154 lines
5.7 KiB
Plaintext
154 lines
5.7 KiB
Plaintext
edge erienslve saileled shrub—lorlr arsoeianons «orb.
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are any nun~gmss or herbareous planisl, dunes on
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harder paverrlen. areas, and aims. bare pauemene bi
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harder roars win. iareied pebble. (aim plaln or leg).
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where aver-grazing has no. been .he deminan.
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iearure ol larui use. a desen may presen. an eyeelewl
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appearanee oi a Iow-(Xowned lorese wi.h shrub
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nadersmmy, and some areas may bear rirr. or neher rn
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puni species lhan a mane humid idles. fllwmnmnl ln
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dmxl, nowever, mere will usually be larger or smaller
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areas oi bale soil beiween all mijnr plan. dumps or
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species, Closer .nspeeuon may reyeal a
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WHIgAI-Ilthrn teryplryami erusl on live bale areas,
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more or less .nlar. dependlng an lne lreduenry o!
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hooded anirrlala nus Wm": crusl ls a erirleal and
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delieaie lealure prevenllne wlnd eruslpn. irs
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preservanun ls essenlial larsoil surlnllry.
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some learules dl .he deserve nlv
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- l'lanis produee (uplons seed wilh long vinbilny,
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seed .s olien wind-dispersed.
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. Termlles and arm are male eased-ye inan worms as
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soil ae.alo.s and deeamposels
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- ham may iall in mrasale pauerns, so .na. vthnll
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B also a varied rrlasaie oi hrs and raln. and ephemeral
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planls al dlliereni response stages lrun. growih In
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deeay are evideni New generaiions a. snrubs may
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erperseme laveurable leedlln; rondllions as rarely as
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every 7e2il years This .hen peeonles .lle perlud oi
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reeruiunenlel new iomsis or shmblands.
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. Mueh a: .he waier runaril syslem may end nm in
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rivers lull in rnland salkpin: or baslns irniarllrlr
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dralnagel, llom whien all wa.erevenn.ally evapdraies.
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- Normal erosion is by , bu. rare rloudbursls
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shape .he mam erosion ieaiures and move ras.
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dummies el loose maienai ironi .he hllls .n .urbulerll
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mean. new wlnd imnspons malerials ideally in due:
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riarns.
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- Animals burrow, seek shade, or are ruserurrlal in
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mder id eunserve Wain; many are highly adapied (or
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waler eunservanon.
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. rlanl assdelauons may be very varied irl response
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in (hinges ln longemrrn aspen; sneh as slope, srnl
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deprh, sallnl.y, browslne lnierlsiry, pH, and nxk .ype
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smleml) areas have sieppe. scrub, arld law ioresl
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veseeanan, ARID .s sleppe and saaiiered low shrubs,
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and lrue DESERT has llllle hu| oases and ephemeral
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quaflun appearing alier .he rare rams Desens have a
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ramrall elasslhrarlbn ol-
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. Hypemnd: in em annual average (cg Alaeama.
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Nanub am, eenrral Samuel.
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- hmmly dry. —5 an annual average.
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. And. 545 err. annual average ie 5. Mohave.
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50mm, Sahara marpmsi.
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. 5emleari sad rm, maximum ul en. lmueh eiihr
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AulInJIan .ieseris. Asian deseris, Kalallaril.
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Above in em, and lo 75 or mu en. rainlall we have
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lpoierulallyi dry savarmah ioresis. and ii .s up .a .his
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larier level .ha. we will be dealing wilh ln lhrs ehapier
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Ramllfl .s not dependable .n and areas, wur. a normal
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sin vnrlzhun. and a poierlrlal me var-.siian .n any one
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yflr. rulenilal erraporsiion can nnge lroln values or
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m urn/yearln hyperand areas re. imem rn neppe,
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We ear. also regard lhe polar lee—eaps as hyperand
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llor preeiplualion) bu. evaporaiurn levels are very low?
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wlnd removal ol snow aeplnaes evaporallon, aorh lhe
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vzvy eold and hyperal-ld hai desens nave one Hang in
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mmmon—ihey mummu'y and preserves yul raneeoi
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organic and labrieaied subslanees, whlrh plan": a
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rrlanaeemenl problem when dealing wlih pollufiun, as
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breakdown ell mus. organic subsianees ean be very
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slow in rhe absenee oi waler.
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A parados ln almos. all large deseri ur and areas is
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.he exisienee ul .wo iypes ol mare humld
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envlronmerlis. EXOTIC RIVERS which llow .n iroln
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belierewaieled or kinsud ngions, and 0.455 There
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.s a uurd. invlslble waier .esouree. .hai ul aouxrzxs
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(underground walers) All musl be used wuh gr“!
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cauilan, as waler in all oi lirese resuumes ran be ideally
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eahausled, and auullers ran be depleied over vns.
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alas by immodes. use las ihey have been in are usm
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rhls misuse (all cause widuprud subsidenee, collapse
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ul lhe aauller. and . permanani disappealanre ol lhnse
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oases wrueh were in depressions led byiheaeuuer
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lrlslead oi eoneenbrallng on exorie waier in desaris,
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we should niiernpl be unwise ille lnpul or waler mid ihe
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aqullers. solls. and sneams. and lo rehum.d.ly lhe
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deserl arr by planllng irees and proieellng errsilng
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vegeiallun. ii is me presenee ol irees and shrubs.
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.ransplrlne rsiher lhan eviwmlmg wan-r, rhal keep rhe
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deserl sails irom evaporaling a. sell level, Onee
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evaporailon alone eperales, capillary dnlun aulsklv
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brlnp subruriaee salis lo lhe suriare as maple - m.
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sodium, ealriurn, and palmum edmpoundsiehklrldes,
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sulphales. sarbonalesl and we ran m longer estdbm
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vegeuliveeaver.
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When we talk all and lands. we should also
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remember equalunal low islands, unsiablllsed sand
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dunes in midsummer even in eoal elirrlaies. and whole
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penbds di relanve rims!“ even ln more hunud areas
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iimluding ihe dry wanrels in many sublmplal aw”).
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nu. is why l. .s unprirlani w speeiiy planeel'ms and
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droughlenardy plarus lor many siruarluns, and why
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any smlzgy In ad waler .r..o sell, and keep li lhem. ls
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worlhwhlle There are Inge areas ol Meduerrarrean
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elimale .rn desen borders wmeh a.e ~arid- ll lhey have
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deep sands and poor waler relenilon,
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a pnneund duesllon lo ask abou. desens cancerns
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uur basle usage Lulesiaeir herding has been
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|radillonal~and derasiannl; Ausirallans reruvlans
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and Alricins, Arabs. and rlbelans have all used and
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areas ior herding Abungmal Ausrralians managed
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bener. by harvcsung .he namral abundanee nl deseris
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sa lira. .he armlral siress al herds was nei
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superimposed on lire nalural siresses or dry seasons.
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We smuld Wlhml uur sualegles el desen use, and
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.he way we oeeupy and lands l. is possible in esubllsrl
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a unhmy—devduped eore senlmmh .a sel a... hardy
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planis lor many lsrlamelres along lavourable areas or
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CORRIDORS and no ralre 2dvamage ol (he rare rams Ia
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esblblislr a wlde biologic“ resnulee lor dry yurs l. ls
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309
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