Abstract:
Forests are found scauered in inaccessible und sacred <>reus u: Ille regio» of Tigray .• -lmo11g these is the
remnant of the dry afromontane JbreSi of Deso 'a. The presence of severe deforestution and fores:
deterioration are well studied in this area. However, no comprehensive research or document is found
;'ttgarding the dynamics ofthe key and Pr.r>")>'st~'?ni dir.w1iJ1g species in. the dry afromontane of the eastern
'escarpment. This study "l'£~s conducted 10 evaluate the spatio-temporal and hP.n/th Jj;:1uJ1n[t·.1,.· '!I Olt~a
europaea and Juniperu .c
in relation to their potential successors (Cadia purpurr:a, Calpurnia
aure<: and Tarciumuruhus campltoraius} ana deforesuaion explanatorc variables between. 1972 and 20UJ.
Key '>-'<rrtls: De$a>a, Forest health, 0-cforcstabor.. GlS! Remote sc:n:sm& Subpixei cia~:;ilivr_, NU\;I> SPSS. /.011.il
statistics. Logistic regression
1?rOcera
ABSTR.:\CT
1'<1 achic.'ve !h~ o~jective set> the power of Ci:,~ and remote ~;(?c.7ng ivus combined ~.·tfh _{}PS~;. Sateitttc
images of three different years (197 !, J 986. and WifJ) .,. e. re obtained and pre-processed for defects such
as atmospheric and sun angleproblems. Imugine Suhpuel classifier, NDVI and SPSS were used ta
classify· species and e;1iu1Cf1E! their respective area change O\.~' the specified times, evaluote {he h~1l1h
dynamics ofshe ji>l< 'P"':it<< and 10 ide111ijjl rile deforestation deriving force> respeaively. ,'{!)VT and
altitutl« values '-1/Cre extracted to each species using the extr<1c:r. values l<> poinisfunction en ,4rcGJSIO. T.?
frlentijy the causes ojdeforesuuion, differe11t socioeconomic and physical data were obtained and logistic
regression tvas run. Accordingly, J. procera and 0. ettr(Jpaea covered 3078/i.a and 3 l 86ha in i 97} 1~·hich
11-ere reduced to 1855ha mu! 2121ha in 2010 In cosurary, both the successors covered 6578/r<l ii! 1971
and 10845ha in 201 G. The 111os1 aggressive specie» from ll1e eariv coionizcrs tvas c:. au;·c!a which showed
continuous Hr~re1ne.'1l between i972 and 201(] .. .J:(J1lpe;11.J procera and Olea eur<1paea "'~re retreating at a
ruu: of'32J,:.t £tttd 28Ju: per year; whereas, the early colonizers, and C. aureu. T. camphoratus, and (~.
purpurea were advancing at a rate uj 56hu, 43ha and i 2ha per ,IN!tlJ'. Produaivitv performance of the key
species 11·a~ <leie,.iuratmg over time. 111e NDYT voiues of 0. europaea wen: 0. 18-0.34 i11 1972 which W<l>
reduced to,JJ.(}4-U.23mu! 0.03-0.25 in i986 and 2010 respectively. Likewise; NDV! values of.!. pmc:,;m
were withi» 0.15-0.44, 0.19-0.33 and 0.2-0.34iJ11972. 1986, and }QI() 1·e.'Pe<:/1vt!(\·. However, os they did
in the area expansion, the early coloniser species were flounshing w11.h ttme. The most benefited from the
degradation process 111 the fore" in terms oftJToduc:ivtl)I performance ll'i1S C. purpurea in which ~7JV!
values progressed .from 0.16-0.41 in 1972 to0.35-1.00 in 20]() though reduction was observed in
• J 986(0.i7-0.32j. ft •va., [ollowed by C aureo, the fastest coloniser. which was <:011til!u"i!v m<.Tea.ving m
pruducfivi:.): rJerj(>rtUtu;ce. Tarchonanthus camphoratus: the most abundant anion!{ th« selected specce«,
wa~ also performing progressivety wirn NDVi vatues Q.08-0.36 it; 1971 and 0.!5-0.29aml 0.19-0.47.
:1 tru>n.~? the fJh;:str.al drivers of aeforesuuion. slope; aituude. distance from 1i(t(ores1ea etige.. road t1t1d
seulement areJ.1s had 11.ega;i'.ve relationship wiilr ikjQJ-estnlit)n rai1~s. I !11i-veFer> asper.1 •t.•as !nsign{ficant.
From tile socioeco11omic factors: age. off fam1 a<tivuy and education Jtm>e negative re.lationsflip mul
family size, Jann ownership and gender (malej, have positi;;e rela1io11ship. 111e accural:V <!f the""'""' of
Suhpixel dc<1,1ijuu1ions were assessed using 500 poinis. JOO for each sp<;cics. 250 poiT!t., '"ere <!xttac1e.d
.from tile ci<lssified map and 250 from g>·ound t<> see mnmussion.~ and omi!isions ?especih·elf. This viefdet!
83% accui-aq ie>,'£1i 1vith 5.2% and i 1.8% cr11mrnssion and omissi-Ons respectively. Tlte los~ of i!ie k('r
species inlf:rm-; ()j ltrc:c; c:t>r ·~rus,._.!, health status ru:d aliilutie constrictia1: is tiz1·e(1tening ii~ ~·t t·onti111.t:~li at
/his rate. ,\,foreover, they are heing replaced by (fie fess eco1w11:ic shrub >pecics which woo/J creaw a
.•·hruh dominared rtcosysrem i1; the near future. T'ni.s. c.fter all. could potenlial(v boost the (?111'i•·o11111rm;a!
crisis and socfoecoJ:otnic disorder in the li1C:nl r..1Jlitmunity t-vht~r1: hi>,'rir de1>enden0: 01i Lhe ji)rest (n1ainl_i,.•
011 the key species) is observed. l'hereforrt, inler\.'lmtir>n.1· !mdt as implememal1on exisiing laws .wd
reg-.Jlafi<JJL.\' anti zero gruzinu ure needed .!O as to 1nain1ain this multi-in1p-0rtant jOresr patc