S. Afr. J. Bot. 1998,64(1) 1- 17
Vegetation ecology of the southern Free State: Shrubland communities of the rocky outcrops
P.W. Malan " H.J-T. Venter and P.J. du Preez p.o. Box 292, Mafikeng, 2745 Republic of South Africa
Received 20 Fehruary f 997; revised 28 Juzv /9!r
A phytosociologica[ analysis of the vegetation of the rocky outcrops of the southern Free State is presented. Releves were compiled in 185 stratified random sample plots. A TWINSPAN classification, refined by Braun-Blanquet procedures, resulted in 35 plant communities. All these communities have ecological similarities and diffe rences as pomted out by the DCA ordination. The described communities serve as a basis for their spatial distribution in this area as well as for determining their conservation status in the face of increasing development and agricultu re.
Keywords: 8rau n~Blanquet vegetation classification, DECORANA ordination, habitat re la ted, rocky outcrops, southern Free State, TWIN SPAN .
• To whom correspondence should be addressed.
Introduction Methods The Grassland Biome in South Afri ca is under heavy pressure Releves wen:: compiled in 185 stratilicd random sample plots. Sur from several different forms of man induced activities (Du Preez veys v,·ere do ne during the summer and late summer of 1993 and 1991 ). To enable optimal resource ut il ization and conservation, a 1994. Stratification was hased on rainfall, topographical po ~i tion vegetation classification program has been implemented in the (slope. crest and plateau). soi l form and geology. No care was taken Gras sland Biome (Mentis & Huntley 1982; Scheepers 1987). to place sample plots in st:!vere ly degraded areas. Plot sizes were 2 This survey was planned to provide data for the synecological fixed at 100 m (Scheepcrs 1975). In each sample plot a list of all syn th es is of the Grassland Bi ome Project (Scheepers 1987). species present was compiled and the cover-abundance of each spe Attempts to conserve biotic diversity are pointless and impos cies noted llsing the Braun-Blanquct scale (M ueller Dombois & Ellenberg 1974). T!L'\a names conform to those of Arnold lind De si bl e if the entities contributing to diversity are not known. Plant Wet ( 1993). No dist inctions we re made between different subspecies cOll1mun ities are conceived as individual, recognizable entities except for Euclea crispo sl1hsp. crisp!1 and Elle/ea crispa subsp. (C'oetzee el al. 1993) and are characterised by thei r fl ori st ic com ovalo. According to Vcnkr and Jouhert (1985) the In ttcr is mainly pos ition (Whiuaker 1978). Because the natural vegetation of the distributed through th e dr ier ridge vdd of the sou thern Free State. rocky Ol1tcrops in the southern f ree State is clearly adversely while Euclea crispo suhsp. crispo IS common to abundant in the aftected by past and existing farm ing practices as well as contin kloof forests and rocky habitats in the moist areas in the southern uous urban development (Furs 1993), a detailed study of these Free State. This is con ll nned by Malan et 01. (S ubmitted). Euclea areas is long overdue. crispo subsp. ovata is referred to as Euclea crispa whi le Olea eIlro~ The main objecti ve of thi s study was, therefore, to classify, paea subsp. ajricana is referred to as Olea ellropaea in the text. All describe and ecologically interpret the shrubland communities of the reference spec imens are hOllsed at the Gt:o Potts Herbariu m at the rocky outcrops in the southern Free State. These data should the University of the Orange Free Swte. Other relevant information be of importance for ecologicall y sound resource management, such as habitat disturbance. degradation of the vegetation, rockiness planning as well as for the identification of possible conservation of the soi l surface and hum an impact 011 the habitat were also noted. areas, especially in the urban areas. Soi l depth was determined by driving a marked steel pin as deep as possible into the soi l. Two~way indicator species ana lysis (TWINS PAN) (Hill 1979a) Study A rea was applied to the Iloristic data set in order to derive a first approxi The area studied is si tuated in the southern Free State west of th e mat ion of the vegetat ion types of the area. Refinement was dOll e by 60()-ROO Illlll rainfall interval and is bounded by 24° 20' and 27" means ofBr au n~Bl anquet procedures (I3reden kamp et at. 1989). The 00' E longitude and 29° 00' and 30° 50' S latitude. Plant commu nities east of the 600-800 mm rainfall interval are discussed else where (Malan ef at. Submitted). Towns situated in the study area are (from north to south) Bloemfontein, Petrusburg, Fauresmith, - 29·S Wepener, Zastron and Bethu lie (Figure 1). In this area, wetlands r-:::...,e...g. 17 '. f - ,""'- ~ are mostly represented by streams, rivers and vleis and are ~ N ";& _m .. ""or.I!' .. ... • ~" 7 mainl y found in bottomland situations. The area covers approxi , 2 . ·'",c."",n wt~, '\ mately 26 000 km Permanently waterlogged soil s are scarce -'- JO ·S \ and seasonally standing water is mostly restricted to s l ow -drain~ --~,. ing watercourses and drainage channels. Slow-draini ng st reams '\, 'l .." • are t.:omlllo n owing to the flatn ess of th e terrain over most of the " ~ -~D study area. • ~ 100 ~'" The rai nfall is erratic, especially in the western part of the r= I I stu dy area and increases in an easterly direction from a 300-400 mm per annum rainfall interval to a 600-800 !TIm per annum Figure I The location of the study area in relation La towns ill the rainfall interval. southern Free State. s. Mr. 1. Rot. 19n. fi4( I)
tloristic data set was further subjected to an ordination algorithm 1.2 Buddleja saligna- ElU.:/ea crispa Community (H il l I 979b). 10 determine habitat gmdients and the relationship with J .2. J Opl/nlia ficll .~·- illdica- Blidd/eja salignQ Sub-community. cnvironrnl!lltal variables. 1.2.2 Hermannia b,),olliijolia P(lwmin Imrchellii Sub-community. Results and Discussion 1.2.3 May tenus po/yacantha· Bllddleja ,W/ligna Sub-community. The vegetation of the rocky outcrops of the study area generally 1.2.4 Pupa/ia lappac·ea -Lantana rllgosa Sub-community. has a low species diversity (See Table I ), but contains a variety 1.2.5 Aloe broomii- 71wmeda Irimu/ra Sub-community. of trees, shrubs, herbs and forbs. The general vegetation of the 1.2.6 Triraphis andropogonoides- /Jmld/eja saligl1a Sub-communi ty. rocky outcrops can be classified as the Themedcllriandra- Eliclea 1.2.7 Buddleja saligna- Themeda f,-i(lnelro Sub-community. cri,\pa Shrub land. This vegetation can be divided into two major communities, namely shrub land vegetation of hills and ridges 1.3 Tarchonanthus camphoraflls-Themeda triandra Community. (Major community 1) and dwarf shrubland associated with flat 1.3.1 Digitaria eriallllw- TarehOlUlI1llll1s camphoratus areas on the plateaux of hills (Major community 2). Sub-community. The shrubland of the hills and ridges can further be divided 1.3.1.1 !-lermmmia vestita- Prota.vparagus capel1sis Variant. into four di stinct vegetation types: 1.3. 1.2 Se/ago albido- ()xalis comir;lI/ma Variant. I 3.1.3 Light/oOlia albens- Euslachys paspaloides Variant. 1. J shrubland of ravines and south- and east-facing slopes; 1. 3.2 HelichryslIlll =eyheri- Themeda Iriandra Sub-community. 1.2 shrllbland of the drier north and west-facing slopes; 1.3.3 Euryops mulllfidus-TarchOlulIll/llIs camphm·ofll.'i 1.3 shrubland of the dry, overutilized and disturbed crests and Sub-community. plateaux; and 1.3.4 Rhigo=um ObOl'alllJ11- J'urchVllClnthwi cGmphv/·a/u.\" J.4 shrubland of low hills on north and west-facing slopes. Sub-community. The most abundant woody species associated with the hills 1.3 .4.1 Slipagroslis l1amaquel1sis- Rhigo=unJ ohOl'OIl1111 Variant. include Olen ellropuea, Grell'ia vccideJ1lalis (species group K, 1.3.4.2 RhigozllIn obovatum-Heteropogoll cOJ/lorlus Variant. Table 1), Buddleja saligna (species group Q), TardlOnanrll/{s Community. camphoratus (species group Z), Em'lea crispo, Rhll ,~' erOSQ, Feli 1.4 Elldea crispa- Themeda trialldm 1.4.1 Euclea crispa- Tragus berlervniaJlIl.\· Sub-community. cia fi/i/olia, Diospyros austro-a.!ricana, £hretia rigida (species 1.4.2 Setaria sphacelala- Rhus ciliala Sub-community. group AF). Rhus burchellii, and R. ciliata (species group Al, 1.4.3 Phyllanthus parvuhls- SeSal11uII7 capense Sub-colllmunity. Table 1). 1.4.4 Kleinia longifolia- Themeda Jriandra Sub-community. The grasses, DigiJaria eriantha (species g roup U) and £us 1.4.5 Cymbopogon excavallls- Euc!ea crispa Sub-communily. tachys paspa/oides (species group T) frequently occur in open 1.4.6 Euclea cr;spa- Arislida diffusa Sub-community. shrubland. but are limited to the low shrubland vegetation. Graminoids such as Themeda lriandra and lieferopogon conlor 2 ivlohria caffrorum- 7hemeda triandro Major-community. Ius (species group AJ) are conspicuous throughout the entire 2. 1 Eberlan=io spinosa- Mohria caffrorum Community study area (Table I). 2.2 Fdicia maricala- Mohria ca.ffrorllm Community. Dwarf shrubland associated with flat areas on the plateaux of hills occurs primarily under dry conditions, is virtually unpro Description of the communities tected from v·lind erosion, and is restricted· to only a few shrubs 1 Euclea crispa-Aristida ddfi/sa Major Community and dwarf shrubs such as Rhus erosa, R. ciliata, Eberlanzia spinosa and Febcia '!lUricata as well as the small fern, Mohria This shrubland occurs mostly on the southerly and easterly fac caffrorulII (Table 1 ) . ing slopes of hills and ridges and also within ravines and drain The vegetation is classified into 35 distinct plant units (Table age lines or depressions on northerly facing slopes. These slopes 1). The hierarchical classification of the two major plant commu are relatively undisturbed to mildly disturbed and/or overgrazed. nities of the shrub lands of the rocky outcrops of the southern The most common, often dominant, woody species encoun tered is Euclea crispo (species group AF, Table 1). This species Free State is as follows: is widely distributed on the rocky outcrops of the southern Free 1 Ellclea crispa-Aris/ida diffusa Major Community. State (Venter & Joubert 1985). Accord ing to the Tree Society of southern Africa (J969), £. crispa is one of the most COlll lllon 1.1 Olen elll"opaea- Buddleja saligna Community. trees throughout South Africa. The shrubs, Rims erosa and 1.1.1 Crassliia lanceolata- Buddleja saligllo Sub-community. Diospyros austro-africana (species group AF) are also fre 1.1.2 Cllssonia panieillata- Mayletius heterophy/la quently encountered. Rhus burchellii (species group Al) is the Sub-community. most common shrub in rocky ravines and 011 outcrops. Grami 1.1.3 Diospyros Iycioides- Buddleja saligna Sub-community. noids include Arislida diffllsa, Sporobolusjimhriallls, Cymhopo 1.1.3. 1 Tllrhina oenotheroides- Diospyros /ycioides Variant. gon plurinodis, Eragrostis ellf'mla, Eliol1UrliS m1ftic/(.\" (species 1.1.3.2 Cussonia paniculata- Diospyros Iycioides Variant. group AF), Themeda Irial1dra, and! /eleropogon con/orllls (spe 1.1.3.3 So/allum coccineum- Rhus burehellii Variant. cies group AJ, Table 1). 1.1.3.4 Olea europaea-Diospyros Iycioides Variant. This shrubland is further divided into fOll r distinct plant com 1. t .3.5 Rhus /aneea-Diospyros Iycioides Variant. munities (Table I). 1.1.4 Rhus lancea- Buddleja saligna Sub-community. 1.1 Olea europaea- Buddleja .mligna Community 1.1.4.1 Acacia karroo-Schinus molle Variant. . J .4.2 Rhus laneea-Olea europaea Variant. This shrubland commonly occurs as scrub on rocky places and .1.4.3 OJyris lanceolala- Rhus laneea Variant. ravine areas. The aspects are mostly southerly and easterly. The 1.1.5 Osyris lanceo/ala- Olea ellropaell Sub-community. habitat is generally cool due to the shading of overh anging cliffs. 1.1.6 Zizip/llts mueronata- Olea europaea Sub-community. moist and undisturbed. Areas of fine gravel, due to continuous 1.1.7 Olea europaea-Buddleja saligna Sub-community. erosion. give the soil a stony appearance. This shrubland also S. Afr. 1. Bot. 1998,64(1) 3
Table 1 Phytosociological table of the shrubland communities of the rocky outcrops in the southern Free State
Plant community number .1 .2 . 1 1.2 . 3 .. . S . , .7 .1 . 2 . 1 .2 1.3 .. .S .1 I .2 .3
1222135515555 1222252 12231433545412323341333144224415545134346232212222231331433356623132112333144421 Relcve Numtll;!r 1667177718888 1698989 1772 189585121267661166616519661175719374011991812994 123642541001011799810718855 1 1341 1867 1103215381421265 12625882121079814561401023168991427747768 1921549 1634631075136 1335365521784 71
Number of s pccics/Releve 1110 121111111111111110111121110111111011111 1010100 111111111110110 11111111011100001100 100010001 10000 1 1627116611001152321217011511018212011871200 174816811582147436923912325401902288875387167708650 197771
SPECIES GROUP A
eras suI a l a nccolata 11131 1 R 1 +
SPECIES GROUP B
Brunsvigia r adulosa 1= 1 Haytcnus hcterophylla IRll l TalinulII caffrulII IR+RI
SPECIES GROUP C Turbina oenQthcroides I+A. 1<.1 1
SPECIES GROUP D CUssonia pan1culata 111111221 1R2RRlR I R 2 R RI
SPECIES GROUP E
Solanum coccineum 11 1+ 11 12111 1 1 Rli
SPECIES GROUP F Diospyros lycioides I 211 1 122 1:RR2:121321221222111 1 1 2 1
SPECIES GROUP G Acacia karroo 2 11 11231 IRl Sch1nu5 mol Ie 11 12221 11
SPECIES GROUP H Rhus lancea 4 11 1 111112212211121322 12432 1 11
SPECIES GROUP I Osyr1s lanceolata IR 112221111122221121
SPECIES GROUP J Ziz1phus mucronata 11 2 2 1 11223131 Cotoneaster species 1 + 1 111 RI2 RRR I
SPECIES GROUP K Olea europaea 1225134 1133231312 5 11331R2 1322123 134312243 12222111131 44153333 1412241121232 1
Viscurn rotundifoliulII I R IR IRRAA RI RI + 11<. R I RR 1 11 R IRRAA III R Grewia occidental is 12221 12 12R 11 12 11 1111 1312 1 RI Opuntia f1cus - lndica It IA. IR +1 R1 11 11 2 2 1 I R R 1 1 1 R I 2112R12RlR2 1
SPECIES GROUP L Hermann1a bryoniifolia 11 RI 13332 1 Pavon1a burchell1i IRR R RI R 1 1 + Rl1 R 11 1221 Senecio consangulneus 1 1111 Helianthu5 comosus 121
SPECIES GROUP H Hay tenus po1yacantha 1 1R RI 1 R Ril R " S. Mr. J. Ilot. 199M. (411)
Table 1 Continued
SPECIES GROUP N Pupalia lappacea
Lantana rugosa R R R I + R " R 11 Solanum retroflexum I + Chenopodium ambros1oides Schkuhria pinnata H1b15CU5 trionum IR IR R Setaria verticillata Chenopodium album Cemmel!na benghale nsis
SPECIES GROUP 0 Aloe broo:'l'l.1i 11 R Indiqofera ses511if olia 1 Nenax microphylla
SPECIES GROUP P Triraphis andropoqQnoides 12221 I 1 I
SPECIES GROUP Q Buddleja saligna 143413211 25115454531 43 1 43223 1 331231323 11233 1122121 22222235 132 33 13123331322421323224431111 I
SPECIES GROUP R Hermannia vest! ta Protasparagus capens1s IR R
SPECIES GROUP S $01a90 albida + Oxal1s corn1culata I RR Walafrida saxatilis 11 11 Crassula nucl.1caulis R Pelargon1um abrotani!olium
SPECIES GROUP T Lightfootia albens Eustachys paspaloidcs 11 2 1
SPECIES GROUP U Digitaria eriantha 1R2 121 11 I 1 11 2 1 1 I 11
SPECIES GROUP V
HelolObium candicans RI 1+ R R Hclichrysum zcyhcri Maraca spathulata ArgyrolObium pauciflorum Plcxi pus pinnatifiaus I +
SPECIES GROUP W Euryaps multifiaus 4
SPEC IES GROUP :x:
Stipaqrostis n~quensis Berkhcya pinnatifida
SPECIES GROUP Y Rhigozum obovatu. I 3 2
SPECIES GROUP Z Tarchonanthus camphoratus 11 2 11 2 3 221 11
SPECIES GROUP AA Tragus berteronianus
SPECIES GROUP AB Setaria sphacelata S. Afr. J. Bot. 1998,64(1) 5
Table 1 Continued
SPEC IES GROUP AC Phyllantbus p a rvulus IR Sesanrulll capense 1 Scilla nervosa
SPEClES GROUP AD Klclni a longi!olla
SPECIES GROUP AE cymbopoqon excavatus
SPECIES GROUP AF
Euelea crispa. sUbgp. ovata 133 121221 Rl121 111421 1 1121 2 12 2 I 2222 2 11 R.31 322 1 33 1 1 12 21 I 11 ~lstlda d1!fusa. 11 1 1 12 11 11 2 I RI Rhus erosa 2 14341 12 2222 43 53 12223 12 2 1 11 31 Sporobolus fimbriatuB 11211 IRl 21 1 1 "I 1 111 1 2 11 cytnbopoqon plurinodis 11121 11 121 12 1 1 Protasparagus strla.tus 11 IR IR 11 2 11 121 1 2 R R 2 R 11 + 1 2 Ehretia rlg1da rul 11 1 21 1 2 2 ><21 Ennea.pogon scoparius 2 I 31 2 Il 5 3 Cheilanthes ecklon1ana IR+ 1+Rl. 1 IIUl. RI +IR + I + R+ 1 FeliCia. filifolia. ZI IR lR 11 1 111111 11 R 111 Rl 2 1 2 2 1 Dlospyros austra-africana 1 1 11 1113 1 t 12 R 3 1 RI Eragrostis curvula. Il 21 1 I Elionurus muticus 11 1 I 11 2121 2 1 R
SPECIES GROUP AD
Ebcrlan~la spinosa
SPECIES GROUP All Felicia muricata 1 I Il + 1 1 1 1
SPECIES GROUP AI Mohr!a. caffrorulll 12111 IlRR R R III 2
SPECIES GROUP A,J ThemedA triandra. 1122 12 2 21233142 I 1 24 21 1 1123:3 1 134 21 222121224 13 2 3 342 22224144335522 122 Heteropoqon contortu8 11111 1 R 1 I 1 1 1 31 2 1 1 I 1221 3 1111 31 2 Rhus Durettell!1 123 12 132231 3 22 1132 112 11 2 1311 1 12211 133 12 1414222 1312 32 412 12 121 3 III Rhus ciliata 111111 1311112 1:312( 22 111+ 111 31 I 311RI 232 22 131221 Protasparagus larlcinus 11R 111 121 R 1 I 1 11 ru 1 ZI RRll 11111 1 "I Protasparaqus suaveolens IR 11 1 1 1111 1JR 1 + 1 R 1 11 R 1 1 1 Aristlda congesta 11+ 1 11 R 12 R 112 1 Pellaea calomelanos R +1 R IR+ R R 11 Chrysocoma ciliata 112112 2 1 11 R R R +l IR Sta.chys rugosa IR R 3 R 12 2 Eragrostls lehmanniana 122 11 Il 2 11 112331 2 211 22 6 S. Arc. 1. Bot. 1998.64( 1)
Table 1 Continued
, , , . , 1 ., . 2 I 31 3 I 4 I 5 I 1 1 2 1 . .3 I 1 1 21
444 ]36 I 555555 1 4444 I 325232 1 ]]$4333532225 1 333 1 )333 14554 11111 6021111 111 1 144444 I ] 3 33IZZ21 11111 I <1 H 4 I 4133 22521342 I 33333 I 23233 I
566221 100000011222 I 078808 I 47810171115011 776 I 9899 I 40141889 I 010 I 777 I 335 I 42214 14000 11127 I 6667 I 4652 I ~343 55157357123)34 I 61524 I 701780 I 345682 1 9143 17483811107]9615041]313421 0512159081781129613211 977 125060 I 323416906 I 57651 HIZ8 1 018S 2411 7739 I 90212 1 0861 71
llymbcr of species/Relev"", 11 1 00011111111 ~1l1 1 0010011 0011001001101 III I 12112 11111 '1111100 loao I 000 111 000 11000 111 10 I 0000 I 0001 1 HOI 00000000 I 00000 I 00100 I 30 76591964266 I 49n I 761970 I 6910550740070 I B651 02721 557616411 047 1769 I 558 1247691 0179615239 1 8n8 I 988311291 96699986 16670187188 1
SPECIES GROUP A Cr;ts sul;t lanccol ata " SPECIES GROUP S SrunSV1<}1'l radulos .• tiaytcnus hctcrophyll ;t T;tllnum c .. [[rum M I "
SPECIES GROUP C Tu rbu •.• oenotheroldcs IR "
SPECIES GROUP 0
SPECIES GROUP E Solanum COCClnCUm • 1M " " " •
SPECIES GROUP F 01ospyros lyc101des 1 , , " ' " "
SPECIES GROUP G Acac1a )oarroo Schinu" molle
SPECIl!S GROUP H Pllu" lancea " 1 ,
SPECIRS GROUP OS)'r15 lanceolata "
SPECIES GROUP .J Z1z1phus mucronata 1 I 1 I R " Cotoneaster specles "
SPECIES GROUP K Olea europaea V1scum rotundi{oll.um Gre.,ia occidenta11" Cpuntia f1cu,,-l.ndica
SPECIES GROUP L Hermann1 .. bryonl1folia Pavon1,. !:lurchel.l1i senec10 con"anqu1neus Hel1anthus CO""'SU"
8PZCIB8 OROUP H Haytemu polyacantha lUIR2lll Illll I S. Afr. J. Bo l. 1998. 64( I) 7
Table 1 Continued
SP!;CIES GROVP N PUI':l lli\ 1;\1'1''''''''' I AAAAll l L.lnt.\n" r U905.:1 • I PAR R I R OR' SolAl'lu", .. ctfO(lCXUln I AAR RR t ,. " Ch"nopo(llllm 1ImDroslol.dc" IAARlR I
S.;hkuhrl.l plnn.'t.\ 12 2121 'RR Hlbl'CU~ t r lOl\II'" I R AA I I R R I set,.r,,, vert1elll.].';11 "'" ChcnopOdlUrII ,,1 bum I lR R I . , COII';nCllna bongh.l len sls RR
SPECI ES GROUP 0 Aloe O(OOlU l IRUU I I ndll,lo(<:r" U!lI5l.hfoll') >0 , RO I 2 I 1 lien .. " mlcrophyU" R> , , , •
SPECIES GROUP P Trlr.>.phl s anCiropoqonoldcs 1122223 I I 211 1 '" jl 11 SPECtES GROUP Q
Buddie)" " a l.g" .:I. 3334321 33J233 1221 132423 123512421333111 RO
SPECI ES GROUP R.
Hcrm.,nn,a Vestlt" AAI R t Prot.>sp.lr,l'1'l S " "pcns'5
SPECIES GROUP S ScLl<.lo "Ibid" I R R I ., IRRRR I R R I OR OR .. OX,,11!! cornl cui", t .. R RIR AA I R IAA W-al .Hrl-Ciol 5<>'X.:I t1115 I R AAI I R 1 1 , , Crolssul.l nlldle,u,l,s t R I R R Pel,u9'0nlum a.brot:mlfoll\lm , RR
SPECIES GROOP T L lghtfoot:1.l IIlbcn .. I +R t RIIR+1 1 , . EU5L,\chy" p""p:.lOldcs IRt 111 >oR" 11R t t 121IAA I I IR 1 , ,
SPECIES GJU)UP U 0 191tll" '" "f'.lnth", t 42 I 2 1111 12 1 2 I 2+1 1 1 I " , 12 1 2
SPECIES GROUP II
Helo lolnu ~ ""nen"an" RO' IRRR t 1 1 R R I JIll He l,cl'lfysum ;:cyher, ,MR' tior.J.ca sp
S?£C !ES GROUP W Euryopi multlf1dus 12211
SPECI ES GROUP X S tlp,1,grostul n;un:>.quen"l.l (222 1 Serkhcy" pl.nn" tlfl.d.>. , , 11111
SJlEClES GROU P Y iUuqo:um obovil tum OR 14~512 22 1 I J 1 I I 111 I
SPECIES GROlIP Z T",ro:honanthus e ... mphol::iltu s " 12131131112113 13J2 12221221 1231 1
SPECIES GROUP AA Tr SPECIES GROUP "'-B SctOlrl Table 1 Continued SPECIES GROUP AC PhylLlnthus p .:u"Vulus R ,. I llR Se.samum Cil.pcns ,", RI R I," SeliLl nervosa I ~I SPECIES GROUP AD Kl"1.rl1-a 10ng1£oIla 1112 1 I Rllltlil l SPECIES GROUP AX cymbopogon e xcavatus I , I 1 111111 SPECIES GROtJP AF Euclea CrL'Ip a s ub.$p ovat .. :: 1 312 1133212 1 113152 3Rl 221123 13)421]112 1111112 11 22331321112333 13322 I 2233 I 3333 24232333 1 R Arlstlda chEfu ... ,\ IR :: I I R +111112131 1211 I 11 21 I R 2 1 2 123 113211 12:212 Rh,u erosa 12122 1 12121 )1 11213 121 21 " 3 241 Sporobolu5 Elmhn.atus I IR2R21 1 111 J 21111 I II lU I INUI '" 11 22 11 22123" , I Cymbopoqon plurlnodls " , . , I I I IlUt 12lU R I Protaspara9"s striatu ... '" " , I n , , . 3 1 1 I 1 I 4. I" 112 1 Ehret,-a rl.gida , I R , , I '" R Enncapogon 5COP"tl.US IR R R ~I " " Chellanthes eoklon1an" I R+R I IR IRAAR11R+11 RI 13311 RR R IR "1 , R R Fell-Cla f'lilfolia I R 21 IRl2 1 1 RI 22 , , Dlospyros "ustro-aiel-c.l"" 1 21 1 I "I , " " " , I I '" E""'grostl." curvul" I 22 I , I " I n " " El~onuru s mut~cus 11 1 IR 11 '" 11 1111 '" " SPECIES GROUP AG Ebe rL~n:a:>, sp~nosa 112233 I SPECIES GROUP All f'cll.c ~a muricat'l I , " I 223Rl I SPECIES GROUP AI Mohr.a c.~{frorum I 1 2 R i l R 14443212AAllI SPECIES GROUP AJ Thorned:>. trl:>.ndr a 221 24 1 13232 ( 31415132222131221121112332(5551141 3 122 23 1 4 3 1 11223111 2 12 52 R 11211 RI 2 23 1 Heteropo90n contortus , , 121 1Rl2 1133 I 113421111 1 1332 12 2331 111 2 12 2 12 3 12122 13 12 21 Rhus b u rchelill 2 1222 IR 2322 1 .2 2 21 32 52 R 4 2111111 121111 2 12 2 1 I R Rh us clll.:>.ta , ,. I 4 2 1 1 1343 IRI I 14" 21 1"3232 12 3231 22 4141 21 R4 3 4. 3 1 j 35 Pr o tasp:.r:.gtls lar.Clnus I 111 " 1112 1 Protasp:'J;".lgtls s uaveol.",,; R 1 1 1 R R I 11 I I~RI 11 11 IU I , AJ:lstlda conges ta , RI I R IR RR I I~I I , I , 11 22 P011ao:>, caloroclanos l AAR RRIR " RI R I IR R I I R 11 R I R Chrysocom:>, cillata I , 11 221 I , 121 1 I 2 stachys rU90sa 111 1 2R R ,3 1+111 121+ IR RI " R ill " R "I , I , , Er.~gro s ti s lehmannlana 12 2 1 " , I , I s. Afr. l. Bot. 1998,64(1) 9 occurs on the gradual foots lopes of hills and ridges. The soil here 1.1.3 Diospyros /ycioides- Budd/eja saligna Sub-community is generally deep (> 100 mm deep) and ofthe Avalon form with a clay content of often higher than 35% (Macvicar el al. 1977). This plant community is found on the middle and lower half of Trees and shrubs are totally dominant within this plant com south-facing slopes and within drainage lines or depressions of munity. The differentiating species are listed in species group K east-facing slopes. It is also common in ravines and along water (Table I). Bllddleja saligna (species group 0) and Olea ellro courses. The soil is generally rocky, except along the water paea (species group K) are the most common tree species courses where clayish soil is abundant. present. The most locally conspicuous shrub is Grewia occiden Diospyros lycioides (species group F) differentiates this vege (otis (species group K) which has an average height of < 3 m. tation unit. According to Coates Palgrave (1984), D. lycioides This species generally does not have a high cover-abundance, occurs in almost all types of habitat and can reach heights of up but is widely distributed, especially in the dense ravine areas. to 7 metres. The tree, Olea europaea (species group K) has a low Euclea crispo (species group Af) frequentl y occurs and is some cover-abundance value and often reaches heights in excess of 5 times very abundant in rocky habitats. The shrub, Rhus burchellii metres. Buddleja sa/igna (species group Q) is very abundant, (species group Al), is also very abundant (Table I). especially in the Cussonia paniculata- Diospyros /ycioides Vari Amongst the graminoids, Themeda triandra (species group ant (Table I). Euclea crispa (species group AF) and Rhus AJ), is by far the most conspicuous. Other grasses which also burchelli; (species group Al) are the most abundant shrubs commonly occur include Heteropogon contor/us in rocky habi present (Table 1). Grasses are absent from this community with tats, Aristida congesta and Eragrostis lehmanniana (species the exception of Themeda triandra and Heteropogon contortus group Al, Table I) which are commonly associated with over which have wide distributions (Table I). grazed and disturbed habitats (Van Oudtshoom 1991). Five distinct vegetation units further characterize this The semi-parasite, Viscum rotundifolium (species group K) is a sub-community (Table I). stem parasite which occurs most frequently on Acacia karroo, 1.1.3.1 Turbina oenotheroides- Diospyros lycioides Variant Buddleja saligna and Ziziphlls mucronala. This vegetation unit comprises seven distinct sub-communi This variant is restricted to lower south-facing slopes. The habi ties (Table I). tat is marginally less rocky than that of the Cussonia panicu/ala Diospyros lycioides Variant and the soil is clayish. Runoffwater 1.1.1 Crassula lanceolata-Buddleja saligna Sub-community from upslope causes accumulation of water, especially in the This is a very limited plant community which is restricted to low-lying areas so that standing water is visible for virtually shady areas of ravines at the footslopes of south-facing slopes. weeks after good rains. The soil is rocky and large boulders (>3 metres in diameter) This variant is differentiated by the scanty occurrence of Tur occur randomly. Rock slabs virtually cover the soil surface. The bina oenotheroides (species group C). Conspicuous species are habitat is moist and cool with overhanging cliffs causing mini limited and restricted to the woody species Cussonia paniculata mum exposure to direct sunlight. (species group D), Diospyros Iycioides (species group F), BlId The small forb, Crassula lanceolala (species group A), char d/eja saligna (species group Q), Euclea crispa, Rhus erosa (spe acterizes this sub-community (Table 1). Bllddleja saligna (spe cies group AF) and R. burchellii (species group Al). cies group 0) and Olea europaea (species group K) are the only An average of II species/releve were recorded for this variant conspicuous tree species. The small fern, Mohria caffrorum (spe (Table I). cies group AI), which often grows luxuriously in this rocky habi tat, is also abundant. Shrubs are scarce and restricted to Grell'ia 1.1.3.2 Cussonia paniculata- Diospyros /ycioides Variant occidentalis (species group K), Rhus burchellii and Prolaspara This variant is restricted to the midslopes of south-facing slopes of gus {aricinus (species group Al, Table I). rriraphis andropogo hills and ridges. The gradient is sometimes very steep (> 70°), but 0 noides (species group P) and Eragrostis lehmanniana (species generally varies between 20°_50 with a rock cover of30--60 %. group Al) are the most common graminoids present (Table I). The Cussonia paniculata- Diospyros lycioides Variant lacks An average of 12 species/releve were recorded for this exclusive diagnostic species with the absence of species from sub-community (Table I). species groups A, Band C also being evident (Table I). Cusso nia paniculala (species group D), generally not exceeding two 1.1.2 Cllssonia panicu/ala-Maytenus helerophy//a metres in height. is widely distributed, but has a low cover-abun Sub-community dance throughout the entire variant (Table I). The high This plant community is restricted to the upper half of south-fac cover-abundance of Bllddleja saligna (species group 0) and ing slopes where large dolerite boulders are common and the Olea eUTopaea (species group K) is characteristic. The stem par habitat is moist and cool. The diagnostic species (species group asite Viscum rotundifolium (species group K) is semi-parasitic B, Table 1) and Talinum caflrum especially grow randomly in and is associated with Olea europaea (species group K) and Bud clayish soil in the shade oflarge boulders (generally >2 metres in dleja saligna (species group 0, Table I). Other less comlnon diameter). woody species include Diospyros /ycioides (species group F), This is a poorly developed plant community with all the differ Grewia occidentalis (species group K) and Rhus burchellii (spe entiating species having a low cover-abundance (species group cies group AI). Graminoids are scarce and are virtually restricted B, Table 1). The most abundant woody species are Cussonia to Themeda Iriandra (species group Al, Table 1). panicu/ata (species group D), Budd/eja saligna (species group This variant recorded an average of 13 species/releve (Table 1). Q), Olea europaea (species group K) and Euclea crispa (species 1.1.3.3 Solanum coccineum-Rhlls burchellii Variant group AF). According to the Tree Society of southern Africa (1969), c. paniculala commonly grows in the open, preferring This vegetation unit is common on the mid slopes ofsouth-facing dry situations. This was not the case here as the habitat is cool hills. The soil surface is rocky with large boulders (> 2 metres in and moist. Themeda 'riandra and Heteropogoll conlorlus (spe diameter) occurring. Fine sandstone, due to continuous erosion cies group AI) are the most common grass species (Table I). of dolerite, is common and often causes a slippery soil surface. An average of 18 species/releve were recorded for this Virtually the whole vegetation unit occurs in the shade of sub-community (Table I). Buddleja saligna and Olea europaeo. 10 S. Arr. J. Bot. 1998, 64(1) Exclusive diagnostic species are absent, but the vegetation Acacia kal'roo, together with the exotic Schinlls molle (species unit is differentiated by the constant presence of Solanum cocci group G), differentiate this variant (Table 1). According to Carr neum (species group E, Table 1), Also conspicuous is the (1976), A. karrao is more widely distributed than any of our absence of species of species groups A- D (Table I). Abundant other acacias. A _ karroa in the Free State is usually a single- or species are scarce with only the trees, Olea e1tropaea (species several-stemmed tree, branching well clear of the ground to give group K), Buddleia saligna (species group Q), the shrub, Rhus a rounded outline and having a height varying between 5 to 10 burchellii (species group Al) and Karoa encroacher, Chryso metres. A variant from the North-West is generally similar when coma ciliata (species group AJ), worth mentioning (Table I). C. seen from· a distance but tends to be somewhat smaller (Carr ciliata, especially, is a sure sign of pasture degradation. 1976). Schinus molle is a hardy foreign tree from South America This variant recorded an average of 9 species/releve (Table 1). that has become completely blended into the landscape of the more arid areas (Venter & Joubert 1985). 1.1.3.4 Olea europaea- Diospyros lycioides Variant Rhus loneea (species group H), Olea ellropaea (species group This variant occurs on the lower half of slightly south-west-fac K) and Buddleja saligna (species group Q) dominate the vegeta ing rocky slopes. Large dolerite rocks (> 4 metres in diameter) tion. The only abundant shrubs are Rhus hurchellii and R. ciliata occur on the soil surface and the habitat is drier than the Solanum (species group AJ) with Themeda I,-iandro and Eragrostis leh coccineum- Rhus burchellii Variant. manniano (species group Al) being the most abundant grami This vegetation unit also lacks an exclusive diagnostic species noids (Table 1). group (Table 1), but it is rather characterised by the absence of This variant recorded an average of I I species/releve (Table t). Solanum coccineum (species group E) as well as a slightly higher cover-abundance of Diospyros Iycioides (species group F). 1.1,4.2 Rhus loncea- O/ea ellropaea Variant Prominent trees include Olea europaea (species group K) and This vegetation unit is restricted to the gentle (5°_ 10°) west-fac Diospyros Iycioides (species group F). Among the shrubs, only ing slopes. The soil is shallow « 100 mm deep) and more rocky Buddleja saligna (species group Q), Euclea crispa, Rhus erosa, than in the Acacia karroo-Schinus malle Variant. Fine gravel Felicia fil!falia, Diospyros austro-africana (species group AF), covers 60-80% of the soil surface. Rhus burchellii and Prolasparagus suaveolens (species group This variant lacks exclusive diagnostic species. Acacia karroa AJ) are conspicuous. Themeda triandra (species group AJ) is the and Sehinus molle. which differentiate the Acacia karroo- Schi only abundant grass species (Table I). nus molle Variant, are absent in this variant (Table I). Rhus {an This variant recorded an average of 13 species/reieve (Table 1). cea (species group H) has a wide distribution and generally exceeds 2 metres in height. Olea europaea (species group K) and 1.1.3.5 Rhus lancea-Diospyros lycioides Variant Rhus /ancea (species group H) are the most common tree species The Rhus lancea- Diospyros Iycioides Variant occurs mainly on present. The shrubs, Budd/eja sa/igno (species group Q), Rhus the lower half of the south-facing slopes slightly above drainage erosa (species group AF) and R. /mrche/t;i (species group Al) channels. The soil is very shallow «50 mm deep) and rocky with are not widely dispersed but have high cover-abundances in cer gravel and stones from upslope covering the soil surface. No tain areas (Table I). Themeda Iriandra (species group Al) is the large dolerite boulders are visible on the soil surface. most important grass encountered. Diagnostic species are absent (Table t). The constant presence An average of9 species/releve were recorded for the Rhus lon of Rhus lancea (species group H) is the most conspicuous differ eea- Olea europaea Variant (Table I). ence between this variant and the other sub-divisions of the 1.1.4.3 Osyris lanceo/ala- Rhus lancea Variant Diospyros lycioides-Buddleja sa/igna Sub-community (Table The Osyris lanceo/ala- Rhus lancea Variant is restricted to I). Buddleja saligna (species group Q), Olea europaea (species ravines of south facing footslopes. The habitat is more moist than group K), Diospyros /ycioides (species group F) and Rhus lancea that of the previous two variants of the Rhus lancea- BlIdd/eja (species group H) have high constancies with D. lycioides and R. saligna Sub-community. Large dolerite boulders are common /ancea less abundant (Table I). Shrubs are scarce with Rhus and provide perfect hiding places for the rock hyrax (Procavia erosa (species group AF) and R. burchellii (species group AJ) capensis). The soil surface is trampled due to continuous over being the most common species present (Table 1). grazing by livestock. This variant recorded an average of 12 species/reieve (Table 1). This variant lacks exclusive diagnostic species, but the pres 1.1.4 Rhus lancea- Buddleja sa/igna Sub-community ence of Osyris lanceolala differentiates it from the previous two variants of the Rhus lancea- Budd/eja saligna Sub-community This sub-community is encountered on gentle (5°_20°) (Table I). According to the Tree Society of southern Africa south-facing slopes and in drainage channels with shallow soils (1969), 0. lonceolata is found growing on rocky ridges, outcrops « 150 mm deep). The soil is less rocky than in the Diospyros and hillsides amongst other species and is never found in abun Iycioides-Buddleja sa/igna Sub-community. Fine gravel covers dance in the Witwatersrand. This was also the case here. Rhus the soil surface. laneea (species group H) and Olea europaea (species group K) Diagnostic species are absent, but the absence of Diospyros are the only other regularly occurring tree species present. Blld Iycioides (species group F) in particular and the higher dleja sa/igna (species group Q) and Rhus erosa (species group cover-abundance of Rhus lancea (species group H) are notewor AF) are the most prominent shrubs. Grasses are scarce with EIi thy (Table I). onurus muticlts (species group AF), Themeda lriandra and Het The Rhus lancea- Budd/eja sa/igna Sub-community comprises eropogon contor/us (species group Al) being most common three distinct variants (Table 1). (Table 1). An average of 14 species per sample plot were recorded for 1.1.4.1 Acacia karroo-Schinus molle Variant this variant (Table I). The Acacia karrocrSehinus molle Variant is associated with the footslopes of south-facing slopes in drainage channels. The soil 1.1.5 Osyris lanceolala-Olea el/ropaea Sub-community is generally clayey and covered by a thick layer (100- 150 mm This plant community is encountered on the steeper (25°_50°) thick) of gravel and stones. south-facing slopes. The soil is generally rocky and shallow « 100 s. Afr. 1. 130t. 1998. 64( 1) 11 111111 deep). Rock sheets are frequently found and the average rock generally shallow « 100 mm deep) with large dolerite boulders cover is 30- 50%. and rock sheets comm only occurring. The Opunliaficils-inciica This sub- communilY has no diagnostic species but is charac Buddleja saligna Sub- community is virtually completely terised by the presence of Osyris lanceo/ata (species group I) in exposed to direct sunlight and wind, with the trees generally not the absence of Rhus lancea (species group H). Olea europaea exceeding 2 m in height. (species group K) and Osyris lanceo/ala (species group I) are the The exotic Opllntiafic fls-indica (species group K), introduced most abundant tree species with the shrubs Buddleja saligna from the U.S.A. (Coates Palgrave 1984) have become natural (species group Q), Euclea crispo, Rhus erma (species group ised and are now widespread and extremely troubl esome in cer AF), 11. hll/"chellii and 11. ciliata (species group AJ) also being tain areas. The high cover-abun dance values for Bliddleja conspicuoll s. Themeda triandra and Heteropogon contorills sa/igna (species group Q) are characteristic. (species group A J) are the most abundanl grasses. These shrubs are small « 2 111 high ), but numerous. Euclea An average of 13 species per sample plOl were recorded for crispa (s pecies group AF) is the onl y other noteworthy tree spe this sub-community (Table I). cies present. The grass, The meda Irialldra (species group Al), dominates the lower stratum with Felicia/ilifolia (species group 1.1.6 Zi=iphus /1lllcronata- Olea europaea Sub-community AF) and Rhus cilia/a (species group Al) being the most promi Thi s sub-community is found on the steep (15°-50°), boul nent representatives of tile shrub stratum (Table 1). der-rich sOllth facing slopes of hills. The soil surface is uneven An average of7 species per sample plot were recorded for this and rocky. sub-community (Table I). The hi gh constancy of Ziziphlls mllcronala (species group J) and Olea I.!uropaea (species group K), as well as the concen 1.2.2 Hermannia bIJloniifolia-Pavonia. bllrchellii trated occurrence of the exotic COLOneaster sp. (species group J), Sub-community differentiate this sub-community from the Osyris lanceolara This infrequent sub-community occurs in shady spots on the Olea europaea Sub-col11munity (Table I). According to Coates north-faci ng foots lopes of hills. Large, round boulders virtually Palgrave ( 1984). Z m1fcronata occurs in a wide variety of habi cover the soil surface. The tree stratum is generally not higher tats, varying from open woodland to all uvial soil s along rivers. It than 2 metres. The vegetation is overgrazed by livestock and the is also said to indicate the presence of underground water exposed soil surface is trampled. (Coates Palgrave 1984). The differentiating species listed in species group L (Table 1) Olea ellropaea (species group K) and Buddleja saligna (spe mainly occur in the shade of dolerite boulders, with Hermannia cies group Q) are conspicuous with Euclea crispa, Feliciajilifo bryoniifolia and Pavonia bllrchellii (species group L) being the lia (species group AF), Rhus bl/rehel/ii, R. ciliala and most abundant (Table I). It furt her differs from the Opuntia Pro/asparagus laricinlls (species group Al) being the most abun ficus-indica- Buddleja sa/igna Sub-community in the absence of dant shrubs. Grass species are scarce with Themeda triandl'a Opuntiajicl/s-indica (species group K). Senecio consanguineus (species group AJ) being the most common (Table 1). and Me/ianthus comosus are exclusive to this sub-community The Zizjphus mucronatQ- O/ea europaea Sub-community where Buddleja saligna (species group Q) is rather inconspicu recorded an average of 13 species per sample plot (Table I). ous (Table I). The locally dominant Rhus ciliata (species group Al) is the onl y shrub worth mentioning and Themeda triandra 1.1.7 Olea f! uropaea- Bl/dd/eja saligna Sub-community and Aristida conges/a (species group AJ) are the only abundant This shrubland sub-community occurs randomly on hills and grasses (Table I). ridges in the study area. The aspects are generally south, An average of 8 species/releve were recorded for this south-west and east. The soi l is rocky and shallow « 100 mm sub-community (Table I). deep). Characteristic of this widely distributed sub-community is the 1.2.3 Maytenlls polyacantha- Buddleja sa/igna Sub-community absence of diagnostic species and the complete dominance of This vegetation represents an open scrub and occurs mainly on Olea ellropaea (species group K) and Buddleja saligna (species and around the crests of rocky hills. Overgrazing is a common group Q}. This vegetation unit also lacks species of species phenomenon and damage to the vegetation, particularly by the groups A to J (Table I). This is an open shrub land with few other rock hyrax is evident. Maytenlls polyacantha (species group M) woody species occurrin g. Tarchonanlhus camphoratus (species is often heavily utilized. group Z), Euclea crispa, as well as the shrubs Rhus erosa, Ehre The most conspicuous woody species is BlIddleja saligna lia rigida, Felic.:ia fi/frolia (species group AF), Rhus burchellii (species group 0) which has a high cover-abundance (Table 1). and R. ciliata (species group Al) are also prominent. The grass, In the absence of species from species group 0, Mayfenus polya Themeda triandra (species group Al), has a restricted dominance cantha (species group M) is diagnostic of the Maytenlfs polya (Table I). cantha- Bliddleja saligna Sub-community. Rhus burchellii The Olell europaea- BlIddleja saligna Sub-community (species group Al ) and to a lesser extent Diospyros Iycioides recorded an average of 10 species per sample plot (Table I). (species group F) are the only other prominent woody species, with Themeda triandra (species group Al) the only dominant 1.2 Budd/e. ja saligna- Ellclea crispa Community grass (Table 1). Euclea crispa and Diospyros austro-africana This plant community occurs on the drier north- and west-facing (species group AF) occur locally (Table I ). footslopes and crests of hills and ridges. Overgrazing is a more An average of 10 species/releve were recorded for this common phenomenon than in the Olea europaea- Buddleja sub-community (Table I). saligna Community. In contrast to the Olea eUl'opaea-Buddleja 1.2.4 Pupalia lappacea-Lantana rugosa S ub ~community saligna Community, Olea el/ropaea (species group K) is virtu ally absent fr om this vegetation unit (Table 1). This sub-community mainly occurs on west-facing slopes oflow Seven di sti nct vegetation units were distinguished (Table I). hills in the shade of trees. Generally the soil surface is rocky and covered with fine gravel. 1.2.1 Opuntia/icils-indica- Buddleja saligna Sub-community The Plipalia lappacea- Lalllana rugosa Sub-community is This sub-community is restricted to the crests of hills. The soi l is characterised by Grell'ia occidentalis (species group K) in the 12 S. Afr. l. Bot. 1998. 64( I) presence of the differentiating Pupalia /appacea, Lantana of the hills and ridges. The gradient varies from 10-20°, with a rugosa, Solanum relrqf!exam, Chenopodium ambrosioides. C. rock cover of 20-70%. Large sandstone boulders are a common album. Sc.: hkllhria pinnafQ, Hibiscus lrioflUnl, the grass Setaria phenomenon, especially at the edges of the overhanging cl iffs. l'erlicillata and COli/me/ina benghalensis (species group N). This sub-community lacks diagnostic species and most of the These forbs afe in dicating continuous habitat disturbance. Bud species in species groups A to P (Table 1). The only exceptions d/eja saligno (species group Q), Grewia occidentalis (species are the scanty occurrences of Solanllm coccineu1J1 (species group group K) nnd Rhus burchellii (species group AJ) aTe the most E), Pavonia burchellii (species group L) and Hibiscus trioJ1l1m common and widely distributed woody species. Among the (species group N, Table I). grasses Eustachys paspa{oides (species group T) and Sporobollls A shrub stratum is well developed with the woody species .fimbria/lls (species group AF) are abundant. Themeda triandra Buddleja saligna (species group Q), Euclea crispa (species (species group AJ) is conspicuously absent. The small fern, Pe/ group AF), Rhus burchellii (species group Al) and 10 a lesser toea calome/anos (species group Al) occurs, with a high con extent Rhus erosa (species group AF) being dominant. The small stancy. in the crevices between rocks. sh rub, Rhus ciliala (species group Al), is also abundant, espe All average of 18 species/reJeve were recorded for this cially in the sheltered and moist environment provided by the sub-community (Table I). boulders. The hardy Prolasparagus SlriatllS (species group AF) is locally common to abundant. Grasses are scarce with only 1.2.5 Aloe broomii- Themeda Iriandra Sub-community Themeda triandra (species group Al) and Sporobolus fimbriatus The Aloe bl'oomii- Themeda Iriandra Sub-community occurs on (spec ies group AF) being conspicuous (Table I). north easterl y-facing slopes and ravines with gradients varying An average of 8 spec ies/releve were recorded for this from 8°_25 °. Large dolerite boulders and rock sheets are abun sub-community (Table I). dant. In the lower-l yi ng areas, weathered sandstone and gravel are common. The soil surface is disturbed by trampling of live 1.3 Tarchonanthus camphoratus- Themeda Iriandra stock. Community A/oe broomii. commonly known as 'Bergaahvyn' or 'Slao This plant community occurs on dry, over-utliized crests and pla gaalwyn'. Indig~fera sessilifolia and Nenax microphylla (species teaux of hills and ridges. Isolated patches of this shrub land occur group 0) differenliate this sub-community (Table I). According on dry, disturbed, westerly or northerly-facing slopes. Generally to Jeppe (1974), A. broomii got its native name 'Slangaalwyn' the habitat is less rocky than in the Olea europaea-Buddleja because of the developing racemes resembling a cobra-like saligna and Buddleja saligna- Euclea crispo Community. This snake. A. broomii is found from Prieska in the Northern Cape to shrubland is primarily characterised by the regular occurrence of Luckhoff in the western Free State where it grows well in soi l Tarchonanthus camphoratlls (species group Z), a species that is with a high lime content and flourishes best in low rainfall areas dominant over large areas of the scrub veld of the western Free with frost in winter (Bornman & Hardy 1971). Woody species State (Venter & Joubert 1985). are scarce with only Maylenus polyacanlha (species group M), In contrast to the shallow « 100 mm deep) soils of the Olea Buddleja saligna (species group Q), Euclea crispa and Rhlls europaea--Buddleja saligna and Buddleja saligna- Ellclea crispo erosa (species group AF) common. Themeda Iriandra (species Communities, the soils associated with this community are often group All is the on ly prominent grass species with Digilaria er; deep (> 300 mm deep). Duplex soils with B-horizons are promi anrha (species group U). Sporobolus fimbrialus, Cymbopogon nent on the slopes (Land Type Survey Staff, in press) while cal plurinodis, Eragroslis curvula (species group AF) and Heleropo careous soils occur in the low-lying areas and plains. gon CO flforlllS (species group AJ) less abundant. The forb, Four distinct sub-communiti es further characterize this plant Stachys rugosa (species group Al), is commonly found growing community (Table I). in the crevices between the dolerite rocks. 1.3.1 Digitaria eriantha- Tarchonanthlls camphora/us The A/oe broomii- Themeda triandra Sub-community recorded an average of 16 species per sample plot (Table I). Sub-community This plant community is present on the plateaux of hills. Large 1.2.6 Triraphis andropogonoides-Budd/eja sa/igna dolerite boulders occur in this community resulting in microhab Sub-community itats with a moister environment than surrounding areas. The soil This sub-community is encountered on north-facing slopes of varies from rocky to sandy especially in the lower-lying areas. less than 10° and ravines where the soil is well-drained and 60- In the presence of Tarchonanthus camphoratlls, the occur 70% of the surface is covered by rock sheets. No large boulders rence of the grass, Digilaria erianllIa (species group U), differ occur. entiates this sub-community (Table 1). Under normal The constant occurrence of the grass, Triraphis andropogo circumstances this grass is regarded as indicative of good pasture noides (species group P) differentiates this sub-community (Van Oudtshoorn 1991). Other abundant grasses include Arislida (Tabl e I). According to Van Oudtshoorn (1991), T. andropogo diffusa. Sporobolusfimbrialus. Cymbopogon plurinodis (species naides is unpalatable and commonly occurs in open grasslands group AF) and Themeda 'riandra (species group Al). Woody on rocky hills. Buddleja saligna (species group Q), Euclea crispa species are limited and restricted to the trees Tarchonanlhus (species group AF) and Rhus burchellii (species group AI) are camphoratus (species group Z), Euclea crispa and the shrubs the most important woody species present with R. ciliala (spe Rhlls erosa (species group AF) and Rhus burchellii (species cies group AJ) being the most locally abundant shrub, particu group Al), with Felicia fllifolia (species group AF) being less larly at the footslopes. The only other commonly occurring abundant. The fern, Cheilanlhes eckloniana (species group AF), graminoids are Themedo Iriandra, Heteropogon contortus and is also abundant, especially in micro-habitats between large Eragroslis lehmanlliana (species group AJ, Table 1). boulders. The Tr;raphis andrapogonoides- Buddleja saligna Sub-commu Three distinct variants further characterize this sub-commu nity recorded an average of 8 species per sample plot (Table I). nily (Table I). 1.2.7 Buddleja saligna- Themeda Iriandra Sub-community 1.3.1 .1 Hermannia vestUa- PrOlasparagus capensis Variant This widely distributed sub-community occurs mainly on the The habitat in which this limited variant occurs is generally dry middle and upper half of the northerly and westerly-facing slopes and about 60% of the surface area is covered by large, roundish S. Afr. J. Bot. 1998, 64( I) 13 and sub-angular stones and rocks between 0.1 and 0.5 m in diam rock plates covering 60- 70% of the soil surface. eter. Rock sheets are also found. EWJ10ps ml/llifidl/s (species group W) differentiates this Although not diagnostic, this variant is characterised by the sub-community (Table 1) and only a few other species occur. scanty occurences of liermannia vesti/o and Protasparagus cap The tree Euclea crispo (species group AF) and the small shrub ensis (species group R), Trees are scarce and are restricted to Rhus ciliata are the most important woody species. Grasses are Tarchonanthus camphoratus (species group Z) and Euclea virtually restri cted to Themeda Iriondra (species group Al) and cri.\pa (species group AF). Shrubs present incl ude Rhus bllrchel Arislida diffusa (species group AF, Table I). Themeda t";andra Iii (species group AJ) and the dwarf shrub Felicia filifolia (spe has a restricted dominance, but is notably less abundant in this cies group AF). The only conspicuous graminoids are Themeda subcommunity than in the Helichrysum =eyheri- Themeda triwl t";andra and Heleropogol1 contorlllS (species group Al). dra Sub-community (Table I). An average of 17 species/releve were recorded fOT this variant The Euryops mult!fidus- Tarchonanthus camphoratus (Table I). Sub-community recorded 7 species per sample plot (Table I). 1.3.1.2 Selago albido- Oxolis corniculata Variant 1.3.4 Rhigoztfl1l obOl'Ollflll-Tarc..:liOlwnlhlls camphOralllS Sub-community This variant is associated with lowlands and less rocky soil than that of the Hermmmia veslila- Pro/(lsparaglls capensis Variant. This sub-communi ty mainly occu rs on the dry overgrazed and Sandy soils are more common. often trampled crests of north-facing slopes The soi l surface is The differentiating species of this vegetation unit (species rocky and covered with large boulders. group S, Table I) have low cover-abundance values and are The diagnostic shrub, Rhigo=ul11 obovowm (generally not inconspicuous. The slightly higher cover-abundance values of higher than 2 m) (species group V), is the most conspi cuous Digitaria eriantha (species group U), Aristida diffusa. Rhus shrub and often completely dominates the vegetation. The tree, erosa. Sporobolus fimbrialus, Cymbopogon plurinodis, the Tarchonalllhlls camphorat/ls (species group Z). is the only other absence of Heleropogol1 conlortus and Stachys rugosa (species abundant woody species present (Table 1). Thi s sub-community group AJ), as well as the dominance of Euclea crispo (species is inconspicuous due to contin uo lls overgrazing and the occur group A F), characteri ze this variant (Table I). The presence of rence of only a few species (Table I ). Noteworthy is the absence [he grass, Aristida congesla and the Karoo encroacher, Chryso of species in species group AF with the scanty occu rrence of coma ciliata (species group A l), also differentiate this commu Ehrelia rigida being the on ly excepti on (Table 1). nity from the He rlJlannia veslila-Prolasparaglls copens;s Two variants further divide this sub-community (Table 1). Vari an t (Table 1). Wah~rrida saxatilis often grows in association 1.3.4.1 Slipagrostis namaqllellsis- Rhigozul11 obovatum Variant with C'h'J'soCOIl1a ciliata on sandy soils. An average of 18 species/releve were recorded for this variant This variant occurs on trampled ground, covered with a thick (Table I). (100 mm thick) layer of sand on north-facing slopes. Gravel and 1.3.1.3 Ligh(footia albelJs- Euslachys paspaloides Variant stones (50 mm or less in diameter) cover 50% of the soi l surface. The grass, Slipagroslis namaquensis and th e forb, Berkheya This variant occurs mainly on rocky, sandy soil wi th fine gravel pinnalijida (species group X) are diagnostic of this variant, but com mon 011 the soil surface. This variant lacks exclusively diagnostic species and is incon th e dominant Rhigo=w7I obovatl/111 (species group Y) is more spicuous. Except Tarchollonthlls campl1oratlls, oth er woody spe conspicuous. According to Coates Palgrave (1984). R. obovalum cies include Euclea crispa, RIms erosa, Felicia filifolia (species commonly occurs in dry rocky places and karroid scrub. R obo group AF) and Rhus bllrchellii (species group AJ). The fern , vallfnl is often heavil y browsed on by game and stock so that Cheilanlhes eckloniana (species group AF) has a higher plants are frequently kept down to a height of about I 111 (Coates cover-abundance here th an in the Selago albida-Oxolis cornicll Palgrave 1984). This was also the case here with the average lata Variant (Table I). Abundant grasses are restricted to height of R. obOVafllnl not exceeding 1 m. Kleinia longtfolia Themeda l";andra and He leropogon conlorllls (species group (species group AD) has a low cover-abundance in this variant. Al). but is absent from the Rhigozl/l/1 ObOl'a fum - Heteropogon contor The Ligh(foOlia albells- Eustachys paspaloides Variant Ius Variant (Table I ) . 27 recorded an average of 16 species/releve (Table I ). The Slipagrostis lIamaquens;s-Rhigo=lfIn obovatul11 Variant recorded an average of7 species/releve (Table I ). 1.3.2 Heliclllyslll11 zeyheri- Themeda Iriandra Sub-community The Helich,yswlJ =eyheri- Th emeda /riandra Sub-community is 1.3.4.2 Rhigozum obovalum- Heleropogon contortus Variant present on the overutil ized crests higher up on the north-facing This variant occurs under virtual ly the same habitat conditions as slopes of hills. No boul ders occur, but the soil is rocky and shal the Stipagroslis namaquensis-Rhigo=lIIl1 obovatum Variant. Ter low ( < 100 mm deep). mite heaps are conspicuous all the soi l surface. The vegetation is The differentiating species are listed in species group V, all of overgrazed and the soil surface is trampled. The vegetation, whi ch have a low cover-abundance (Table 1). The tree, Tarcho especially Rhigozul11 obovall1l11. is lllu ch smaller (not higher than nanthus camphorallis (species group Z), is conspicuous. cam r 1 m) than in th e Stipagroslis lIamnquellsis- RhigozulII obovawl1I phoratus is shrublike. generally not exceeding 2 m in height. A Variant. RhigoZlIl1I obOWJllIl11 also has a lower cover-abundance further characteristic of this vegetation uni t is the dominance of than in th e Stipagrostis nomaqllensis- Rhigo=lIm obo\'OIl1m Vari Themeda lriandra (species group Al). Heteropogon con/orllls (species group Al) is also abundant and is often characteristic of ant (Table I). This variant lacks exclusive diagnostic species but is charac rocky habitats (Van Oudtshoorn 1991). The Helichrysllm zeyheri- Themeda triandra Sub-community terised by the presence of Heleropogon contortllS (species group recorded 14 species per sample plot (Table 1). Al) which'is absent in the Slipagroslls namaquensis- Rhigozum obovalum Variant (Table I ). Also conspicuous is the absence of 1,3.3 Euryops multffidlls- Tarchonanthus camphoratus Stipagroslis namaqlle1lSis an d Berkheya pinnatif/da (species Sub-community group X), diagnostic of th e Slipagrosiis namaquellsis- Rhigozul11 Thi s sub-community is limited to the plateaux of hills with large obovalllln Variant (Table 1). 14 s. Atr. l. Bot. 1998, 64( 1) 1.4 Euclea crispa- Themeda triandra Community with the Setaria sphacelata-Rhus ciliata Sub-community, Euclea crispa and Rhus cilia/a are also abundant, but Themeda fl'iandra This plant community occurs on west, north and north-west fac (species group AJ) is less conspicuous (Table I). E. crispa (species ing slopes of low hills in the central parts of the study area. The group AF) often fonns dense stands. Besides T. /r;andra, other vegetation is often severely overutilized by livestock and the her grasses such as Arislida diffi{sa, Sporobolus fimbriatus and Elionu baceoLis layer is often limited or even completely destroyed. The rus nluficus (species group AF) are also present, but are inconspic slopes are mostly dry and warm due to the high solar radiation uous (Table I). associated with northerly facing slopes (ROSSQllW 1983). Surface An average of 12 species/releve were recorded for this rocks are predominantly doleritic with layers of sandstone (often sub-community (Table I). deeper than 150 mm) a common phenomenon on the footslopes. This community lacks exclusive diagnostic species. Euclea 1.4.4 Kleinia longifolia-Themeda Iriandra Sub-community crispa is the only woody species present with high cover-abun The distribution of this sub-community is restricted to the lower dance values (species group AF, Table I). The small shrub, Rhus half of the north and west-facing rocky slopes. The soil surface is ciliata (species group AJ), with a random distribution has a severely trampled and overgrazing is common. The soil is sandy restricted dominance especially in the more rocky habitats. and deep ( > 300 111m deep). Themeda triandra, Heteropogon contortus (species group AJ) This sub-community lacks exclusive diagnostic species but is and Adstida diffitsa (species group AF) are the grasses most rather characterised by the marginally greater frequency of often encountered. Sporobolus jimbriatus and Elionurlls J1l11ticllS Kleinia longifolia (species group AD) than in the Phy//anlhus and the small fern Cheilanthes eckloniana (species group AF) parvulus-SesamuJ1l capense Subcommunity. Although K. /ongi have limited occurrences (Table 1). folia is regarded as highly unpalatable, it is often utilized by live This community is further divided into six distinct sub-com stock, especially during the winter months (Vahrmeijer 1981). munities (Table I). According to Vahrmeijer (1981) this species is extremely toxic, 1.4.1 Euclea crispa- Tragus berteronianus Sub-community especially to horses and cattle. Other abundant species present include Euclea crispa (species group AF), Themeda triandra, This sub-community is encountered on the dry north-facing Rhus ciliata and Prolasparagus laricinllS (species group Al, slopes of dolerite hills. The soil is rocky with stones covering Table I ) . 20--40% of the soil surface. The Kleinia longifolia-Themeda Iriandra Sub-community The small grass, Tragus berteronianus (species group AA), recorded an average of only 8 species/releve (Table 1). differentiates this sub-community, with the < 2 m high 'shrubby' tree, Euclea crispa (species group AF) being the most abundant 1.4.5 Cymbopogon excavatus- Euclea crispa Sub-community woody species. According to Van Oudtshoorn (1991), T. berle The Cymbopogon excal'a/us- Euc/ea crispa Sub-community is ronianus is unpalatable to livestock and it is an indicator of encountered on-the upper half of the westerly-facing slopes. The degrading veld conditions. Euclea crispa (species group AF) is habitat is more rocky than in the Phyllanthus parvulus-Sesamum the most important woody species present. Themeda triandra capense and Kleinia longifolia-Themcda triandra Sub-commu and Heteropogon contortus (species group AJ) are the only com nities. Large boulders are common, but no gravel is visible on the monly encountered grasses. The dwarf fern, Cheilanthes eckloni soil surface. ana (species group AF), has a patchy occurrence and is mostly The grass Cymbopogon excavatus (species group AK), is the restricted to crevices between rocks. only differentiating species (Table I), The higher cover-abun The Euclea crispa-Tragus berteronianus Sub-community dance values of the grass, Aristida dijjilsa (species group AF), in recorded an average of 10 species/rei eve (Table I). this sub-community are also noteworthy (Table 1). Other grasses 1.4.2 Setaria sphacelata-Rhlls ciliata Sub-community present include Sporobolm fImbria/lIS (species group AF), Themeda /riandra and Heteropogon contor/us (species group The Setaria ~phacelafa-Rhus ciliata Sub-community is also Al). Euclea crispa (species group AF) is the most important tree associated with north-facing slopes, but the habitat is cooler and encountered. The most important shrubs include Rhus burchellii standing water in the low lying areas occurs for virtually weeks and R. ciliala (species group Al) with the dwarf shrub, after good rains. The soil is less rocky with the clay content gen Protasparagus striatus (species group AF), having a restricted erally exceeding 40% (Land Type Survey Staff, In press). dominance (species group AF, Table I J. Setaria sphacelata (species group AB) differentiates this veg An average of 10 species/releve were recorded for this etation unit. The absence of the small fern, Cheilanthes eckloni sub-community (Table I). ana, mentioned in the Euclea crispa-Tragus berteronianus Sub-community, the lower cover-abundance of Heteropogon 1.4.6 Euclea crispa-Aris/ida difJusa SUb-community contortliS (species group AJ) as well as the presence of the dwarf The Euclea crispa-Arislida d~ffusa Sub-community is found on shrub, Rhus ciliata (species group AJ), further differentiate this clearly disturbed (a1 least in patches), dry north-west facing community. Themeda triandra (species group AJ) is the only slopes. other noteworthy grass (Table I). This sub-community lacks diagnostic species as well as spe An average of 9 species/releve were recorded for this cies which were encountered in all the sub-communities of the sub-community (Table I). Euclea crispa-Themeda /riandra Community. This is mainly a shrubby-grassland community with Euclea cri~pa (species group 1.4.3 Phyllanlhus parvulus-Sesamum capense Sub-community AF) being the only important tree and Rhus ciliala (species The habitat conditions for this limited sub-community are virtu group Al) being the only abundant shrub. Among the grasses, ally the same as for the Setaria sphacelata-Rhus ciliata Aristida diffusa (species group AF), Themeda triandra and He/ Sub-community. The soil surface is covered with gravel and thus eropogon conlortus (species group AJ) are abundant. Other grass appears to have a more rocky surface. species present include Sporobolus .fimbria/us and Enneapogon Setaria sphacelata is absent from this plant community (Table 1) scoparius (species group AF, Table 1). and the differentiating species are listed in species group AC (Table An average of 9 species/releve were recorded for this I), all of which have a low cover-abundance value (Table I). As sub-community (Table I). S. Afl'. J. Bot. 1998,64(1) 15 600 c 500 ...... , ... 400 . ; .. ' ...... / ...... a c N • 300 ...... , ...... , ...... x • :d « · a a a · b. . a a · i. ' b : d .. l'a' .:If. ~ II b c 200 ...... ~.P~M .. ~tP't ·c ~.;..:..:c.:""-h>P--' ...... ,.. . R . t) If · 8 bd a a ab~ a b $ b b a 100 a~ o . : ...... , .... ' ...... ; ...... : . . .. . , ...... ~. o 100 200 300 400 500 600 Axig 1 FootalopBB Ravine. Crests Plateaux Figure 2 A DCA ordination of the releves of the rocky outcrops of the southern Free Statl! . a: Olea tfllropaea- Ruddleja saligna Community b: Budd/ejo .'!aligna- Ellc/ea crispo Community c: Tarcllonanthlls ClImphoraluS- rhemeda lriandra Commun ity d: EUc/(!lI crispa- Themeda Jri(lndra Commun ity c: Eherlmt=ia spinosa- Mohria r.:ajjrorllnl Community f: Felicialllw'icafa- Mohria caffrorllnl Community 2 Mohria cafJi'orum- Themeda triandra Major-community The thorny succulent, Eberlan:ia spinosa (species grou p AG), is the only differentiating species for this sub-community but the This major-community is predominantly associated with the flat fern, Mohria ca/frorlfm (species group AI), completely domi areas on the ridges and hill plateaux. The habitat is generally dry nates the vegetation. Other species with a limited distribution are and virtually unprotected from wi nd. The soil is shallow 100 « the shrub, Rhigazllm obovalum (species group V), the grass, Het % mill deep) and rock slabs cover 60- 80 of the soil surface. The eropogon cantor1us and the Karoo encroacher, Chrysocoma cili soil has a sandy-gravelly texture with dolerite stones visible on ata (species group AJ , Table I). the surface, The Mohria (,.'{!Ifrorum- Themeda lriandra Major-community 2.2 Felicia Inllricata- A4ohria ca.lJrorll111 Community is differentiated by the small fern , Mohr/a cq{fl'orufII (species The Felicia muricata- Mohria caffrof'llln Community is group AI, Table I). It is also differentiated by the limited occur restricted to the more disturbed areas th e crests of hills and on rence of large trees and shrubs. plateaux. The soil is less rocky than for the Eberlanzia spinosa Th is community divides into two di stinct units (Table 1). Mohria caffrorum Community and is often sandy. Fine gravel 2.1 Eberlan=ia spillosa-l\1ohria caffronun Community covers the soi l surface. Felicia muricata (species group AH) differentiates this com This plant community is encountered on the dry plateaux of munity. Mohria cqffrorul11 (species group AI) is also common, rocky hills and ridges, which often show signs of degradation but far less dominant than in the £ber/anzia spinosa- Mohria caf due to continuous over utilization by li vestock, The soil is very frorum Community, while the grass, Themeda Iriandra. is more shallow (often < 50 mm deep) and rocky. Rock slabs cover 70- abundant within this community (Table I) . Rhus ciliala (species 80 % of the soil surface and exposed soil is limited. group AJ) is locally dominant Clnd the grass Arislida congesta 16 S. Arr. J. Bot. 1998,64(1) (species group AJ) is further indicative of the disturbed condition References of this community. ARNOLD, T.H. & DE WET, B.C. 1993. Plants of southern Africa: names and distribution. Mem. bOI. Surv S. Aji-. 62: 1-825. Ordination BORNMAN. H. & HARDY. D. 1971. Aloes of the South African veld. A DCA ordination of the releves is given in figure 2. The two Voortrekker Press. Johannesburg. major communities described here have noteworthy similarities BREDENKAMP, G.1" JOUBERT. A.F. & BEZUIDENHOUr. H. rmd differences. The Eherlanzia spinosa- Mohria caffrorum and 1989. A reconnaissance survey of the vegetation of the plains in the Felicia muricata- Mohha caffrorum Community of the Mohria Potchefstroom- Fochville-Parys area. S. Afr. 1. BOL 55 (2): 199-206. c(?I}i'orllm-Themeda triandra Major community (indicated by e CARR, J.D. 1976. The South Atrican Acacias. Conservation press (PTY.) LTD. Johannesburg. and f respectively in the scatter diagram) are virtually restricted COATES PALGRA VE, K. 1984. Trees of Southern Africa. 2nd Revised to the high-lying areas on crests and plateaux while the Euclea edn. Struik Publishers. crispa-ArisJida diflilsa Major Community is restricted to the COETZEE, J.P., BREDENKAMP, G.1. & VAN ROOYEN, N. 1993. footslopes of hills, ravines and crests (Axis 1, Figure 2), No clear The Sub-humid Warm Temperate Mountain Bushveld plant commu discontinuity is associated with axis 2 of the diagram (Figure 2). nities of the Pretoria- Witbank- Heidelberg area. S. Afr. J Bot. 59(6): 623-632. Discussion DU PREEZ, P.1. 1991. A syntaxol1ornical and synecological study of the The two major plant communities were all restricted to specific vegetation of the south-castern Orange Free State and related areas areas within the study area. In most cases, the ordination illus with special reference to Korannabcrg. Ph.D. dissertation, University trates the similarities between the plant communities described. of the Orange Free State. Bloemfontein. The vegetation of the rocky outcrops is in a state of continuous ECKHARDT, H.C. 1993. A synecological study of the vegetation of the degradation because of relatively low rainfall for the last number north-eastern Orange Free State. Unpublished M.Sc. thesis. Univer sity of Pre loria, Pretoria. of years, as well as the continuous overutilization by livestock. FULS, E.R., BREDENKAMP, G.J. & VAN ROOYEN, N. 1993. Low This is in contrast to the findings of Stuart-Hill e/ al. (1984) in thicket communities of rocky outcrops in the northern Orange Free the climatic climax Grassland Biome where a strong presence of State. S. Afr. J. BOI. 59 (4): 360-369. woody species on the rocky outcrops was recorded. According to FULS, E.R. 1993. Vegetation ecology of the northern Orange Free State. Stuart-Hill e/ al. (1984) and Fuls (1993) the strong presence of Unpublished Ph.D. dissertation. University of Pretoria, Pretoria. woody species is ascribed to favourable moisture regimes associ HILL, M.O. 1979a. TWINSPAN - a FORTRAN program arranging ated with high percentages of surface rocks and rocks in the soil multivariate data in an ordered two-way table by classification of indi profile. Rainfall accumulation between rocks, concomitant with viduals and attributes. Cornell University. Ithaca, New York. the volume of the soil profile occupied by subsurface rocks, HILL, M.O. 1979b. DECORANA - a FORTRAN program for detrended results in deeper rainfall infiltration, favouring species with a correspondence analysis and reciprocal averaging. Department of Ecology and Systematics, Cornell University. Hhaca, New York. taproot system (Furs e/ al. 1993). JEPPE, B. 1974. South African Aloes. 2nd edn. Purnell & Sons. Cape The most important species associated with the rocky outcrops in Town. the southern Free State include the woody species Olea euro KOOlJ, M.S. 1990. A phytosociological survey orthe vegetation of the paea, BlIddleja saligna, Euclea crispa subsp. ovata, Rhus erosa, north-western Orange Free State. Unpublished M.Sc. thesis Univer Feliciafil{folia, Rhus burchellii, R. ciliata, Pl'otasparagus larici sity of Pretoria. Pretoria. nus, P. suaveolens as well as the grasses Themeda triandra and LAND TYPE SURVEY STAFF (IN PRESS). Land types of the maps Heleropogon contortus. Other woody species with restricted dis 2924 - Koffiefonteill and 2926 - Bloemfontein. Mem. agric. nat. tribution include Cllssonia paniculata, Diospyros lycioides, Rhus Resources S. Afr. No. 74. laneea, Osyris lanceolata and Tarchonanthus camphoratus. MACVICAR, C.N., LOXTON. R.F., LAMBRECHTS, J.J.N., LE Generally the south-facing slopes have a higher species diver ROUX, 1., DE V1LLlERS. J.M., VERSTER. E., MERRY sity than the north-facing slopes. This is in accordance with Du WEATHER, F.R., VAN ROOYEN. r.H. & HARMSE, H..I. VON M. Preez (1991), Eckhardt (1993), Kooij (1990), Malan (1992) and 1977. Grondklassifikasie, 'n Binomiese sisleem vir Suid-Afrika. Govt. Printer, Pretoria. Fuls (1993). This is because of the warmer micro-climate of the MALAN, P.W. 1992. Plantsosiologie van die Bloemfontein-wes distrik. northerly facing slopes (Rossouw 1983; Fuls 1993). According Unpublished M. Sc. thesis, University of the Orange Free State, B10- to Eckhardt (1993), aspect, topography and associated moisture emfonteitl. regime are the overriding factors controlling the distribution of MALAN, P.W., VENTER, H.1.T. & DU PREEZ. P.J. Vegetation ecol the thicket and woodland vegetation of the north-eastern Free ogy of the southern Free State: Plant communities of the Zastron State. This is also the case in the southern Free State as indicated Area. S. Afr. 1. Bot. (Submitted). in the ordination (Figure 2). MENTIS, M.T. & HUNTLEY, B.J. 1982. A description of the Grassland The restricted distribution of the majority of the plant commu Biorne Project. S. Afr. Nat. Scient. Frog. Rep. No. 62 pp. 29. nities associated with rocky outcrops, makes it imperative that MUELLER-DOMBOIS. D. & ELLENBERG, H. 1974 . Aims and Meth conservation of these plant communities receive high priority. ods of Vegetation Ecology. Wiley, New York. Future research will concentrate on the conservation status of ROSSOUW, L.F, 1983. 'n Ekologiese sludie van die boomgemeenska ppe van die Bloemfonteinomgewing, Oranje-Vrystaet. M.Sc. thesis, these species and the shrubland communities of the southern University of the Orange Free State. Free State. This delineation of the plant communities and associ SCHEEPERS, J.C. 1975. The plant ecology of the Kroonstad and Beth ated habitats of the rocky outcrops of the southern Free State lehem areas of the HighveJd Agricultural Region. D.Se. thesis, Uni should be used as the basis for future management and conserva versity of Pretoria, Pretoria. tion of these areas. The restricted distribution of the majority of SCHEEPERS, J.c. 1987. Grassland Biome Project: Proceedings of the the plant communities associated with rocky outcrops, together workshop on the classification and mapping. S. Afr. Ecosys. Frog. with the low species diversity, resulted from degradation, makes Dcc. Rep. Series 16: 1- 31. it imperative that these areas receive high conservation priority. STUART-HILL, G., TAINTON, G.c.. AUCAMP. A.l. & DANCK- S. Afr. J. Bot. 1998, 64( I) 17 WERTS. J.E. 1984. Intlltration and water use patterns in semi-arid VAN OUDTSHOORN. F.P. 199 1. Gids lot grasse van Suid-Afrika. South African Savanna. Proc 2nd Int Rang!. Congo Adelaide. Briza publications. Arcad ia. Pretoria. TREE SOCIETY OF SOUTHERN AFRICA . 1969. Trees and shrubs VENTER. H.J .T. & JOUBERT. A.M . 1910:5 . Kli mplantc. borne en of the Witwatersrand. Witwatersrand University Press. Johannes slruike van die Oranjc-Vryslcat. 2nu I!Jn .. PJ. lie Villicrs. Bloem burg. fontein. VA HR ME I1 ER. J. 1981. Gifplante van Suider-A frika \Va t veeverl iese WHITTAKER. R.H. 1978. Classitication or plant communities. W veroorsaak. Tahle Mountain Publi shers Ltd. Junk. The Hague.