced, the preserve status will have little meaning in the face of illegal poaching and timber extraction. This is a widespread problem with preserves in areas of the tropics.

    Optional Activity \(\PageIndex{3}\)

    A preserve design is proposed for a densely populated suburban area. Which overall design plan would be best for preservation of local ecosystems?

    1. Set up many, small, unconnected, protected areas.
    2. Select one, small area that is isolated from residences.
    3. Plan buffer zones around all backyard spaces.
    4. Set up several, connected, larger areas to be set aside for natural ecosystems.

    D. Set up several, connected, larger areas to be set aside for natural ecosystems.

    Limitations on Preserves

    Some of the limitations of preserves as conservation tools are evident from the discussion of preserve design. Political and economic pressures typically make preserves smaller, never larger, so setting aside areas that are large enough is difficult. If the area set aside is sufficiently large, there may not be sufficient area to create a buffer around the preserve. In this case, an area on the outer edges of the preserve inevitably becomes a riskier suboptimal habitat for the species in the preserve. Enforcement of protections is also a significant issue in countries without the resources or political will to prevent poaching and illegal resource extraction.

    Climate change will create inevitable problems with the location of preserves. The species within them will migrate to higher latitudes as the habitat of the preserve becomes less favorable. Scientists are planning for the effects of global warming on future preserves and striving to predict the need for new preserves to accommodate anticipated changes to habitats; however, the end effectiveness is tenuous since these efforts are prediction-based.

    Finally, an argument can be made that conservation preserves reinforce the cultural perception that humans are separate from nature, can exist outside of it, and can only operate in ways that do damage to biodiversity. Creating preserves reduces the pressure on human activities outside the preserves to be sustainable and non-damaging to biodiversity. Ultimately, the political, economic, and human demographic pressures will degrade and reduce the size of conservation preserves if the activities outside them are not altered to be less damaging to biodiversity.

    Habitat Restoration

    Habitat restoration holds considerable promise as a mechanism for restoring and maintaining biodiversity. Of course, once a species has become extinct, its restoration is impossible. However, restoration can improve the biodiversity of degraded ecosystems. Reintroducing wolves, a top predator, to Yellowstone National Park in 1995 led to dramatic changes in the ecosystem that increased biodiversity (Figure \(\PageIndex{4}\)).

    The wolves, a keystone species, function to suppress elk and coyote populations and provide more abundant resources to the guild of carrion eaters. Reducing elk populations has allowed the revegetation of riparian areas, which has increased the diversity of species in that habitat. Decreasing the coyote population has increased the populations of species that were previously suppressed by this predator. The number of species of carrion eaters has increased because of the predatory activities of the wolves.

    The results from the Yellowstone experiment suggest that restoring a keystone species can have the effect of restoring biodiversity in the community. Ecologists have argued for the identification of keystone species where possible and for focusing protection efforts on those species; likewise, it also makes sense to attempt to return them to their ecosystem if they have been removed.

    Photo A shows a pack of wolves walking on snow. Photo B shows an elk. Photo C shows a river running through a meadow with a few copses of trees, some living and some dead. Photo D shows a beaver.
    Figure \(\PageIndex{4}\): (a) The Gibbon wolf pack in Yellowstone National Park, March 1, 2007, represents a keystone species. The reintroduction of wolves into Yellowstone National Park in 1995 led to a change in the grazing behavior of (b) elk. To avoid predation, the elk no longer grazed exposed stream and riverbeds, such as (c) the Lamar Riverbed in Yellowstone. This allowed willow and cottonwood seedlings to grow. The seedlings decreased erosion and provided shading to the creek, which improved fish habitat. A new colony of (d) beaver may also have benefited from the habitat change. (credit a: modification of work by Doug Smith, NPS; credit c: modification of work by Jim Peaco, NPS; credit d: modification of work by “Shiny Things”/Flickr)

    Other large-scale restoration experiments underway involve dam removal. Since the mid-1980s, many aging dams are being considered for removal rather than replacement because of shifting beliefs about the ecological value of free-flowing rivers and because many dams no longer provide the benefit and functions that they did when they were first built. The measured benefits of dam removal include restoration of naturally fluctuating water levels (the purpose of dams is frequently to reduce variation in river flows), which leads to increased fish diversity and improved water quality.

    On the Pacific coast, dam removal projects are expected to increase populations of salmon, which is considered a keystone species because it transports key nutrients to inland ecosystems during its annual spawning migrations. In other regions such as the Atlantic coast, dam removal has allowed the return of other spawning anadromous fish species (species that are born in freshwater, live most of their lives in salt water, and return to freshwater to spawn). Some of the largest dam removal projects have yet to occur or have happened too recently for the consequences to be measured. The large-scale ecological experiments that these removal projects constitute will provide valuable data for other dam projects slated either for removal or construction.


    This 2.5-minute video highlights the work to create and restore vital habitat for pacific salmon in the Upper Pitt watershed in B.C., on the unceded territory of the Katzie First Nation.
    Question after watching: How did the members restore the habitat and why were these efforts good for the salmon?

    The Role of Zoos and Aquariums in Conservation

    Zoos and aquariums have sought to play a role in conservation efforts both through captive breeding programs and education (Figure \(\PageIndex{5}\)). The transformation of the missions of zoos and aquariums from collection and exhibition facilities to organizations that are dedicated to conservation is ongoing. In general, it has been recognized that, except in some specifically targeted cases, captive breeding programs for endangered species are inefficient and often prone to failure when the species are reintroduced to the wild. These facilities are far too limited to contemplate captive breeding programs for the number of species that are now at risk. Education, on the other hand, is a potential positive impact of zoos and aquariums on conservation efforts, particularly given the global trend to urbanization and the consequent reduction in contact between people and wildlife. A number of studies have been performed to look at the effectiveness of these facilities on people’s attitudes and actions regarding conservation and at present, the results tend to be mixed.

    Figure \(\PageIndex{5}\). Zoos and captive breeding programs have helped to preserve many endangered species, such as the golden lion tamarin. (credit: Garrett Ziegler)


    This 3-minute video from PBL Netherlands Environmental Assessment Agency brings you to the year 2050 and shows you the future is not fixed: choices we, as society, make today will determine what the world will look like in decades' time.
    Question after watching: Which choices have the biggest impacts? Are those choices on the individual or societal level?


    1. Reid, A.J. et al. 2020. “Two-Eyed Seeing”: An Indigenous framework to transform fisheries research and management. Fish and Fisheries. 22(2): 243-261.

    2. Gies, E. April 25, 2022. How to decolonize conservation. Hakai Magazine [Online]. Available from:

    3. Snively, G. and Corsiglia, J. 2016. Indigenous science: Proven, practical and timeless. Chapter 6 in: Knowing home: Braiding Indigenous Science with Western Science, Book  1. Eds: G. Snively and W.L. Williams. 

    This page titled 22.4: Preserving Biodiversity is shared under a CC BY-SA 4.0 license and was authored, remixed, and/or curated by Tara Jo Holmberg.