Chapter 13: Forests, Parks an Landscapes

Modern Conflicts over Forestland and Forest ResourcesIn recent decades forest conservation has become an international causeNA Pacific NorthwestTropical rain forestForestry has a long historySilviculture- professional growing of treesWhat should forest be used for?Resources vs. conservation

Modern Conflicts over Forestland and Forest ResourcesForest and civilization closely linkedWood major building material and source of fuelSpiritual and aesthetic value

Modern Conflicts over Forestland and Forest ResourcesPublic service functionsIndirect benefits that people and the environment receive from forestsImproving watershedsWildlife habitatRecreationClimate

The Life of a TreeHow a tree growsLeaves of a tree take up CO2 and absorb sunlightWater transported up from rootsLeaves carry out photosynthesisProducts = simple sugar and oxygenRoots have symbiotic fungi that help extract minerals from the soil

How a Tree GrowsLeaves and roots connected by two transport systemsPhloem- on the inside of the living side of bark, transports sugars and other organic compounds down to stems and rootsXylem- farther inside, transports water and inorganic molecules upward to the leavesSun-powered pump

Tree NichesEach species of tree has its own niche and adapted to specific environmental conditionsE.g., water content of the soilTolerance of shadeSome adapted to early succession, others to later stages

A Foresters View of a ForestTraditionally managed in standsStand- an informal term foresters use to refer to a group of treesUsually the same specie and successional ageEven- aged standsUneven-aged standsForest that has never been cute is virgin forestOld growth forestA forest cut and regrown is secondary growth forest

A Foresters View of a ForestRotation time- the time between cuts of a standForesters and forest ecologists group the trees in a forest intoDominantsCodominantsIntermediateSuppressedSite quality- max timber crop the site can produce in a given time

Approaches to Forest ManagementManaging forests can involve removing poorly formed and unproductive trees to permit larger trees to growPlanting genetically controlled seedlingsControlling pests and diseasesFertilizing the soil

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

Alternatives to Clear-CuttingSelective cutting- individual trees are marked and cut (thinning)Strip-cutting- narrow rows of forest are cut, leaving wooded corridors whose trees provide seeds Shelterwood-cutting- practice of cutting dead and less desirable trees first and later cutting mature trees.Seed-tree cutting- removes all but a few seed trees to promote regeneration of the forest

Experimental Test of Clear-CuttingScientist have tested the effects of clear cuttingHubbard Brook experimental forest in NHErosion increased and pattern of water runoff changed substantiallyExposed soil decayed more rapidlyStream water exceeded public health standards for nitrates

Experimental Test of Clear-CuttingHJ Andrews Experimental Forest in ORIncrease in the frequency of landslides after clear cuttingC-c also changes chemical cycling in forests and causes the soil to lose chemical elements necessary for life

Experimental Test of Clear-CuttingExperiments show Clear-cutting can be a poor practice on steep slopes in areas of moderate to heavy rainfallClear-cutting on an appropriate spatial scale may be useful to regenerate desirable speciesWhere ground is level, rainfall moderate, and desirable species require open ground to grow

Plantation ForestryPlantation- a stand of a single species typically planted in straight rowsMuch like agricultureFertilizers added, mechanized harvestingOffer a solution to the pressure on natural forests.High-yield forests could provide all the worlds timber

Sustainable ForestryA sustainable forest is one from which a resource 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.

What is Sustainability and How is it Applied to ForestsTwo basic kinds of ecological sustainabilitySustainability of the harvest of a specific resource w/in an ecosystem (harvest of timber)Sustainability of the entire ecosystem (forest as an ecosystem)Lack scientific data to demonstrate that either type ever achieved in forests

Certification of Forest PracticesCompare the actual practices of a specific corporation or government agencies w/ practices that are believed to be consistent w/ sustainability.Dont know if beliefs are correct or practices really sustainableMovement to call them well-managed forests or improved management

A Global Perspective on ForestsVegetation of any kind can affect the atmosphere in four ways1. By changing the color of the surface and therefore the amount of sunlight reflected and absorbed.2. By increasing the amount of water transpired and evaporated from the surface to the atmosphere.

A Global Perspective on Forests3. By changing the rate at which greenhouse gases are released from Earths surface into the atmosphere.4. By changing surface roughness, which affects wind speed at the surface.

World Forest Area, Global Production and Consumption of Forest ResourcesCountries differ greatly in their forest resourcesPotential of their land and climate for tree growthHistory of land use and deforestation

World Forest Area, Global Production and Consumption of Forest ResourcesDeveloped countries account foe 70% of worlds total production and consumption of industrial wood productsDeveloping countries produce and consume about 90% of wood used as firewood90% of world timber tradeConstruction, pulp and paperNA is the dominant supplier

World Forest Area, Global Production and Consumption of Forest ResourcesIn recent years world trade in timber has not grown substantially.The fundamental questions areWhether forests can continue to produce at least this amount of timber for an infinite periodWhether they can produce even more as the population grows

Deforestation: A Global DilemmaDeforestation is estimated to have increased erosion and caused the loss of 562 million hectares of soil.Deforestation in one country can affects countries downstreamE.g. Nepal and India

Deforestation: A Global DilemmaIs forested area increasing or decreasing?Information is lacking on which to base an accurate evaluationForest cover is large, often remoteDifficult to assess the total amount of forest areaEstimates suggest an annual loss each year of 7.3 million hectares

History of DeforestationHas occurred in all societies fromEarly Greece and Roman Empire Prehistoric farmers in DenmarkMedieval Great BritainUpon colonization of the New WorldThe greatest losses in the present century taken place in South America

Causes of DeforestationTwo most common reasonsClear land for agriculture and settlement To use to sell timber for lumber, paper products, or fuel

The World Firewood ShortageIn many parts of the world, wood is a major energy source.As the human population grows, use of firewood increases.Management is essential

Indirect DeforestationThe death of trees from pollution or diseaseAcid rainOzoneOther air pollutantsAll can increase susceptibility to diseaseGlobal climate change may lead toMajor die-off and shift in areas of potential growth

Parks, Nature Preserves, and WildernessLandscapes may be protected in different waysGovernment established parks, nature preserves, and wilderness areasPrivate organizations buying land and maintaining it as nature preserves

Parks and PreservesPark- an area set aside for use by peopleNature preserve- may be use by people but primary purpose the conservation of some resourceBoth create ecological islandsIsland biogeography used in design and management

Parks and Preserves as IslandsThe size of the park and the diversity of habitats determine the # of species that can be maintained.The further the park is from other parks or sources of species, the fewer species are found.

Parks and Preserves as IslandsMost park boundaries have been arbitrarily set.E.g., Lake Manyara National Park in TanzaniaOriginal boundaries did not include elephants entire yearly rangeElephants and farmer came into direct conflictBoundary shifted

Brief History of ParksThe French work parc once referred to an enclosed area for keeping wildlife to be hunted.E.g., Coto Donana National Park on the coast of SpainOnce country home of noblesNow a stop over for 80% of birds migrating between Europe and Africa

Brief History of ParksFirst public park Victoria Park in Great Britain, 1842Concept of national park originated in NA in the 19th centuryYosemite designated in 1864Preserve unique awesome landscapes20th century emphasis more ecological

Conflicts in Managing ParksMajor conflicts generally have to do withSizeWhat kinds and levels of access and activities will be available

How Much Land Should be in ParksWhat percentage of the landscape should be in parks or nature preserves?If parks are to function as biological preserves, they must be adequate in size and habitat diversity.

Conserving WildernessAs a modern legal concept, wilderness is an area undisturbed by people.New idea introduced in the second half of the 20th centuryUS Wilderness Act of 1964First time wilderness recognized by national lawland retaining its primeval character and influence

Conserving WildernessWilderness1. Imprint of human work is unnoticeable2. There are opportunities for solitude and primitive and unconfined recreation3. There are at least 5,000 acresWilderness vs Wildness

Conflicts in Managing WildernessLegal definition given rise to several controversiesDesire to include more land as wildernessDesire to develop this land and its natural resourcesCan view goal of managing 1. To preserve nature undisturbed by people2. To provide people w/ a wilderness experience