145 lines
4.9 KiB
Plaintext
145 lines
4.9 KiB
Plaintext
as: This plan! rappnse is flxlkzd eolheolher cydk
|
||
laerors char cause hare numbers lo sharply decline on
|
||
oeeiehruwsed range. In hm deserls, lire and knowing,
|
||
oopprcinp and firewood gathering can produce such
|
||
pulmwus nielaholiies a wide rang: ol bath woody
|
||
aaid ephemeral planrs llaryani, l P, ml, Nalrrral
|
||
Binary mill
|
||
|
||
|
||
|
||
11.13
|
||
|
||
DESEKTll-‘ICATION AND THE
|
||
SALTING OF SOILS
|
||
|
||
nsamncmoN
|
||
1e Hut-via, H,N., 1968 in La peserlr/ieoliori du Sal-on.
|
||
llnl. BloI Pm; secr c. T Collngne Harninarriel,
|
||
Kantian) gm lhe following arises ol desemfi—oahnm
|
||
Independemly ol any long-Term or cyelre clirnalrc
|
||
change.
|
||
ovanculec, assisred by well-dnlhng lo
|
||
oiainl 'rr higher shack nunihers. Herds can nor now
|
||
adlusl lo clirnalie laelors, and an be held ai hlgh
|
||
numbers mild well iruo dmughl periods
|
||
|
||
- OVERGRAZXNC: messing lhe vegeralron kyand
|
||
mvuy, espeeially irear wells,
|
||
|
||
- FUEL use; Kmarillg hmbus cu! but um replanred
|
||
(Inn/ans also lakes lhousands ol neesl Frequpnr burns
|
||
|
||
|
||
|
||
in;
|
||
|
||
- sleNc 0F NOMADS local grazing and luel-
|
||
(“lung siress causes a cone or deslrucrion, usually
|
||
uenued ori wells: no regenerallon is possibl: as people
|
||
are no long” noinadrc
|
||
|
||
- CROPPING, ollen as a resuli (u a railing herd
|
||
supporl and iii responae m populanon increase This
|
||
ulsndr down he I5 erri rarruoll, wheres 40 cm is aceep
|
||
red as lhe lower lunrl lordependable cropping,
|
||
|
||
- EXTENSION OF CLEARING, lolluwlng on law
|
||
enrp mums, lhus less hlluw, lhis pally increases soil
|
||
oompacuon and topsoil loss
|
||
|
||
. EXCESSIVE WATER USE ui modern cirrus on|y:
|
||
due m parlieular rodeep wellsor powered pumps. The
|
||
upper uqmllr dries up, and lhe lm| eaeeas waler uk
|
||
lends lo salinanon olsurfim soils
|
||
|
||
- SURFACE DRYING; lhe deserr heeorries irre-
|
||
vocably abandoned when oases dry up due |0
|
||
gmndwaler removal.
|
||
|
||
Damage in hills is devegeialion. erosion, denuda-
|
||
uun. ln eroded soils calcreee and lemerele or allaeie is
|
||
zxyoscd. prevailing produciire use Deep erosion euls
|
||
gulhes in lields, dusl slorrns do luriher damage
|
||
Onceeraole dunes wlll lheri srarr ro move All lheac m
|
||
prerenlable problems il early signs are heeded and il
|
||
we have goodwlll m lhe earrh. Above all, dlsgmllunnn
|
||
a land-use, hence polirical, proolern, and relieve hhc
|
||
poonlies ol govemmznls
|
||
|
||
While l agree wrlh all ol lhe above, lhem ue orher
|
||
laclors anecled by and rclaled eo lhern. and necessary
|
||
in more Fully undersrarid W: process ol desenriicaiion
|
||
|
||
|
||
|
||
These are-
|
||
|
||
- WIND EFFECIS: Bnlh lhe drylng eueel, wind
|
||
erosion, and sand plase on plans.
|
||
|
||
. soil EFFEGS Soil (nHIw due lo delloceulaiiori
|
||
ul :lays; hollows and pans drvelop soil aalnn. due lo
|
||
lhe above and lo we dereloprnenr ol hardpans in lhe a
|
||
soil Ilnrizmi,
|
||
|
||
r mm: EFl-‘EClS: The increase ol overland warer
|
||
flow due lo deloresrauon and ay-isulniral mmpaeelon
|
||
ol soils, Calming gullying and all rransporl m lower
|
||
soils Added In lhis, [hm is a else ln sall waler laoles
|
||
due lo deloresranon
|
||
|
||
- WETLANDSALTING' The orecuse ol oiineral and
|
||
nlkrkh walers on dayvfraellon soils, and
|
||
ovu-i'nphun.
|
||
|
||
Thesearemeprocsesolsaluusalion or soil salonp.
|
||
ln ms and ma, w, c. lowdei-iuillc ol lhe Uniled
|
||
Sinus Deparunenl ol Agncuhuu casl a soil conserva-
|
||
linuin's eye over whai arelraeolopy had revealed ol lhe
|
||
oocegrarid eirilisaiioru ol lhe Middle Em, Israel, and
|
||
dryland Chm: lu.s ml Bulleiin m ol W29). He
|
||
nored lhe pailerns ol Ibandonmenl ol hillside
|
||
sellelrnenls based on ngrkulm ln rhe semi-arid lands
|
||
he risrled, and lhe lvenmal (ancenm‘llon ul
|
||
secuenienrs on me valley flwrs, in wadls. and in oases
|
||
Many Excavanuna iri llie Saharan arid Thar dcserls
|
||
showed lhal (Instwp c sand flows and sllllng had
|
||
phlireraced lirsl lhe canals Um \rrlgakd lhese
|
||
eel-lame, men lhe seeelenienls thumb/ea.
|
||
|
||
Today, lhousands ol ahandooed men: he buried in
|
||
dark sands, people planled wheel and reaped sail
|
||
an" 7,000 years ol lhrs hlslory urn—repealed. Ausmlla
|
||
and lndia are or. m: same suicidal palh, We lose
|
||
30.non4u,nua ha ol Hub]: land to sali and
|
||
desenilieauon each year, lir lhe Wesl Ausrrallan whear
|
||
be“. lama ha ol larinland is losl l0 sail annually, and
|
||
some 250,000 ha ol salied soils are now noled in
|
||
croplands,
|
||
|
||
in me cenlral Ausuillan deaerl, m. ol lhe land
|
||
lounging in 9% or urcorrie, inosl ol which depends on
|
||
lourisnr) ls devuled |o unregulaled pasroralrsnr,
|
||
producing erosion sears lhal are ionspicious on saiellne
|
||
pholograplu so we proceed lo our own more nioderrr
|
||
erlrnnion and elirrrinalion vra an ephemeral ecporl
|
||
agrieuhure ihai will leauo Ausrnlhnsas a 'lhlrd world"
|
||
pmple in a lcw more decades
|
||
|
||
SALINITY
|
||
|
||
salr is bmughl in by sea Winds, as rim nuclei. (occur
|
||
SALT), irr rernains ui soils and sedinienls liorri inanne
|
||
periods lcoNN/im sam Cyche sal- provides planl
|
||
numenis, hul can also lorrn sali ponds or crusia it
|
||
eraporarecl, as is errdenl in pools on dry, wmdy sea
|
||
eeasls sill is also leached lrorn ruck minerals by
|
||
groundwarer, which carries large loads ol connale salls
|
||
dissolved horn old sea beds in indismroed counlry,
|
||
lhe soils or [crests have horh higher sail and orher
|
||
rnnreral nurrierils, and marry deser- rreeserude er shore
|
||
|
||
401
|
||
|