Habitat destruction is a process in which natural habitats can not support existing species. In this process, organisms that previously used the site were displaced or destroyed, reducing biodiversity. Habitat destruction by human activities primarily for the purpose of harvesting natural resources for industrial production and urbanization. Clearing habitats for agriculture is a major cause of habitat destruction. Other important causes of habitat destruction include mining, logging, trawling and urban dissemination. Habitat destruction is currently classified as a major cause of extinction of species worldwide. It is a process of changing the natural environment that may be caused by habitat fragmentation, geological processes, climate change or by human activities such as the introduction of invasive species, ecosystem nutrient depletion, and other human activities.
The terms habitat loss and habitat reduction are also used in a broader sense, including habitat loss from other factors, such as water and sound pollution.
Video Habitat destruction
Impact on organism
In the simplest terms, when habitats are destroyed, plants, animals, and other organisms that occupy the habitat have reduced carrying capacity so that populations decline and extinctions become more likely. Perhaps the greatest threat to organisms and biodiversity is the process of habitat loss. Temple (1986) found that 82% of endangered bird species are significantly threatened by habitat loss. Most amphibian species are also threatened by habitat loss, and some species now only breed in modified habitats. Endemic organisms with limited ranges are most affected by habitat destruction, especially since these organisms are not found elsewhere in the world and thus, have little chance of recovery. Many endemic organisms have very specific requirements for their survival that can only be found in certain ecosystems, resulting in their extinction. Extinction can also occur very long after the destruction of habitat, a phenomenon known as debt extinction. Habitat destruction can also decrease the population of certain organisms. This can lead to reduced genetic diversity and possibly the production of infertile young children, as these organisms will have a higher probability of mating with related organisms in their populations, or different species. One of the most notable examples is the impact of China's giant panda, which has been found all over the country. It is now found only in fragmented and isolated areas of the country's southwest, as a result of widespread deforestation in the 20th century.
Maps Habitat destruction
Geography
Biodiversity hotspots are tropical regions with high concentrations of endemic species and, when all hotspots are combined, may contain more than half of the world's terrestrial species. This hot spot suffers from habitat loss and destruction. Most of the natural habitats on the island and in areas with high human population densities have been destroyed (WRI, 2003). The islands that suffer extreme habitat destruction include New Zealand, Madagascar, Philippines, and Japan. South and East Asia - primarily China, India, Malaysia, Indonesia, and Japan - and many areas of West Africa have a very dense human population that allows less space for natural habitats. The marine areas close to densely populated coastal cities also face the degradation of coral reefs or other marine habitats. These areas include the east coast of Asia and Africa, the north coast of South America, and the Caribbean Sea and its associated islands.
Unsustainable agricultural areas or unstable governments, which may go side by side, typically experience high levels of habitat destruction. Central America, Sub-Saharan Africa, and the Amazon rainforest areas of South America are key areas with unsustainable agricultural practices and/or government mismanagement.
High agricultural yields tend to have the highest rates of habitat destruction. In the US, less than 25% of the original vegetation remains in much of the East and Central West. Only 15% of the land area remains unmodified by human activity across Europe.
Ecosystem
Tropical rain forests have received the most attention to habitat destruction. Of the approximately 16 million square kilometers of tropical rain forest habitat that originally existed worldwide, less than 9 million square kilometers still exist today. The current deforestation rate is 160,000 square kilometers per year, which is equivalent to a loss of about 1% of the original forest habitat each year.
Other forest ecosystems have suffered as much destruction as tropical rain forests. Agriculture and logging have greatly disturbed at least 94% of the broadleaf forest; many old growth forest stands have lost more than 98% of the previous area due to human activity. Dry tropical dry forests are easier to clean and burn and more suitable for agriculture and livestock than tropical rainforests; consequently, less than 0.1% of dry forests on the Pacific Coast of Central America and less than 8% in Madagascar remain from their original extents.
The terrain and desert areas have been degraded to a lesser extent. Only 10-20% of the world's dryland, which includes temperate pastures, savannahs, shrubs, bushes, and deciduous forests, has been slightly degraded. But included in 10-20% of the land is about 9 million square kilometers of seasonal dry land that converts humans into deserts through desertification processes. Tallgrass grassland in North America, on the other hand, has less than 3% of the remaining natural habitat that has not been converted to agricultural land.
Wetlands and marine areas have experienced high levels of habitat destruction. More than 50% of wetlands in the US have been destroyed in just the last 200 years. Between 60% and 70% of Europe's wetlands have been completely destroyed. In the UK, there has been an increase in demand for coastal housing and tourism that has led to a decline in marine habitats over the last 60 years. Rising sea levels and temperatures have caused soil erosion, coastal flooding, and loss of quality of marine ecosystems in the UK. About one fifth (20%) of coastal areas have been highly modified by humans. One fifth of the coral reefs have also been destroyed, and another fifth have been severely degraded by overfishing, pollution, and invasive species; 90% of the Philippine coral reef alone has been destroyed. Finally, more than 35% of mangrove ecosystems around the world have been destroyed.
Natural causes
Habitat destruction through natural processes such as volcanism, fires, and climate change is well documented in the fossil record. One study showed that fragmentation of tropical rainforest habitat in Euramerica 300 million years ago led to a loss of amphibian diversity, but simultaneously a drier climate spurred the explosion of diversity among reptiles.
Human cause
Destruction of habitats caused by humans including land conversion from forests, etc. To fertile land, urban spread, infrastructure development, and other anthropogenic changes to land characteristics. Degradation Habitat, fragmentation, and pollution are aspects of habitat-induced destruction that do not always involve habitat destruction, but lead to habitat destruction. Desertification, deforestation and degradation of coral reefs is a type of habitat destruction specifically for these areas (deserts, forests, coral reefs).
Geist and Lambin (2002) assessed 152 case studies of net loss of tropical forest cover to determine any pattern in the direct and underlying causes of tropical deforestation. Their results, generated as a percentage of case studies in which each parameter is a significant factor, gives a quantitative priority in which the nearest and underlying causes are the most significant. The nearest causes were grouped into broad categories of agricultural expansion (96%), infrastructure expansion (72%), and wood extraction (67%). Therefore, according to this study, conversion of forests to agriculture is a major land use change responsible for tropical deforestation. Specific categories reveal more about specific causes of tropical deforestation: transport extension (64%), commercial timber extraction (52%), permanent cultivation (48%), livestock (46%), shifting cultivation (slash and burn) (41%) , subsistence farming (40%), and extraction of firewood for domestic use (28%). One result is that shifting cultivation is not the main cause of deforestation in all regions of the world, while the expansion of transport (including the construction of new roads) is the single largest single proximate factor responsible for deforestation.
Global warming
Increased global temperatures, caused by the greenhouse effect, contribute to habitat destruction, endangering various species, such as polar bears. A melting ice cap increases sea level rise and floods that threaten natural habitats and species globally.
Driver
While the above-mentioned activities are the direct or proactive cause of habitat destruction in which they completely destroy habitat, this still does not identify why humans destroy habitat. The forces that cause humans to destroy habitats are known as drivers from habitat destruction. Demographic, economic, socio-political, scientific and technological drivers, and culture all contribute to habitat destruction.
Demographic drivers include a widespread human population; the rate of population increase over time; spatial distribution of people in certain areas (urban versus rural), ecosystem type, and country; and the combined effects of poverty, age, family planning, gender, and educational status of people in certain areas. Much of the growth of exponential human populations around the world takes place in or close to biodiversity hotspots. This may explain why the density of the human population accounts for 87.9% of the variation in the number of threatened species in 114 countries, providing undeniable evidence that people play the greatest role in reducing biodiversity. The explosion of human populations and the migration of people into species-rich areas makes conservation efforts not only more urgent but also more likely to conflict with local human interests. The high local population density in these areas is directly correlated with the poverty status of the local population, many of whom have no education and family planning.
From Geist and Lambin (2002) studies described in the previous section, underlying driving forces are prioritized as follows (with percent of the 152 case factors play an important role in): economic factors (81%), institutional or policy factors (78%), technological factors (70%), cultural or socio-political factors (66%), and demographic factors (61%). Major economic factors include commercialization and growth of the timber market (68%), driven by national and international demand; urban industrial growth (38%); low domestic costs for land, labor, fuel and wood (32%); and increase in product prices especially for commercial crops (25%). Institutional and policy factors include formal pro-deforestation policies on land development (40%), economic growth including colonization and infrastructure improvements (34%), and subsidies for land-based activities (26%); property rights and insecurity of land tenure (44%); and policy failures such as corruption, lawlessness, or mismanagement (42%). The main technological factor is the adoption of bad technology in the wood industry (45%), leading to extravagant logging practices. In the broad category of cultural and socio-political factors are public attitudes and values ​​(63%), individual/household behavior (53%), public ignorance of the forest environment (43%), loss of base value (36%), individuals (32%). The demographic factor is the inward migration of settlers who colonize the rare forest area (38%) and the ever-increasing population density - the result of the first factor - in the region (25%).
There is also feedback and interaction between the underlying and underlying causes of deforestation that can strengthen the process. Road construction has the greatest feedback effect, as it interacts with - and leads to - the formation of new settlements and more people, leading to the growth of timber (logging) and food markets. Growth in these markets, in turn, promotes the commercialization of the agricultural and logging industries. When the industry is commercialized, they must become more efficient by using larger or more modern machines that are often worse in their habitats than traditional farming and logging methods. However, more land is cleared faster for the commercial market. This general feedback example manifests how closely the link between the nearest and the underlying causes of each other.
Impact on human population
Habitat destruction greatly increases local vulnerability to natural disasters such as floods and droughts, crop failure, disease spread, and water contamination. On the other hand, healthy ecosystems with good management practices will reduce the likelihood of these events occurring, or at least will reduce adverse impacts.
Agricultural land can really spoil the landscape around it. Over the past 50 years, habitat destruction around farmland has reduced approximately 40% of agricultural land worldwide through erosion, salinization, compaction, nutrient depletion, pollution, and urbanization. Humans also lose direct use of natural habitats when habitats are destroyed. Aesthetic uses such as bird watching, recreational uses such as hunting and fishing, and ecotourism usually depend on undisturbed habitats. Many people appreciate the complexity of the natural world and are plagued by the loss of natural habitats and animals or plants around the world.
Perhaps the greatest impact of habitat destruction on humans is the loss of many valuable ecosystem services. Habitat destruction has altered nitrogen, phosphorus, sulfur, and carbon cycles, which has increased the frequency and severity of acid rain, algal blooms, and fish kills in rivers and oceans and contributes enormously to global climate change. One of the ecosystem services whose significance becomes more apparent is climate regulation. On a local scale, trees provide windbreaks and shadows; on a regional scale, crop transpiration recycles rainwater and maintains a constant annual rainfall; on a global scale, plants (especially trees from tropical rainforest) from around the world against the accumulation of greenhouse gases in the atmosphere by sequestering carbon dioxide through photosynthesis. Other ecosystem services that disappear or disappear altogether as a result of habitat destruction include watershed management, nitrogen fixation, oxygen production, pollination (see pollinator decrease), waste treatment (ie, discontinuation and immobilization of toxic pollutants), and recycling of waste or runoff nutrients agriculture.
The loss of trees from tropical rainforests alone is the loss of the Earth's ability to produce oxygen and deplete carbon dioxide. This service is becoming increasingly important as increases in carbon dioxide levels are one of the major contributors to global climate change.
Loss of biodiversity may not directly affect humans, but the indirect effects of losing many species and the diversity of ecosystems are generally very large. When biodiversity is lost, the environment loses many species that provide a valuable and unique role to the ecosystem. The environment and all its inhabitants depend on biodiversity to recover from extreme environmental conditions. When too much biodiversity is lost, catastrophic events such as earthquakes, floods, or volcanic eruptions can cause the ecosystem to fall, and people will obviously suffer from it. The loss of biodiversity also means that humans lose animals that can function as biological and plant control agents that potentially provide higher crop varieties, pharmaceutical drugs to cure existing or future or cancerous diseases, and new resistant crop varieties for agricultural species the vulnerable. for insects that are resistant to pesticides or fungal strains of fungi, viruses and bacteria.
The negative effects of habitat destruction typically have an impact on rural populations more directly than urban populations. Around the world, the poor suffer most when natural habitats are destroyed, since less natural habitats mean less natural resources per capita, but rich people and countries simply have to pay more to continue receiving more of their per capita share than natural resources.
Another way to look at the negative effects of habitat destruction is to see the opportunity cost of keeping an area undisturbed. In other words, what do people lose by taking the given habitat? A country can increase its food supply by converting forest land to agricultural farming lines, but the value of the same land may be much greater when it can supply natural resources or services such as clean water, timber, ecotourism, or flood regulation and control drought.
Outlook
The rapid expansion of the global human population raises the world's food needs substantially. Simple logic instructs that more people will need more food. In fact, when the world's population increases dramatically, agricultural output needs to be increased by at least 50%, over the next 30 years. In the past, continuing to move to new land and land provided a boost in food production to meet global food demand. Such easy repairs will no longer be available, as more than 98% of all suitable land for agriculture is already used or degraded beyond repair.
The upcoming global food crisis will be a major source of habitat destruction. Commercial farmers will be desperate to produce more food from the same amount of land, so they will use more fertilizer and less environmental care to meet market demand. Others will look for new land or will convert other land uses to agriculture. Agricultural intensification will be widespread with the cost of the environment and its inhabitants. Species will be driven out of their habitat either directly by habitat destruction or indirectly by fragmentation, degradation, or pollution. Any effort to protect the world's remaining natural habitat and biodiversity will compete directly with the increasing human demand for natural resources, especially new agricultural land.
Solution
In most cases of tropical deforestation, three to four major causes drive two to three immediate causes. This means that universal policies to control tropical deforestation will not be able to address the unique combination of direct causes and causes of deforestation in each country. Prior to local, national or international deforestation policies written and enforced, government leaders should gain a detailed understanding of the complex combination of direct causes and drivers underlying deforestation in a particular region or country. This concept, along with many other results on tropical deforestation from the Geist and Lambin studies, can easily be applied to habitat destruction in general. Government leaders need to take action by addressing the underlying driving force, not just regulating the immediate cause. In a broader sense, government bodies at local, national, and international levels need to emphasize the following:
- Considering the many irreplaceable ecosystem services provided by natural habitats.
- Protects the remaining part of the remaining natural habitat.
- Educate the public about the importance of natural habitat and biodiversity.
- Develop family planning programs in areas with rapid population growth.
- Finding ecological ways to improve agricultural yields without increasing total land in production.
- Preserves habitat corridors to minimize previous damage from fragmented habitats.
- Reduce population and human expansion.
Note
References
Source of the article : Wikipedia
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