• Vocabulary:– Old-Growth Forest: a forest that has never been cut– Second-Growth Forest: has been cut and re-grown– Rotation Time: the time between cuts

• Foresters group trees into:– Dominants: tallest, most common, most vigorous– Codominants: fairly common, sharing the canomy of the forest– Intermediate: forming a layer of growth below the dominants– Suppressed: growing in the understory

• Sites are classified by site quality: the maximum timber crop the site can produce in a given time

A Forester’s View of a Forest

4 types:1. Shelterwood-Cutting:

• Cutting dead and less desirable tress first and then cutting the mature trees later. Young trees always left in the forest.

2. Seed-Tree Cutting: • Removes all but a few seed trees (mature trees with high seed

production and good genetics)3. Selective Cutting

• Individual trees are marked and cut • Example: Thinning is when poorly formed trees are

removed• Example: Sometimes specific size trees are removed etc.

4. Strip-Cutting:1. Narrow rows of forests are cut leaving wooded corridors.

Clear-CuttingThe cutting of all trees in a stand at the same time.

Effects of Clear Cutting onForest Chemical Cycling

Effects of Clear Cutting onForest Chemical Cycling

Effects of Clear Cutting onForest Chemical Cycling

Nitrate concentration in streams following logging and burning of slash (leaves brances and other tree debris = slash)

Forests, Parks and Landscapes, Wildlife, Fisheries and Endangered Species

Plantation Forestry• Plantation: a stand of single species

planted in straight rows

• Properly managed plantations can relieve pressure on forests

Sustainable Forest• Sustainable forests occur when a forest is managed so that

a resource in it can be harvested at a rate that does not decrease the ability of the forest ecosystem to continue to provide that same rate of harvest indefinitely. Two types– Sustainablity of the harvest of a SPECIFIC resource (timber)– Sustainability of the entire ecosystem (entire forest ecosystem)

• Three are few examples of sustainablity. • The “certification of sustainable forestry” developed

where organizations certify forest practices– This involves:

• Determining which methods appear most consistent with sustainability• Comparing the management of a specific forest with those standards

– PROBLEM: A series of harvests is necessary to prove sustainability and the proof therefore lies in the future.

Global Perspectives on Forests

• Changing color of the surface and the amount of sunlight reflected and absorbed

• Increasing the amount of water transpired and evaporated from the surface to the atmosphere

• Changing the rate at which greenhouse gases are released from the Earth’s surface into the atmosphere

• Changing the “surface roughness,” which affects wind speed at the surface

4 Ways Vegetation Can Effect the Atmosphere thereby influencing the entire biosphere

Deforestation• History

– Forests have been being cut down since times of the Roman Empire onward

– The greatest losses in the present century have occurred in South America 4.3 million acres a year are being lost since the year 2000!

– Human population growth is the largest cause• Causes

As populations grow we cut for two main reasons1. Clear land for agriculture & housing2. For goods, such as lumber, paper, fuel etc.

• World Firewood Shortage– 63% of all wood produced is used for firewood

• Indirect Deforestation– Killing of forests due to pollution or disease.

Countries with the Largest Forested Areas

Note 1 hectare = 10,000 square meters or 2.471 acres

The World’s Forested Area

Forest and Rangeland in the Contiguous United States

Estimated volume of harvested

timber.

Sawtimber volume

Land use by area

In the late 20th century 3/4ths of the commercial forests (in the lower 48) were in the eastern US with 70% of the swtimer volume in the west. Today however, sawtimber volume is shifting eastward because of plantation forestry in the southeast.

Parks, Nature and Wilderness

• Why do we want to have parks? What are their goals? See page 253 for details.

• Wilderness: an area undisturbed by people

• Managing parks for biological conservation is a relatively new idea. Parks that are too small or in the wrong shape may not be able to sustain their species

A Point of Confusion

Edge Effect:

• When forests are being cut or a park is first established some animals may take refuge towards the edges.

• This is different than the edge effect we discussed during habitat fragmentation.

A History of Parks• 1842 – The first major public park of the

modern area was Victoria Park in Great Britain.

• 1864 – Yosemite was the first designated national park in the world.

• 1872 – Yellowstone was established and was the first park to be called a “National Park”

Please read about a history of parks on page 255 you need to know this!

•A national park not only provides public access but it affords protection of nature. In the 20th century conservation became the focus of national parks worldwide.•Additionally keep in mind that a goal of park and nature preserve management is maintaining biodiversity in national parks for recreation such as hunting.

So you want to save a species? --Chapter 14--

What does that really mean?1. A wild creature in its wild habitat as a

symbol of its wilderness?

2. A wild creature in a managed habitat, so the species can feed and reproduce with little interference so we can see it in a naturalistic habitat?

3. A population in a zoo, so the genetic characteristics are maintained in live individuals?

4. Genetic material only – frozen cells containing DNA from a species for future scientific research?

Traditional Single-Species Wildlife Management

• Maximum Sustainable Yield (MSY): The population size that yielded maximum production

Assumptions1. The population could be represented by a single number (its total size)

FALSE!2. The environment is constant (except where humans have created

change) FALSE!3. Undisturbed by humans a population would grow to its fixed carrying

capacity FALSE!• Minimal Viable Population: The goal for a threatened or endangered

species. Defined as the estimated smallest population that can maintain itself and its genetic variability indefinitely.

• Optimum Sustainable Population: The population level that results in an optimum sustainable yield. The level is in some way best for the population, its ecological community, its ecosystem or the biosphere

The Logistic Growth CurvePlease read the caption of this image on page 266 figure 14.4 and summarize in your notes what this graph is trying to say in your own words. Non-volunteers will be randomly selected to answer.

Classic Cases of Wildlife Management

• The American Grisly (Grizzly) Bear– Endangered due to hunting & habitat destruction– Restore to what level? How do we know?

• The American Bison– Hunter for their hides– Killed in war against native Americans– Recovering due in part to ranchers raising them for profit

• A common goal in wildlife conservation is to “restore” the abundance of a species

• Adequate information of the abundance of a species is very rare

Improved Approaches to Wildlife Management

• Time Series and Historical Range of Variation- Time Series: an estimate of a population over a number of years- Historical Range of Variation: the known range of abundances of a population over some past time interval

• Age Structure as Useful Information• Harvests as an Estimate of Numbers

– Catch per Unit Effort: estimates previous animal abundance. Assumes same effort by hunters.

Whooping Cranes

• Endangered due to– Destruction of wetlands– Habitat loss due to urbinization– Agricultural modification of their flyways– All of these things casued the following:

• Food web disruption• Loss of breeding grounds• Loss of nesting sites• Loss of migration habitat

– Hunted for a variety of reasons• For goods: feathers, meat, skins, eggs, trophies etc.• For sport

– Sometimes killed by accident

Whooping Crane Migration route and Change on Population from 1940 - 2000

Fish & Fishing• Fish provides 16% of the world’s protein

– In North America only 6.6% comes from fish– 28% in the Far East– 22% in Central Asia– 21% in Africa

• Fish are especially important in developing countries.• Fishing is an international trade, but the following countries

dominate:– Japan, China, Russia, Chile and the US

• The amount of fish harvest from the oceans has increase dramatically. It has more than doubled between 1960 and 1980 where it rose from 35 million MT (metric tons) to 72 million MT.

• There are an estimated 27,000 species of fish and shellfish in the ocean.

More about Fishing• Most fish come from capture fisheries

– That is they are caught in the wild

• Some fishing methods1. Driftners: nets that are dragged through the water and

catch everything in their path including mammals, non-target fish, birds etc. These non-target organisms are called “by-catch” or “by the catch”.

2. Long lining: Using long lines that have bated hooks to catch fish. Also results in “by-catch” catches.

3. Bottom trawling: Heavy nets are scraped along the surface of the ocean. This is also indiscriminant and not only catches everything in its path but it destroys everything in their path.

Fisheries• The Decline of Fish Populations

• Which of these fish are caught for food and which are caught as “by the catch”?

• Can Commercial Fishing Ever Be Sustainable?– Past experience suggests that economically

beneficial sustainability is unlikely for most wild populations

Roundnose Grenadier Blue Hake Onion-Eye Grenadier

The World’s Major Fisheries

Orange areas are major fisheries. The darker the area the greater the harvest and the more important the fishery.

Whaling – A History• Early whale hunters killed whales from the shore or

from boats near the shore• 11th-12th century boards allowed hunting of whales

from bays and off the coast and then brought them to shore for processing

• In the 19th century whaling became “pelagic” that is people hunt AND process whales from the open ocean. This was a product of the industrial revolution.

• 20th century allowed even more whales to be killed than in the 19th century resulting in a worldwide decline of most species of whale.

• Attempts to control whaling began in 1924 at the Convention for the Regulation of Whaling.

• In 1931 the Convention for the Regulation of Whaling was signed by 21 countries. This was the first agreement on whaling.

• In 1946 the IWC (International Whaling Commission) was established at a conference in Washing DC.

• In 1982 the IWC put an end to commercial whaling.• In 2006 a movement in the IWC has been put forth to

control whaling rather than end it. •Japan, Norway and Iceland are pro-whaling•Australia, the UK, New Zealand and the US are anti- whaling

Tuna Catch Decline

Fish Catch in the Chesapeake Bay

A Solution?

• Aquaculture: raising of fish and other aquatic species in captivity. This is already being done for some species such as shrimp and salmon where the economic benefits are high.

• PROBLEM: Accidental release of farmed fish. This can cause disease and a host of other problems. Also since many of the fish raised in captivity are carnivorous… many are being fed captured fish!