Flora of the Kap River Reserve , Eastern Cape , South Africa

A detailed analysis ot the flora of the newly proclaimed Kap River Reserve (600 ha) is given. The reserve is adjacent to the Fish River and some 5 km from the Fish River Mouth It consists of a coastal plateau up to 100 m a.s.I. which is steeply dissected by the two rivers that partially form the boundary of the reserve. The flora of the reserve was sampled over a peri­ od o f three years and plants were collected in all the vegetation types of grassland, thicket and forest. 488 species were co l­ lected with a species to family ratio of 4:4. The majority of the taxa recorded represent the major phytochoria of the region. Nineteen species are endemic to the Eastern Cape, two are classed as vulnerable, five are rare, six are protected and a fur­ ther seventeen are of uncertain status. The flora of the Kap River has closest affinities to that o f the Alexandria Forest.


INTRODUCTION
The Kap River R eserve, ± 33° 30' S and 27° 9 ' E. is situated at the confluence o f the Kap and Fish Rivers along the east coast o f South A frica (Figure 1).The establishm ent o f the reserve is im portant, especially since only 3.04% o f the total area o f the Eastern Cape has been conserved (I.ubke e t al. 1986).Everard (1987) identified the thicket in the Fish River estuary as Tran sitional Subtropical T hicket, w hich Lubke et al. (1986) have given the highest priority listing for conservation in the Eastern Cape.It is the vegetation type with the largest proportion o f endem ics (30% ) and threatened plants ( 18%) and is considered to be vulnerable due to ch an g ing farm ing practices (Lubke et al. 1986).
The Eastern Cape coast with its mild subtropical climate is an area where four m ajor South African phytochoria (the Cape, K aroo-N am ib, A from ontane and Tongoland-Pondoland) converge to form a transition zone.The result ing com plexity o f the vegetation of the Eastern Cape is recognised by several authors (Goldblatt 1978;Werger 1978;Gibbs Russell & Robinson 1981;Cow ling 1983;W hite 1983;Lubke et al. 1986;Everard 1987;Acocks 1988;Palm er 1990).The Eastern Cape coast is also an area of transition with respect to climate, geology, soils and topography (Lubke et al. 1986).resulting in dramatic veg etation changes over short distances.Cowling (1983) has shown that the flora is transitional between that of the Cape and K waZulu-Natal, with elem ents of the Karoo. D yer (1937) and C om ins (1962) pioneered the study o f the coastal vegetation o f the eastern Cape region, but it is only in the last fifteen years that a m ore com plete picture of the diversity, phytogeography, ecology and conservation status o f both the flora and the vegetation has started to em erge (G ibbs Russell & Robinson 1981;C ow ling 1983;Lubke et al. 1986;Phillipson 1987;Everard 1987Everard . 1988;;Lubke et al. 1988;Phillipson & Russell 1988).
The Kap River Reserve (6 km 2 in extent) is located in the Bathurst D istrict in the w edge form ed betw een the Kap River and the Fish River estuary (Figure 2).The coastal plateau is about 100 m asl in this area and is steeply dissected by both river system s.The Fish River form s a large floodplain and the Kap River cuts across the plateau creating cliffs and steep slopes on its south bank and very steep, to steep, to m oderate slopes on the north bank.The Kap River is very slow -flow ing in this area, form ing large pools in the low er reaches and is not exposed to the saline influences o f the estuary.
The steep S-facing slopes are o f W itteberg quartzite and the cliffs are of the D w yka form ation.The plateau and the slopes tow ards the Fish River consist o f shales and m udstones o f the D w yka form ation (M ountain 1937).The soils o f the area are 'w eakly developed and interspersed w ith red sandy clay s' (H artm ann 1988).In the reserve the soils differ from place to place depending on the underlying geology.The floodplain o f the Fish River has very sandy soil, and the soils o f all the old cu l tivated lands are badly eroded.The coastal areas o f the Eastern Cape have a subtropical clim ate with tem p era tures ranging betw een 10°C and 22.2°C annually (K opke 1988).The annual rainfall is betw een 500 and 1 000 mm (Kopke 1988).A W alter-Leith diagram (Figure 3) su m m arises the data for the G reat Fish Point L ighthouse w eather station.

METHODS
Plants were collected from the various habitats (m esic and xeric thicket, grassland and riverine forest) and voucher specim ens with determ inavit labels are housed in the Selm ar Schonland H erbarium .G raham stow n (G R A ).A checklist was generated from the G RA d ata base.and records from the PRECIS database (P reto ria H erbarium C om puterised Inform ation S ystem ) were included.A search was done to establish the distribution ol all the plants on the checklist using the PRECIS records o f the region and this was supplem ented by exhaustive literature searches in the Flora o f southern Africa (1 9 6 3 -1 9 9 3 ).G iddy (1974).W erger (1978).A co m p ariso n w ith check lists o f D w esa N ature Reserve, A lexandria Forest, A ddo Elephant N ational Park, the A m atola M ountain Range and Cape Recife N ature R eserve (Figure 1) w as m ade (M oll no date; Penzhom & O livier 1974;O livier 1983;Phillipson 1987;Phillipson & R ussell 1988).The index o f sim ilarity o f C zekanow ski (IsC ) (as used by G eldenhuys 1992), expressed as percentage, w as used to com pare sim ilarity betw een floras, w here IsC = 200w /(a+b), a and b are the num bers o f species present in each flora, and w is the num ber o f species com m on to both floras (Table 1).
The K ap R iver R eserve flora and three other floras were com pared w ith each other and with the southern A frican flora w ith regard to percentage o f species in the ten largest fam ilies o f each flora (Table 2 The conservation status o f each species on the check list was ascertained from authorities (E.Brink, T. Dold and P Phillipson pers.com m .),herbarium records (GRA, PRE), the R ed D ata L ist o f southern African plants (H ilton-Taylor 1996) and the rare and endangered list o f Lubke et al. (1986).

Flora checklist
A total of 488 species and infraspecific taxa (Appendix) representing 319 genera and 108 families were recorded (Table 3).The largest families are the A steraceae, Poaceae, Fabaceae, Cyperaceae, Liliaceae, Rubiaceae, Euphorbi aceae, A canthaceae, Lam iaceae and Solanaceae.The species to family ratio o f 4:4 com pares well to 3:1 and 4:5 for woody and herbaceous plants respectively in the south ern Cape forests (Geldenhuys 1993).The Asteraceae, Fabaceae and Liliaceae are widespread families, whereas Poaceae, Cyperaceae, Euphorbiaceae and Rubiaceae are subtropical families (W hite 1983).

Distribution ranges
A family which is endem ic to the eastern coast of South Africa, the Achariaceae, has one monotypic genus, namely Acharia tragodes present in the reserve.This rare species occurs in scrub from Uitenhage to Durban (Killick 1976).
Nine taxa are endem ic to the Eastern Cape according to the Red D ata List o f southern African plants (Hilton-Taylor 1996).The database o f Everard (1988) contained a further seven taxa.Three other endem ic taxa identified through literature searches and surveys are: Walafrida albanensis; Romulea autumnalis and Ecbolium flanaganii (Table 4), (Rolfe 1901;De Vos 1983;Vollesen 1989).
B obartia orien talis is abundant in grassland on W itteberg quartzite outcrops in the eastern Cape area from coastal regions to the higher altitudes such as the Z uurberg M ountains.T his is often identified as a

B obartia orientalis-grass\and association (M artin & Noel 1960).
The m ajority o f plants collected had wide ranges and m ost show ed A from ontane or T ongaland-Pondoland affinities.T here is a strong floristic overlap o f these two phytochoria in the eastern Cape region (Lubke et al. 1986) as also reported by C aw e & M cK enzie (1989) for

3.00
-Geramaceae ---   Two taxa have disjunct distributions.Englerodaphne su bco rd a ta is found betw een the Fish R iver and M qanduli in Transkei.and in Tanzania and the Kenyan highlands, a disjunction o f 3 000 km (Cloete 1994); it is rare in the Eastern Cape, and know n only from few sites.D iospyros sim ii has a num ber o f records from King W illiam 's Town to Kentani.and then re-appears at Eshowe and K ranskop in Z ululand (800 km).

Com parison o f the Kap River flo ra with other flo ra s
The Kap River flora is not very similar to any of the other floras, only sharing about one quarter of the species with the Alexandria Forest flora, which shows the greatest similarity.Both the Alexandria Forest and the Dwesa Nature Reserve checklists are based on woody species and are thus not fully representative.Three taxa that are endemic to the Alexandria Forest arc not found in the Kap River.O f the species found in the Kap River Reserve which are not present in Alexandria, several such as Englerodaphne subcordata, Asparagus falcatus, Protorhus longifolia, Rlius crenata, R. fastigiata, Pavetta capensis and Rothmannia globosa, are possibly at their southernmost limit at the Fish River.
The A m atole M ountains show ed the second closest sim ilarity though the range is further away, at a much higher altitude (2 0 0 -7 0 0 m asl).with a greater tem pera ture range ( -6° to 40°C ) and a higher rainfall (7 5 0-1 5 0 0 m m ) (Phillipson 1987).It is possible that a m ajor tribu tary o f the Fish, the Kat River, w hich partly drains the A m atole M ountains, has served as a m igration route for the A from ontane elem ents to the coast and conversely, for the T ongaland-Pondoland elem ents inland.

Rare and Endangered component
The search on the database o f Everard (1988) o f rare and endangered plants produced two taxa classed as vul nerable, five as rare and six as protected plants (Table 5).A further seventeen were listed as 'uncertain w hether endangered or n o t'.In the R ed D ata List o f southern African plan ts (H ilton-T aylor 1996), E ncephalartos altensteinii and G asteria croucherii are listed as vulner able and Homalium rufescens as rare.The cycads are the m ost seriously threatened fam ily (Zam iaceac) in the Eastern Cape and three species of Encephalartos are pre sent in the reserve.
Ecbolium flanaganii is not closely related to other taxa in the genus.Its distribution range is lim ited, with small population num bers and few collections.These factors com bine to give the species a very high priority rating for protection (Hall 1993).
The A m atole M ountains have 10 rare and endangered taxa in com m on with the Kap River Reserve, A lexandria Forest has six, D w esa seven.Cape Recife two and A ddo one.

CONCLUSIONS
The Kap River Reserve has a rich and diverse flora and shows the greatest similarity with the Alexandria Forest.However, it also has a similarity with the Amatole Mountain flora.These findings confirm the relationship o f the Eastern Cape flora with those of the Afromontane region and the Tongaland-Pondoland regional mosaic (White 1983).
The reserve has nineteen taxa that are endem ic to the Eastern Cape and ten o f the taxa that are classified as vulnerable and rare in the Eastern Cape (Everard 1988;H ilton-Taylor 1996).M ore than one quarter o f the plants  M arker & Russell (1984) suggest that all the Eastern Cape forests are 'relict and.... that each locality has a characteristic species spectrum and exists by ecological and historical accident'.The conservation of this pristine region as a reserve is thus a great asset in the preserva tion o f the Eastern C ape flora.

AC KNO WLEL)G EM ENTS
The U niversity o f Transkei is acknow ledged for a study grant to the first author.The A lgoa Regional Council fund ed several collecting trips to the Kap River Reserve and the reserve manager.Phil Cripps is thanked for his assis tance.The staff o f the Schonland Herbarium, Albany M useum, G raham stow n were always very helpful and encouraging.Peter Phillipson is thanked for helping with the databases and with identifications.Tony Dold and Estelle Brink gave invaluable help with the identifications.Thanks are due to Vicky Everitt.Em m a Bruce-Miller, Deon Gibson and Tony Dold for additional collections.

FIGURE 2 .
FIGURE 2.-The Kap River Reserve, stippled area; planned extension o f the Reserve, lined area.

A
PPE N D IX : C H E C K L IS T O F TH E V A SCU LA R PLA N TS O F TH E KAP RIV ER RESERVE.EA STERN C A PE After the name o f the author(s) o f the taxon, the sequence of annotation is as follows: 1. Conservation status: E, Endangered; ECE, East Cape Endemic; I, Indeterminate; PRO.Protected; R, Rare; V, Vulnerable; U, Uncertain 2. Collector abbreviations: AB = A. Burchmore; AJG = A. Jacot Guillarmod; AAM = A.A. Mauve; BRI = Botanical Research Institute; EBM = E. Bruce-Miller; ECC = E. Cloete; EMH = E M. Hunter; D G = D. Gibson; TD = T. Dold; TD A BP = T Dold & B Pemberton, MJW = M J. Wells; PBP = PB Phillipson; P C = P. Cnpps; PG = PB.Goldblatt; PM = P. Macowan; RAD = R A. Dyer; RDAB = R.D.A Bayliss; RS = R. Story; VE = V.Everitt 3. Collection number: specimens without collector numbers are designated s.n. 4. Authors o f plant names follow Brummitt & Powell (1992

TABLE I -Similarity between the flora of the Kap River Reserve and other areas calculated according to the index of similarity of Czekanowski
(IsC).IsC = 200w/(a+b), where a and b are the numbers of species present in each flora, and w is the number o f species

common to both floras Region IsC Alexandria Forest 26.56 Amatole Mountains 21.14 Addo Elephant Park 2 0 7 8 I)wesa Reserve 16 96 Cape Recife Reserve 11.80 141TABLE 2 .-Comparison of four regional floras and that of the south ern African flora with regard to percentage o f species in the ten largest families of each flora Family Kap Cape Rec * Dwesa** Addo+ sthn Afr.»
-9.36 . .-Iridaceae -2.31 -.
' Olivier 1983; ** Moll no date: data o f only woody spp.available; + Penzhom & Olivier 1974; • Goldblatt 1978 T ranskei.P odocarpu s fa lc a tu s , A p o d ytes d im id ia ta subsp.dim idiata.Rapanea m elanophloeos, Nuxia flo ribunda and Olea capensis subsp.capensis are character istic w oody species o f the A fro m o n tan e region.Trichocladus is an endem ic genus o f the A from ontane regional centre o f endem ism (W hite & M oll 1978) and is represented by T. ellipticus in the reserve.Harpephyllum caffrum and Hippobromus pauciflorus are endem ic to the Tongaland-Pondoland region.Thirty seven taxa found in the reserve are at or near their southernm ost limit.

Table 4
reveals that aside from the succulent families, the Kap River Reserve has many o f the families that charac terise the three neighbouring floras.Some of the families of the Kap River flora are not representative of the subtropical Pondoland-Tongaland element i.e.Cyperaceae.Rubiaceae.Euphorbiaceae and Acanthaceae.Families such as Iridaceae.A izoaceae and Ericaceae that have many Cape or Karoo representatives are not well represented here.

Not Threatened that
are know n to he in a precarious situation in the Eastern C ape are present in the Kap River Reserve.It is the southernm ost lim it for a num ber of Tongaland-Pondoland species and the northernm ost limit for a few Cape elem ents.