The vaquita porpoise, a small mammal that lives only in the Gulf of California, now has very few individuals left. In contrast, the jaguar and other species are recovering where their forests are protected. What happens to each species depends on specific decisions. Understanding the threats is the first step toward reversing them.
Threats to Biodiversity
In recent decades, populations of wild vertebrates around the planet have declined enormously, at an extinction rate hundreds of times higher than the natural one. Which human factors explain such a rapid loss?
Climate Change: Causes and Consequences for Biodiversity
Earth's climate is warming because human activities release more greenhouse gases into the atmosphere. These gases trap part of the heat, like a blanket around the planet. Some of that effect is natural and necessary; the problem is the excess.
The consequences for biodiversity are many. Corals become stressed in warm water and bleach, as in the Mesoamerican reef off Quintana Roo. Droughts and temperature changes alter the forests where the monarch butterfly overwinters in Michoacán. Species must move to cooler places, but if the habitat is fragmented, they do not always succeed. In addition, warming makes cyclones and droughts more intense, and these also harm people.
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Name three current threats to biodiversity and briefly explain what one of them consists of.
Name three current threats to biodiversity and briefly explain what one of them consists of.
The construction of a motorway has split a protected natural area in two, leaving a population of badgers separated into two isolated groves. Over the years,…
The construction of a motorway has split a protected natural area in two, leaving a population of badgers separated into two isolated groves. Over the years, environmental officers detect an increase in inbreeding, a lower birth rate, and frequent roadkill of individuals attempting to cross the road.
a) Justify why the isolation of these populations threatens their long-term survival, even though the original forest remains well-conserved.
b) Design a proposal based on wildlife corridors to restore connectivity between both sectors without halting motorway traffic, and predict what benefits this measure will bring to the species' migrations and genetic exchange.
Distinguish between in situ conservation (national parks and nature reserves) and ex situ conservation (zoos, seed banks, or germplasm banks), and state one advantage of…
Distinguish between in situ conservation (national parks and nature reserves) and ex situ conservation (zoos, seed banks, or germplasm banks), and state one advantage of each strategy.
When a species is harvested faster than it reproduces, its population declines. This is called overexploitation: excessive fishing, illegal hunting, or uncontrolled logging. Fishing is a good example: if all the adult fish and also the young are caught, no individuals are left to reproduce.
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Explain what overfishing is and how measures such as closed seasons or minimum catch sizes help recover fish populations.
Explain what overfishing is and how measures such as closed seasons or minimum catch sizes help recover fish populations.
The Iberian lynx population has grown from around 100 individuals to more than 2 000 in just two decades. Cite two conservation measures that have made this recovery…
The Iberian lynx population has grown from around 100 individuals to more than 2 000 in just two decades. Cite two conservation measures that have made this recovery possible and explain how one of them works.
When a road is built that cuts a pine-oak forest from one side to the other, the area cleared is less than 2%, yet years later the forest birds have disappeared from the area. Why is splitting an ecosystem into pieces so much more destructive than losing a small strip of land?
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A local municipality is planning to build a parking lot next to a lagoon where protected birds overwinter. Draft a set of arguments outlining two foreseeable impacts of…
A local municipality is planning to build a parking lot next to a lagoon where protected birds overwinter. Draft a set of arguments outlining two foreseeable impacts of the construction work and two less harmful alternatives.
Caring for biodiversity is not just the job of scientists or governments: communities, schools, and each person's decisions also count. Indigenous peoples have protected forests, milpas (traditional cornfields), and waters for centuries through practices such as crop rotation and the respectful use of medicinal plants.
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The graph shows the change in the population census of an endangered species since its recovery plan was launched. Calculate the total percentage increase between 2010…
The graph shows the change in the population census of an endangered species since its recovery plan was launched. Calculate the total percentage increase between 2010 and 2024, describe the trend, and assess whether the recovery plan is working.
Contaminated water, habitat loss, or the misuse of antibiotics do not respect the separation between the environment, animals, and people.
Go back to the beginning: the vaquita and the jaguar show that species do not save themselves. They recover when measures are combined: protecting habitat, regulating fishing, enforcing rules, reconnecting fragments, slowing warming, and working with communities.
Let's practice! 3 medium exercises in this section