Chapter 18 Land Resources

Transcription

1 Chapter 18 Land Resurces

2 Land Use Overview f Chapter 18 Wrld land use US land use Wilderness Park and Wildlife Refuges Natinal Parks Wildlife Refuge Frests Frest management Defrestatin Rangeland and Agricultural Land Wetlands and Castal Areas Cnservatin f Land Resurces

3 Land Use- Wrldwide

4 Land Use- United States

5 Land Use- United States 55% f US land is privately wned 3% by Native peples Remainder f land is wned by gvernment Mst federally wned land is in Alaska and 11 western states

6 Land Use- United States Vast majrity is resurce extractin.

7 Managing Public and Private Land Public Planning and Land Use Land use decisins are cmplex and have multiple effects Must take int accunt all repercussins f prpsed land use Management f Federal Land Wide-Use Mvement Envirnmental Mvement

8 Managing Public and Private Land- Think-Pair-Share Hw are farms rutinely frced ut f urban areas? Is increasing the tax base a justifiable reasn t encurage urban develpment? Why and why nt?

9 Managing Public and Private Land- Think-Pair-Share Hw are farms rutinely frced ut f urban areas? Rising prperty values make taxes t high fr the farm t supprt. Is increasing the tax base a justifiable reasn t encurage urban develpment? Why and why nt? This ften desn t imprve the situatin fr individuals, as mst f the revenue pays fr services in the develped area.

10 Management f Federal Lands- tw views Wise-use mvement Seek private enterprise access t resurces n federal lands Envirnmental mvement Seek the preservatin f resurces n federal lands.

11 Management f Federal Lands- tw views Wise-use mvement Seek private enterprise access t resurces n federal lands. Believe the purpse f federal lands is t enhance ecnmic grwth. Envirnmental mvement Seek the preservatin f resurces n federal lands. View federal lands as a legacy f /fr US citizens.

12 Management f Federal Lands- tw views Wise Use Mvement Timber manage all Natinal Frest (incl. Old Grwth) Mining and cmmercial develpment (where apprpriate) Unrestricted develpment f wetlands (drain the swamps) Sell resurces t private interests fr sustainable resurce extractin. What are the merits f each view? On balance which view has mre merit in lng-term?

13 Wilderness Parks and Wildlife Refuges Wilderness A prtected area f land in which n human develpment is permitted Wilderness Act (1964) Set aside federally wned land (that retains its primeval character) as part f Natinal Wilderness Preservatin System (n Natinal Parks, Frests, and Wildlife Refuges) N develpment permitted (including rads) Managed by NPS, USFS, FWS & BLM Over half are in Alaska and mst f remainder in the west f lwer 48 states.

14 Wilderness Sme areas have a limited number f permitted human guests t reduce impact Other prblems include invasive species

15 Natinal Park System Created in 1916 Currently includes 58 parks Primary gal Teach peple abut the natural envirnment, management f natural resurces and histry f a site Ysemite Natinal Park

16 Natinal Park System Threats t U.S. Parks Crime & Vandalism Traffic jams Pllutin f the sil, water and air Originating bth inside and utside the park Resurce vilatins Why s many impacts? Entrance fees =5% f Park expenses!

17 Natinal Park System Natural Regulatin: A park management plicy that invlves letting nature take its curse mst f the time, with crrective actins taken as needed t adjust fr changes caused by pervasive human activities. N culling wildlife N suppressing wildfire

18 Wildlife Refuges Natinal Wildlife Refuge System (Teddy Rsevelt-1903) Represent all majr ecsystems funds in the US Missin T preserve lands and waters fr the cnservatin f fishes, wildlife and plants f the US Recreatin (including hunting and fishing) are permitted Cannt impede cnservatin effrts

19 Frests-tpics Rle in Hydrlgic Cycle (right) Withut frest, mst water runs-ff. Frest Management Defrestatin Frest Trends in the US Trends in Trpical Frests Breal Frests

20 Frest Management Traditinal Frest Management Lw diversity- mncultures Mncutlure: Eclgical simplificatin in which nly ne type f plant is cultivated ver a large area(right) Managed fr timber prductin

21 Frest Management Eclgical Sustainable Frest Management Envirnmentally balanced Diverse trees Prevent sil ersin Preserve watersheds Wildlife crridrs- unlgged Sustainable Frestry: Prvide fr current frest needs withut depriving future generatins frm meeting their frest needs.

22 Frest Management Think-Pair-Share Eclgical Sustainable Frest Management What are the strengths and weaknesses fr each f the harvesting methds n the next slide (shwn n page 410). Cnsider ersin, seed germinatin and seedling grwth, species richness, and harvesting cst.

23 Harvesting Trees -Cnsider ersin, seed germinatin and seedling grwth, species richness, and harvesting cst.

24 Harvesting Trees - Clearcutting Clearcutting: A lgging practice in which all the trees in a stand are cut, leaving the stumps.

25 Defrestatin Temprary r permanent clearance f large expanses f frest fr agriculture r ther use Wrld frests shrank 90 millin acres frm Causes Fire Expansin f agriculture Cnstructin f rads Tree harvest Insect and disease

26 Defrestatin The temprary r permanent clearance f frest fr agriculture r ther uses. Results Decreased sil fertility Uncntrlled sil ersin Prductin f hydrelectric pwer (silt build up behind dams) Increased sedimentatin f waterways Frmatin f deserts Extinctin f species Glbal climate changes Habitat fragmentatin

27 Frest Trends in US Mst temperate frests are steady r expanding Returning stands lack bidiversity f riginal frests.

28 Frest Trends in US Mre than half f US frest are privately wned (right) Frest Legacy Prgram: 1990 Farm Bill; helps private landwners prtect envirnmentally imprtant frests. Cnservatin easement: A legal agreement that prtects privately wned frest r ther prperty frm develpment fr a specified number f years.

29 US Natinal Frests Managed fr multiple uses Rad building is an issue Timber harvest Livestck frage Water resurce and watershed prtectin Mining, hunting, fishing, etc. Prvides lgging cmpanies with access t frest Clearcutting is an issue

30 Case-In-Pint Tngass Natinal Park One f wrld s few temperate rainfrests Prime lgging area Mdified 1997 Frest Plan Radless Area Cnservatin Rule (2000) Plitics rules gvernment agencies

31 Case-In-Pint Tngass Natinal Park Think Pair - Share Read the Case in Pint abut the Tngas Natinal Frest, p D yu think Alaska and the Natin are using the resurce respnsibly (sustainably)?

32 Trends in Trpical Frests Trpical rainfrests (belw) and trpical dry frests

33 Disappearing Trpical Rain Frests Ppulatin grwth Immediate causes Strng crrelatin, but can t accunt fr all f it. Subsistence agriculture (50%) Cmmercial lgging (20%) Cattle ranching (10%) Other causes Mining Hydrelectric pwer

34 Disappearing Trpical Dry Frests Primarily destryed fr fuelwd Used fr heating and cking Much is cnverted t charcal, wasting 50% f the wd s energy!

35 Breal Frests Wrld s largest bime Extensive clearcutting Primary surce f wrld s industrial wd and wd fiber Annual harvest estimated at an area twice as large as the Brazilian Amazn rain frest! Canada and Russia harvests are likely unstainable.

36 Rangeland and Agricultural lands Rangeland Land that is nt intensively managed and is used fr grazing livestck

37 Rangeland Degradatin and Defrestatin Overgrazing leaves grund barren Land degradatin Animals exceed their carrying capacity Natural r human-induced prcess that decreases future ability f land t supprt crps r livestck Desertificatin/degradatin: are synnyms Degradatin f nce fertile land int nnprductive desert Caused by vergrazing cmbined with extended drught cnditins.

38 Rangeland Trends in US Make up 30% f ttal US land area Pressure frm develpers t subdivide 2/3 privately wned Cnservatin grups purchasing cnservatin easements. Public rangeland managed by: Taylr Grazing Act (1934) Federal Land Plicy and Management Act (1976)

39 Rangeland Trends in US Grazing fees are an issue. I ll say! BLM charges $1.xx per cw per mnth. Private wners charge mre than $13. Yu can t bid n a grazing permit, nly lcal ranchers can! In 2003, taxpayers paid $67 millin dllars mre n public rangelands than they cllected in grazing fees!!!!

40 Agricultural Land US has 300 millin acres f prime farmland Much is being vertaken by suburban sprawl Parking lts Husing develpments Shpping malls

41 Agricultural Land 1996 Farm Bill included funding fr establishing a natinal FARMLAND PROTECTION PROGRAM. Farmers sell cnservatin easements that prevent cnversin f farmland t nn-agricultural uses.

42 Wetlands Lands that are usually cvered with water fr at least part f the year Have characteristic sils and watertlerant vegetatin Benefits Habitat fr migratry waterfwl and wildlife (including huge percentages f endangered r threatened species) Recharge grundwater Reduce damage frm flding Imprve water quality Prduce many cmmercially imprtant prducts

43 Wetlands Human activity that threatens wetlands Drainage fr agriculture r msquit cntrl Dredging fr navigatin Cnstructin f dams, dykes r seawalls Filling in fr slid waste dispsal Rad building Mining fr gravel, fssil fuels, etc. Shrinking 58,500 acres per year Over half f the wetlands in the lwer 48 during Clnial times have disappeared. Clean Water act prtects castal wetlands well, but nt inland wetlands (where mst wetlands are lcated).

44 Restring Wetlands N Net Lss f Wetlands: Develpment f wetlands is allwed if crrespnding amunt f previusly cnverted wetland is restred Nt all wetland restratins are successful

45 Castlines Castal wetlands Prvide fd and habitat fr many aquatic animals Histrically regarded as wasteland US starting t see imprtance f prtecting this envirnment Retaining seawalls (right)

46 Castal Demgraphics Many castal areas verdevelped 3.8 billin peple live within 150km f castline 6.4 billin peple will likely live there by 2025 United States 14 f 20 largest US cities alng cast 19 f 20 mst densely ppulated cuntries alng casts

47 Cnservatin and Land Resurces All types f ecsystems must be preserved Fur criteria f imprtance: Areas lst r degraded since Eurpean clnizatin Number f present examples f a particular ecsystem (r the ttal area) Estimate f the likelihd that a given ecsystem will lst a significant area r be degraded in next 10 years Number f threatened and endangered species living in the ecsystem

48 Cnservatin and Land Resurces