Conservation of resources
Management of the human use of natural resources to provide the maximum benefit to current generations while maintaining capacity to meet the needs of future generations. Conservation includes both the protection and rational use of natural resources.
Earth's natural resources are either nonrenewable, such as minerals, oil, gas, and coal, or renewable, such as water, timber, fisheries, and agricultural crops. The combination of growing populations and increasing levels of resource consumption is degrading and depleting the natural resource base. The world's population stood at 850 million at the onset of the industrial age. The global population has grown to nearly seven times as large (6 billion), and the level of consumption of resources is far greater. This human pressure now exceeds the carrying capacity of many natural resources.
Nonrenewable resources, such as fossil fuels, are replaced over geologic time scales of tens of millions of years. Human societies will eventually use up all of the economically available stock of many nonrenewable resources, such as oil. Conservation entails actions to use these resources most efficiently and thereby extend their life as long as possible. By recycling aluminum, for example, the same piece of material is reused in a series of products, reducing the amount of aluminum ore that must be mined. Similarly, energy-efficient products help to conserve fossil fuels since the same energy services, such as lighting or transportation, can be attained with smaller amounts of fuel. See Human ecology
It may be expected that the biggest challenge of resource conservation would involve nonrenewable resources, since renewable resources can replenish themselves after harvesting. In fact, the opposite is the case. Historically, when nonrenewable resources have been depleted, new technologies have been developed that effectively substitute for the depleted resources. Indeed, new technologies have often reduced pressure on these resources even before they are fully depleted. Fiber optics, for example, has substituted for copper in many electrical applications, and it is anticipated that renewable sources of energy, such as photovoltaic cells, wind power, and hydropower, will ultimately take the place of fossil fuels when stocks are depleted. Renewable resources, in contrast, can be seriously depleted if they are subjected to excessive harvest or otherwise degraded, and no substitutes are available for, say, clean water or food products such as fish or agricultural crops. Moreover, when the misuse of biological resources causes the complete extinction of a species or the loss of a particular habitat, there can be no substitute for that diversity of life.
“Conservation” is sometimes used synonymously with “protection.” More appropriately, however, it refers to the protection and sustainable use of resources. Critical elements of the effective conservation of natural resources include sustainable resource management, establishment of protected areas, and ex situ (off-site) conservation.
Resource management
Some of the most pressing resource conservation problems stem directly from the mismanagement of important biological resources. Many marine fisheries are being depleted, for example, because of significant overcapacity of fishing vessels and a failure of resource managers to closely regulate the harvest. In theory, a renewable resource stock could be harvested at its maximum sustainable yield and maintain constant average annual productivity in perpetuity. In practice, however, fishery harvest levels are often set too high and, in many regions, enforcement is weak, with the result that fish stocks are driven to low levels. A similar problem occurs in relation to the management of timber resources. Short-term economic incentives encourage cutting as many trees as quickly as possible.
A number of steps are being taken to improve resource conservation in managed ecosystems. (1) Considerable scientific research has been undertaken to better understand the natural variability and productivity of economically important resources. (2) Many national and local governments have enacted regulations for resource management practices on public and private lands. (3) In some of regions, programs recently have been established either to involve local communities who have a greater incentive to manage for long-term production more directly in resource management decisions or to return to them resource ownership rights. (4) Efforts are under way to manage resources on a regional or ecosystem scale using methods that have come to be known as ecosystem management or bioregional management. Since the actions taken in one location often influence species and processes in other locations, traditional resource conservation strategies were often focused too narrowly to succeed.
Protected areas
One of the most effective strategies to protect species from extinction is the establishment of protected areas designed to maintain populations of a significant fraction of the native species in a region. Worldwide, 9832 protected areas, totaling more than 9.25 million square kilometers (24 million square miles), cover about 8% of land on Earth. Although these sites are not all managed exclusively for the conservation of species, they play an essential role in protecting species from extinction.
Many problems remain, however, in ensuring effective protected-area conservation networks. For example, several regions with important biodiversity still lack effective protected-area networks. In addition, where protected areas have been designated, human and financial resources are not always available to effectively manage the areas. Particularly in developing countries, the establishment of protected areas has resulted in conflicts with local communities that had been dependent upon the areas for their livelihood. These challenges are now being addressed through international efforts, such as the International Convention on Biological Diversity, which aims to increase the financing available for protected areas and to integrate conservation and development needs.
Ex situ conservation
The most effective and efficient means for conserving biological resources is to prevent the loss of important habitats and to manage resources for their long-term productivity of goods and services. In many cases, effective conservation in the field is no longer possible. For example, some species have been so depleted that only a few individuals remain in their natural habitat. In these cases, there is no alternative to the ex situ conservation of species and genetic resources in zoos, botanical gardens, and seed banks. Ex situ collections play important conservation roles as well as serving in public education and research. Worldwide, zoos contain more than 3000 species of birds, 1000 species of mammals, and 1200 species of reptiles, and botanic gardens are believed to hold nearly 80,000 species of plants. These collections hold many endangered species, some of which have breeding populations and thus could potentially be returned to the wild. Genebanks hold an important collection of the genetic diversity of crops and livestock.