APES ch 11 and 12: Forestry and Biodiversity Sustainability

forest

-A forest is any ecosystem with a high density of trees. Forests provide habitat for countless organisms; help maintain the quality of soil, air, and water; and play key roles in our planet's biogeochemical cycles. -Forests also provide humanity with wood for fuel, construction, paper production, and more.

ESA: cooperation with landowners

-A landowner and the government can agree to a habitat conservation plan, an arrangement that grants the landowner an "incidental take permit" to harm some individuals of a species if he or she voluntarily improves habitat for the species. -Similarly, in a safe harbor agreement, the government agrees not to mandate additional or different management requirements if the landowner pursues actions that assist a species' recovery.

parks and protected areas (protecting ecosystems and biodiversity)

-A prime way to conserve habitats, communities, ecosystems, and landscapes is to set aside areas of undeveloped land to be protected in parks and preserves. -Some preserves are privately owned -Most protected areas are publicly owned and managed. Currently we have set aside 13% of the world's land area in national parks, state parks, provincial parks, wilderness areas, biosphere reserves, and other protected areas. -offer animals and plants a degree of protection from human persecution, and some are large enough to preserve entire natural systems that otherwise would be fragmented, degraded, or destroyed. -Alas, setting aside land is not always enough to ensure effective conservation: can travel outside of it and get killed

forests ecosystem services

-As plants grow, their roots stabilize the soil and help to prevent erosion. -Trees' roots draw minerals up from deep soil layers and deliver them to surface soil layers where other plants can use them. -Plants also return organic material to the topsoil when they die or drop their leaves. -When rain falls, leaves and leaf litter slow runoff by intercepting water. -Forest plants also filter pollutants and purify water as they take it up from the soil and release it to the atmosphere in transpiration. -Plants draw carbon dioxide from the air for use in photosynthesis, release the oxygen that we breathe, and regulate moisture and precipitation. -Forests also enhance our health and quality of life by providing us with cultural, aesthetic, and recreation values.

climate change and biodiversity

-As we warm the atmosphere with emissions of greenhouse gases from fossil fuel combustion, we modify long-term climate patterns and we increase the frequency of extreme weather events (such as droughts and storms) that put stress on populations. -In the Arctic, where temperatures have warmed the most, melting sea ice and other impacts are threatening polar bears and people alike. -Across the world, warming temperatures are forcing many organisms to shift their geographic ranges toward the poles and higher in altitude. -Some species will not be able to adapt. -As ranges shift, animals and plants encounter new communities of prey, predators, and parasites to which they are not adapted. -All in all, scientists predict that a rise in global temperature of 1.5-2.5°C (2.7-4.5°F) could put 20-30% of the world's plants and animals at increased risk of extinction.

umbrellas and flagships (protecting ecosystems and biodiversity)

-As with endangered species under the ESA, particular species can often serve as tools to conserve habitats, communities, and ecosystems. -Such species are called umbrella species because they act as a kind of umbrella to protect many others. -Umbrella species often are large animals that roam great distances -Because such animals require large areas, meeting their habitat needs helps meet those of thousands of less charismatic animals, plants, and fungi that might never elicit as much public interest.

HIPPCO - habitat loss

-Because organisms have adapted to their habitats over thousands or millions of years of evolution, any sudden, major change in their habitat will likely render it less suitable for them. -destroyed outright, but also when they are altered through more subtle processes, including fragmentation and other forms of degradation. -Urban sprawl supplants diverse natural ecosystems, driving many species from their homes. -Grazing modifies the structure and species composition of grasslands, and can lead to desertification. -Habitat loss affects nearly every biome. More than half of the world's temperate forests, grasslands, and shrublands had been converted by 1950 (mostly for agriculture).

forests worsen climate change

-Because trees absorb carbon dioxide from the air during photosynthesis and then store carbon in their tissues, forests serve as a major reservoir for carbon. -When plant matter is burned or when plants die and decompose, carbon dioxide is released-and thereafter less vegetation remains to soak it up. -Carbon dioxide is the primary greenhouse gas contributing to global climate change. -Therefore, when we destroy forests, we accelerate climate change.

seed-tree approach

-Clear-cutting remains the most widely practiced method, but alternative approaches involve cutting some trees while leaving others standing. -In the seed-tree approach, small numbers of mature and vigorous seed-producing trees are left standing so that they can reseed the logged area. -even aged trees

deforestation in North America

-Deforestation for timber and farmland propelled the expansion of the United States and Canada westward across the North American continent. -The vast deciduous forests of the East were cleared by the mid-1800s, making way for countless small farms. -Timber from these forests built the cities of the Atlantic seaboard. -As a farming economy shifted to an industrial one, wood was used to stoke the furnaces of industry. -Once mature trees were removed from these areas, timber companies moved west -Exploiting forest resources helped American society to develop, but we were not harvesting forests sustainably. -Instead, we were depleting our store of renewable resources for the future.

concession

-Developing nations often are desperate enough for economic development and foreign capital that they impose few restrictions on logging. -Often they allow their timber to be extracted by foreign multinational corporations, which pay fees for a concession, or right to extract the resource. -Once a concession is granted, the corporation has little or no incentive to manage forest resources sustainably. -Local people may receive temporary employment from the corporation, but once the timber is gone they no longer have the forest and the ecosystem services it provided.

poaching

-Elephant numbers recovered following the ban, but since 2007 poaching (the illegal killing of wildlife for meat or body parts) has increased to all-time highs, driven by high black-market prices for ivory paid by wealthy overseas buyers. -overharvesting -Rhinoceros populations have crashed as poachers slaughter rhinos for their horns, which are ground into powder and sold to ultra-wealthy Asian consumers as cancer cures, party drugs, or hangover treatments, even though the horns have no such properties and consist of the same material as our fingernails.

Endangered Species Act

-Enacted in 1973, the Endangered Species Act (ESA) offers protection to species that are judged to be endangered (in danger of becoming extinct in the near future) or threatened (likely to become endangered soon). -The ESA forbids the government and private citizens from taking actions that destroy individuals of these species or the habitats that are critical to their survival. The ESA also forbids trade in products made from threatened and endangered species. -The AIM is to prevent extinctions and enable declining populations to recover. -For every listed species that has gone extinct, three have recovered enough that they have been removed from the endangered species list. -today a number of species are judged by scientists to be in need of ESA protection but have not been added to the endangered species list because government funding is inadequate to help recover them.

fire suppression

-For more than a century, the Forest Service and other agencies suppressed fire whenever and wherever it broke out. -Yet scientific research clearly shows that many species and ecological communities depend on fire. -Some plants have seeds that germinate only in response to fire, and researchers studying tree rings have documented that North America's grasslands and pine woodlands burned frequently. -ecosystems dependent on fire are adversely affected when fire is suppressed: Grasslands are invaded by shrubs, and pine woodlands become cluttered with hardwood understory. -Invasive plants move in, and animal diversity and abundance decline. -Over time, suppressing frequent low-intensity fires leads to occasional catastrophic fires as because fire suppression allows limbs, logs, sticks, and leaf litter to accumulate on the forest floor, producing kindling for a catastrophic fire. -At the same time, increased residential development alongside forested land—in the wildland-urban interface—is placing more homes in fire-prone situations.

genetic diversity

-Genetic diversity encompasses the differences in DNA composition among individuals, and these differences provide the raw material for adaptation to local conditions. -In the long term, populations with more genetic diversity may be more likely to persist, because their variation better enables them to cope with environmental change.

climate change and pest outbreaks: forests

-Global climate change is now worsening wildfire risk by bringing warmer weather to North America and drier weather to the American West. -Scientific climate models predict further warming and drying. -Pest insects such as bark beetles, which feed within the bark of conifer trees, are adding to the wildfire risk. -These beetles attract one another to weakened trees and attack en masse, eating tissue, laying eggs, and bringing with them a small army of fungi, bacteria, and other pathogens. -Bark beetle infestations can wipe out vast areas of trees with amazing speed. -Since the 1990s, beetle outbreaks have been killing tens of billions of conifer trees and leaving them as fodder for fires. -Already many dense, moist forests devastated by beetles have been replaced by drier woodlands, shrublands, or grasslands.

habitat fragmentation

-Habitat loss occurs most commonly through gradual, piecemeal degradation, such as habitat fragmentation. -When farming, logging, road building, or development intrude into an unbroken expanse of forest or grassland, this breaks up a continuous area of habitat into fragments, or patches. -As habitat fragmentation proceeds across a landscape, animals and plants requiring the habitat disappear from one fragment after another. -Fragmentation can also prevent animals from moving from place to place -In response to habitat fragmentation, conservationists try to link fragments together with corridors of habitat along which animals can travel. -TOP reason for biodiversity decline

canopy

-In a forest's canopy—the upper level of leaves and branches in the treetops—beetles, caterpillars, and other leaf-eating insects abound, providing food for birds such as warblers and tanagers, while arboreal mammals from squirrels to sloths to monkeys consume fruit and leaves.

captive breeding

-In the effort to save species at risk, zoos and botanical gardens have become centers for captive breeding, in which individuals are bred and raised in controlled conditions with the intent of reintroducing their progeny into the wild. -Reintroducing species into areas they used to inhabit is expensive and resource-intensive, but it can pay big dividends.

shelterwood approach

-In the shelterwood approach, small numbers of mature trees are left in place to provide shelter for seedlings as they grow. -even-aged trees

cloning

-In this technique, DNA from an endangered species is inserted into a cultured egg without a nucleus, and the egg is implanted into a female of a closely related species that acts as a surrogate mother. -Several mammals have been cloned in this way, with mixed results. -Some scientists even talk of re-creating extinct species from DNA recovered from preserved body parts.

HIPPCO - invasive species

-Invasive species cause billions of dollars in economic damage each year, and can sometimes push native species toward extinction. -Some introductions are accidental. Examples include animals that escape from the pet trade -Other introductions are intentional. In Lake Victoria, west of the Serengeti, the Nile perch was introduced as a food fish to supply people much-needed protein. -Species native to islands are especially vulnerable to introduced species. Island species have existed in isolation for millennia with relatively few parasites, predators, and competitors -Some of the most devastating invasive species are microscopic pathogens that cause disease.

second growth and secondary forests

-Nearly all the large oaks and maples found in eastern North America today, and even most redwoods of the California coast, are second-growth trees: trees that have sprouted and grown to partial maturity after old-growth trees were cut. -Second-growth trees characterize secondary forest, which contains smaller trees than does primary forest. -The species composition, structure, and nutrient balance of a secondary forest may differ markedly from the primary forest that it replaced.

CITES

-On the global stage, the United Nations has facilitated international treaties to protect biodiversity. -The 1973 Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) protects rare species by banning the international transport of their body parts. -The 1990 global ban on the ivory trade may be this treaty's biggest accomplishment so far. -When nations enforce it, CITES can protect rhinos, elephants, tigers, and other species whose body parts are traded internationally.

ten-ten-ten rule (invasive species)

-One out of every 10 imported organisms will begin to appear in the wild -One out of those 10 will establish in the ecosystem -One of out of 10 established non-native species will become invasive

sustainable forestry certification

-Organizations such as the Forest Stewardship Council (FSC) examine practices and rate them against criteria for sustainability. -They grant sustainable forest certification to forests, companies, and products produced using methods they judge to be sustainable. -Several certification organizations exist, but the FSC is considered to have the strictest standards. -Pursuing sustainable forestry practices is often more costly for producers, but producers recoup these costs when consumers pay more for certified products. -And in the long term, sustainable practices conserve the resource base, thus holding down costs for everyone.

forestry

-Our demand for forest resources and amenities is rising, so we need to take care in managing forests. -Foresters are professionals who manage forests through the practice of forestry. -Foresters must balance our society's demand for forest products against the central importance of forests as ecosystems. -Today, sustainable forest management practices are spreading as informed consumers demand sustainably produced products. -In this way, consumer choice is influencing the ways forests are managed.

bioprospecting

-People have made medicines from plants and animals for centuries, and about half of today's pharmaceuticals are derived from chemical compounds from wild plants. -The world's biodiversity holds a still-greater treasure chest of medicines yet to be discovered. -For this reason, people working for pharmaceutical companies engage in bioprospecting, searching for organisms that might provide new drugs, medicines, foods, or other valuable products. -A recent international survey highlighted animals that show particular promise yet may be lost to extinction before we can profit from what they have to offer.

HIPPCO - pollution

-Pollution can harm organisms in many ways. -Air pollution degrades forest ecosystems and affects the atmosphere and climate. -Water pollution impairs fish and amphibians. -Agricultural runoff containing fertilizers, pesticides, and sediments harms many terrestrial and aquatic species. -Plastic garbage in the ocean can strangle, drown, or choke marine creatures. -However, although pollution can cause extensive damage to wildlife and ecosystems, it tends to be less significant as a cause of population-wide decline than public perception holds it to be, and it is far less influential than habitat loss.

ecological restoration

-Protecting natural areas before they become degraded is the best way to safeguard biodiversity and ecological systems. -However, in some cases we can restore degraded natural systems to a semblance of their former condition through the practice of ecological restoration. -Ecological restoration aims not simply to bring back populations of animals and plants but to reestablish the processes—the cycling of matter and the flow of energy—that make an ecosystem function. -By restoring complex natural systems, restoration ecologists aim to re-create functioning systems that filter pollutants, cleanse water and air, build soil, and recharge groundwater, providing habitat for native wildlife and services for people.

conservation concession

-Some conservation proponents are pursuing community-based conservation projects that empower local people to act as stewards of their forest resources. -In other cases, conservation organizations are buying concessions and using them to preserve forest rather than to cut it down. -In such a conservation concession, the nation receives money and keeps its natural resources intact.

extirpation

-The disappearance of a particular population from a given area, but not the entire species globally, is referred to as "local extinction" or extirpation. -Extirpation is an erosive process that can, over time, lead to extinction.

climate change and pest outbreaks: reasons (forests)

-The first reason is that past forest management has resulted in even-aged forests across large regions, and many trees in these forests are now at a prime age for beetle infestation. -Most at risk are plantation forests dominated by single species that the beetles prefer. -The second reason is climate change. -Milder winters allow beetles to overwinter farther north, and warmer summers speed up their feeding and reproduction. -In Alaska, beetles have switched from a two-year life cycle to a one-year cycle. -In parts of the Rocky Mountains, they now produce two broods per year instead of one. -Meanwhile, droughts like those that have plagued the western and southern United States in recent years have stressed and weakened trees, making them vulnerable to attack.

salvage logging

-The removal of dead trees, or snags, following a natural disturbance (such as fire, windstorm, insect damage, or disease) is called salvage logging. -From a short-term economic standpoint, salvage logging may seem to make good sense. -However, ecologically, snags have immense value; the insects that decay them provide food for wildlife, and many animals depend on holes in snags for nesting and roosting. -Removing timber from recently burned land can also cause soil erosion, impede forest regeneration, and promote additional wildfire.

conservation biology

-The urge to act as responsible stewards of natural systems, and to use science as a tool in this endeavor, sparked the rise of conservation biology. -This scientific discipline is devoted to understanding the factors, forces, and processes that influence the loss, protection, and restoration of biological diversity. -It arose as biologists became increasingly alarmed at the degradation of the natural systems they had spent their lives studying. -choose questions and pursue research with the aim of developing solutions

forensic science

-To counter poaching and other illegal harvesting, scientists have a new tool at their disposal. -Forensic science, or forensics, involves the scientific analysis of evidence to make an identification or answer a question relating to a crime or an accident. -Conservation biologists are now using forensics to protect species at risk. -By analyzing DNA from organisms or their tissues sold at market, researchers can often determine the species or subspecies of organism—and sometimes its geographic origin. -This information can help detect illegal activity and enhance law enforcement.

biodiversity hotspots (protecting ecosystems and biodiversity)

-To prioritize regions for conservation efforts, scientists have mapped biodiversity hotspots. -A biodiversity hotspot is a region that supports an especially great number of species that are endemic, found nowhere else in the world. -To qualify as a hotspot, a region must harbor at least 1500 endemic plant species (0.5% of the world's total plant species). -In addition, a hotspot must have already lost 70% of its habitat to human impact and be at risk of losing more.

prescribed fire

-To reduce fuel loads, protect property, and improve the condition of forests, land management agencies now burn areas of forest intentionally with low-intensity fires under carefully controlled conditions. -Such prescribed fire clears away fuel loads, nourishes the soil with ash, and encourages the vigorous growth of new vegetation. -Because prescribed burning (also called controlled burning) is time intensive and sometimes misunderstood by politicians and the public, prescribed fires are conducted on only a small proportion of land (just more than 2 million acres per year). -As a result, vast areas of American forests remain vulnerable to catastrophic fires.

HIPPCO - overharvesting

-We have always hunted and harvested animals and plants from nature, but our growth in population and consumption is now leading us to remove many species at faster rates than they are able to reproduce. -In the oceans, many fish stocks are now overharvested. -deforestation -Animals that are large in size, are long-lived, and raise few young in their lifetimes (K-selected species) are most vulnerable to hunting. -poaching

extinction

-When a population has declined to a very low level, extinction becomes a possibility. -Extinction occurs when the last member of a species dies and the entire species ceases to exist.

how to timber harvesting methods affect the environment?

-disturb soil, alter habitat, and affect plants and animals. -All methods modify forest structure and composition. -Most methods speed runoff, raise flooding risk, and increase soil erosion, thereby degrading water quality. -When steep hillsides are clear-cut, landslides can result. -Finding ways to minimize these impacts is important, because timber harvesting is necessary to obtain the wood products that all of us use.

valuable resources from forests

-plants for medicines, dyes, and fibers; animals, plants, and fungi for food; and, of course, wood from trees. -For millennia, wood has fueled the fires to cook our food and keep us warm. It has built the homes that keep us sheltered. -It built the ships that carried people and cultures between continents. -And it gave us paper, the medium of the first information revolution. -industrial harvesting has allowed us to extract more timber than ever before, supplying all these needs of a rapidly growing human population and its expanding economy.

selection systems

-selection systems allow uneven-aged stand management, because only some trees are cut at any one time. -In single-tree selection, widely spaced trees are cut one at a time, whereas in group selection, small patches of trees are cut. -The stand's overall rotation time may be the same as in an even-aged approach, because multiple harvests are made, but the stand remains mostly intact between harvests. -Selection systems can maintain much of a forest's structural diversity, but they still have ecological impacts, because moving trucks and machinery over a network of roads and trails to access individual trees compacts the soil and disturbs the forest floor. -Timber companies often resist selection methods because they are expensive, and selection methods are unpopular with loggers because they pose more safety risks than clear-cutting.

clear-cutting

-the simplest method, clear-cutting, all trees in an area are cut at once. -Clear-cutting is cost-efficient, and to some extent it can mimic natural disturbance events such as fires, tornadoes, or windstorms. -However, the ecological impacts of clear-cutting are considerable. An entire ecological community is removed, soil erodes away, and sunlight penetrates to ground level, changing microclimatic conditions. -As a result, new types of plants replace those of the original forest. -Clear-cutting essentially sets in motion a process of succession in which the resulting climax community may be quite different from the original climax community. -even aged trees

subcanopy

Animals also live and feed in the subcanopy (the middle portion of a forest beneath the tree crowns of the canopy)

primary forest

By the 20th century, very little primary forest—natural forest uncut by people—remained in the lower 48 U.S. states, and today even less is left.

understory

animals also live and feed in shrubs and small trees of the understory (the shaded lower level of a forest), and among groundcover plants on the forest floor.