The vegetation of the southern Langeberg, Cape Province. 2. The plant communities of the Marloth Nature Reserve

The Marloth Nature Reserve, encompassing the mountain catchments of the southern Langeberg immediately above Swellendam, Cape Province. South Africa, is described. The vegetation of the reserve was sampled along a transect representing the variation in plant communities over the range from the lower south to the lower north slopes. Eighty-three sample sites were subjectively located in mature stands of fynbos vegetation (> 10 years old). The relev£ data were initially classified using TWINSPAN and then refined by Braun-Blanquet (BB) phytosociological procedures. The Afromontane Forest patches which occur mainly on the lower south slopes were not sampled but are briefly discussed. The fynbos plant communities are described, based on tables, and a hierarchical classification is proposed.


INTRODUCTION
This paper is the second in a series describing the plant communities of the southern Langeberg, Cape Province.The fynbos plant communities occurring in the Marloth Nature Reserve (Swellendam State Forest) are described and classified.The Afromontane Forest patches found in the study area were not sampled but are briefly discussed based on the studies of McKenzie (1978).

Location
The Marloth Nature Reserve (MNR) is situated in the mountain catchments of the southern Langeberg above the town of Swellendam (Figure 1).In 1928 a deputation of Swellendam residents petitioned the Minister of Lands and Forestry, General Kemp, to set aside a part of the mountain behind Swellendam as a nature reserve.The well-respected chemist and botanist Dr Rudolf Marloth proposed approxi mately 190 ha on the lower slopes of the Langeberg behind Swellendam, as a suitable area.This area which included the forest patches of Koloniesbos and Duiwelsbos, was proclaimed as a nature reserve and named in honour of Dr Marloth (Luckhoff 1981).the route of the Swellendam Hiking Trail to Goedgeloof Hut on the extreme lower north slopes of the range.This route gave ready access to the area.Although the transect covered a narrow belt and consequent relatively small area compared with the whole MNR, it allowed for sam pling of the variety of fynbos plant communities present (Figure 2).

Physiography
The south slopes of the Langeberg above Swellendam are steep and rise rapidly to the famous 'Clock Peaks' (Figure 3).On the lower south slopes, however, the steepness is broken by the 'Plaat' at an elevation of approximately 500 m.This plateau is the result of downfaulting of the Worcester Fault along this part of the Langeberg Range.On the north side of 10 to 12 O'Clock Peaks the slopes drop steeply into the Boskloof intermontane valley (Figure 4

Soils
The soil forms (Soil Classification Working Group 1991) occurring in MNR are summarized in  Phytosociological tables were compiled by obtaining a 'first approximation' classification using TWINSPAN (Hill 1979) and then by successive refinement using Braun-Blanquet procedures with PCTables (Boucher unpublished).
Each community is described following the order in the proposed classification; the structural description follows the system advanced by Campbell et al. (1981).Relation ships between the communities described here and com munities described in other studies of mountain fynbos are given as far as possible.3.At the lower levels of the TWINSPAN classifica tion there is some agreement between this analysis and the BB-classification, however, the latter classification is favoured since it yields fewer units that are more easily interpreted and identified in the field.

Cliffortia serpyllifolia Shrublands of the lower south slopes
The shrublands of the lower south slopes of the Lange berg at Swellendam are conspicuously dominated by Cliffortia serpyllifolia which is hardly found higher than the edge of the 'Plaat'.The edge of the 'Plaat' represents the contact between the TMG sediments and the basement rock of the Malmesbury Group with which C. serpyllifolia appears to be strongly associated.A logical separation of the lower slope plant communities on Malmesbury Group sediments [Main Quartzite of the Lower Group of the Boland Formation (De Bruyn et al. 1974)] (Table 2) from the Erica hispidula shrublands (Table 3) of higher eleva tion on TMG sediments is therefore possible.It is impor tant to note, however, that many of the species are common to both shrubland types.

Cliffortia serpyllifolia-W iddringtonia nodiflora Shrublands
Only one poorly defined shrubland community is included here.This community lies at the transition between the Erica hispidula Shrublands of the high elevation zone and the Cliffortia serpyllifolia-Leucaden dron eucalyptifolium Shrublands.This community is represented by only two releves (BI & 152), found on the rocky ridge marking the edge of the 'Plaat', at an altitude of 580 m.Sample plot 131 was situated on the north-north-east aspect of the ridge, with a slope of 14°, and sample plot 152 was located on the south-south-west aspect of the ridge with a slope of 7°.These differences appear to have affected dominance only.The soils are lithosols and are of the Mispah and Glenrosa Forms at the two sites respectively.

Widdringtonia nodiflora-Rhodocoma fruticosa
The Mid-dense Graminoid Shrubland is dominant and contains all the differential species.Emergent from this stratum ( < 1 m) is a Mid-high Open to Mid-dense Shrub land, with dominants as above.In relev£ 152, Laurophyllus capensis dominates the upper stratum.

Erica hispidula Shrublands o f the high elevation zone
The Erica hispidula Shrublands described in this paper are broadly equivalent to those described by McDonald (1993).E. hispidula is present in all but one community, the Hypodiscus aristatus-E rica multumbellifera Shrub lands.Speculation as to the reason for this absence is given below in the description of the latter community.Restio inconspicuus, which assumes a distinctive yet subordinate position to E. hispidula in the shrublands of Boosmans bos Wilderness Area (McDonald 1993), is less prominent in MNR.Of particular note in this community is the presence of Erica omninoglabra (single occurrence in releve 179), a rare Langeberg endemic species found sprawling amongst the matted restioid understorey, Klattia partita (Iridaceae), a shrubby species with non-fugaceous flowers and the endemic Stylapterus dubius (Penaeaceae).3).
Structural formation: Low to Mid-high Closed Grami noid Shrubland.

Blaeria coccinea and certain graminoids, particularly
Chrysithrix capensis and Tetraria flexuosa.Psoralea pinnata and Widdringtonia nodiflora occur as sparse emergent shrubs up to 2 m high in some stands.3).It may be argued that description of the Erica hispidula-H ypodiscus aristatus Shrublands based on three releves is tenuous.However, this indicates inadequate sampling, not the non-existence of the com munity.This community (Figure 15) is generally Open to Middense Graminoid Shrublands with a Mid-high Open to Closed Ericoid Shrubland Overstorey (see Campbell et al. 1981).This community is found on the north-facing slopes of Goedgeloof Ridge and on rock outcrops in the Boskloof Valley.The rocky substrate, with a usual high percentage of boulders and exposed bedrock, results in shallow lithosols (< 0 .20 m) classified here as Glenrosa and Mispah Forms.In Boskloof the community was sampled at 920 m (Releves 178 & 201) whereas on Goedge loof Ridge the mean altitude for the three sample plots (Releves 193,197,198) was 1 173 m.The area sampled by the latter plots is mesic and represents a transition zone from the cooler, moister areas south of Goedgeloof Ridge to the drier lower slopes (see Table 4

and communities P&Q).
Phylica pinea is the most constant differential species in this community.Both Tetraria therrnalis and Cerato caryum decipiens have a wider distribution on the dry, north-facing slopes (see Table 4), therefore their differen tial value is diminished.Erica atropurpurea is faithful to this community but has a low cover-abundance.Domi nance in the mid-high shrub stratum is held by Erica versicolor, which typically favours north-facing rocky outcrops (McDonald 1993).The lower stratum does not have a strikingly dominant species but Tetraria ustulata does stand out as having a higher cover-abundance than most.Relationships: some affinities to the Acid Sand Flats Community (Boucher 1978).

Hypodiscus aristatus-Erica versicolor
The description of this community (Figure 17) is based on two releves, 194 & 195.This small sample size places a question on the validity of this community concept but since it is distinctly different from all other communities described, it is retained for completeness.These shrub lands show affinity to the shrublands of high elevation on shallow soils (Table 3).
The Hypodiscus aristatus-Erica multumbellifera Shrub lands were sampled at 1 180 and 1 300 m on the north slopes of Goedgeloof Ridge.The sites were almost level with a mean gradient of 6°.The Cartref Form soils were 0.2-0.4m deep and almost no rock was exposed on the surface.Litter was very low and vegetation cover exceeded 95%.
Releve 194 had a more abundant graminoid component than Releve 195, whereas Erica melanthera was more abundant in the latter sample.Presence of E. melanthera suggests impeded drainage in the soil, and a possible explanation for the existence of this community is wet soil conditions for part of the year and extremely dry soil for the remainder.This would preclude species intolerant of such conditions.A similar regime was found by Boucher (1978)  This community is transitional between the communi ties of the cool, moist high elevations and those of the highly insolated, drier north-facing slopes o f Goedgeloof Ridge described below.The transition is reflected in the species shared with both groups of communities.

Leucadendron eucalyptifolium Shrublands of the extreme north slopes
The two shrubland communities included in this section show strong floristic affinities to the shrublands on the lower south slopes on the sample transect.This is most likely due to the apparent equivalent nutrient status of the soils of the two extreme ends of the transect.Further investigation of these respective communities and their underlying environmental relationships is necessary before this hypothesis can be conclusively tested.was classified as Lamotte Form, which is exceptional for this area.Surface rock cover is highly variable, ranging from 6-85% and the habitat is well drained.

Leucadendron eucalyptifolium-Erica melanthera
As delimited here, the Leucadendron eucalyptifolium -Erica melanthera Shrubland is not floristically clearly defined.It appears that although a community definition is possible, the community represents fragments of two or perhaps more undersampled and undefined communi ties.They are grouped together by virtue of commonness of a few widespread 'differential' species but the 'strings' of single occurrences in Table 4 support the above con clusion.As defined, the community shows affinity to the communities of the lower south slopes and the high elevation zone described above under sections 1-3.How ever, high cover-abundance of Leucadendron eucalypti folium and presence of Elegia galpinii, Hypodiscus striatus and Anomalanthus scoparius clearly place this commu nity apart from those described above.4).Further sampling would clarify whether this is due to too few samples or that the communities are simply poorly represented in this part of the Langeberg.It was not possible to obtain further samples of these com munities in this study because the area had been burnt soon after the initial samples were taken.

The Leucadendron eucalyptifolium-Erica melanthera
It may be argued that a community may be character ized by one or two species whose presence is a result of differential post-fire recruitment (Van Wilgen et al. 1992).This possibility would increase if the sample size for a given community is small, which in turn could lead to an artificial classification.However, each community is not based solely on the character species but is based on a specific combination of species for each community.These combinations should be seen as the key to identifying each community.

The complexity of the metamorphosed Malmesbury
FIGURE 1. -Map of the mountains of the Fynbos Biome show ing the position of the Langeberg and the location of the Marloth Nature Reserve (MNR) transect.B, Barrydale; C, Cape Town; G, George; H. Heidelberg; M. Mossel Bay; P. f\>rt Elizabeth; R, Riversdale; S, Swellen dam and W, Worcester.

FIGURE
FIGURE 2 .-Portion of topographical map 3320CD Scheepersrus, showing part of the MNR with positions of the sample plots.(Map reproduced under Government Printers copyright authority dated 30 October 1991).
photographs were available.Consequently plots were sub jectively placed in what were taken as the major landscape features and plant communities.The rectangular sample quadrats were 50 m2, subdivided into 10 equal-sized sub plots to facilitate data collection (McDonald 1988, 1993).Only permanently recognizable species were recorded.Geophytes and annuals encountered were noted but not used in the analyses.The Braun-Blanquet cover-abundance scale (Mueller-Dombois & Ellenberg 1974; Werger 1974) was applied.A border zone of 1.5 m from the perimeter of each plot was rapidly searched for any additional species not found in the marked plot.

Fynbos
These relationships were determined by comparing the floristic composition of the communities of this study with the respective communi ties of other studies as indicated below [note that Camp bell (1985) gave 'floristics' for each of his lowest level structural units].VEGETATION The greater part of the Marloth Nature Reserve is covered by sclerophyllous fynbos typical of the mountains of the western and southern Cape (Taylor 1978; Kruger 1979).Afromontane Forest communities in the MNR are confined to moist kloofs on the south side o f the Lange berg range.Afromontane Forest Numerous mixed evergreen Afromontane forests (Geldenhuys 1989) are found in the MNR.These forests were exploited for hardwood timber in early colonial days, for wagon-making, furniture and general construction.The accessible forest patches are known variously as Koloniesbos, Duiwelsbos, Doktersbos and Grootbos with less accessible forests being found in Boskloof, Hermitage Kloof, Wolfkloof and Leeukloof.McKenzie (1978) described the 'Rapanea melanophloeos-Hartogiella schinoides-Podocarpus latifolius Forest Association' as the general type found in the southwestern Cape.This association was divided into three subassociations, two of which are found in the MNR: Cunonia capensis-Platylophus trifoliatus Subassociation and Carissa bispinosa-Canthium ventosum-Canthium mundianum-Pterocelastrus tricuspidatus Subassociation.Only one of the variations of the Cunonia capensis-P.trifoliatus Subassociation, the Cunonia capensis-Todea barbara Variation was identified in MNR, whereas two variations of the second subassociation, Buddleja saligna-Scolopia mundii Variation and Rothmannia capensis-Olinia ventosa-Canthium ventosum-Canthium mundianum Variation were identified (McKenzie 1978).The three variations of forest subassociations identified in MNR occur on a moisture gradient.The Cunonia capensis-Todea barbara Variation occurs in wet situations along streams, the Rothmannia c a p e n sis-O lin ia ventosa-Canthium ventosum -Canthium mundianum Variation is found on seasonally wet to dry sites and the Buddleja saligna-Scolopia mundii Variation on relatively dry sites.
Structural formation: varies from a Low Closed Grami noid Shrubland with Mid-high Emergent Shrubs to a Midhigh to Tall Closed Shrubland with an Open to Mid-dense Graminoid Understorey.Relationships: Enon Mesotrophic Proteoid Fynbos (Campbell 1985).This community (Figure 6) is found at a mean alti tude of 447 m (310-570 m) on the cool lower slopes below the 'Plaat*.The parent rock is Peninsula For mation sandstone and all the soils are classified as Bothalia 23,1 (1993) ) is found on the complex zone of Malmesbury Group sediments which are exposed below the 'Plaat'.There is strong correlation between this com munity and the relatively nutrient rich soils of the Malmes bury Group sediments.The soils of releves 127Erica vestita is a prominent, easily identifiable differen tial species in this community.It has three colour forms, two of which are found on the Langeberg.The colour form found in the Leucadendron eucalyptifolium-Erica vestita Shrublands below the 'Plaat' is pink, whereas in the Erica hispidula-H ypodiscus aristatus Shrublands (described below) the flowers are crimson red.O f further particular note in this community are Lanaria lanata, Cymbopogon marginatus and Erica pubigera which appear to favour soils with a high clay fraction.

FIGURE
FIGURE 6. -The Widdringtonia nodi flora-H i ppia pilosa Shrub lands on the lower south slopes of MNR below the 'Plaat', with tall Leucadendron eucalypti folium in the foreground.
FIGURE 7.-The Leucadendron eucalypti folium -Erica vestita Shrublands found on the com plex zone of Malmesbury Group sediments below the Plaat*.
FIGURE 9 .-TheErica hispidula -Berzelia intermedia Shrublands occurring mainly on the southfacing slopes of the Clock Peaks and Hermitage Ridge, forming a background' to the mosaic o f communities.
FIGURE 11.-The Berjelia interme dia -Grubbia rosmarinifolia Shrublands mainly localized on the south-feeing mid-slopes of the Clock Peaks.Note the midhigh G. rosmarinifolia forming the overstorey.
FIGURE 12.-The Berzelia inter media-Cliffortia grandifolia Shrublands occurring in pat ches over extensive areas of the south slopes of the Clock Peaks and in Boskloof.Note the characteristic tall, slender Cliffortia grandifolia.
FIGURE 14.-The Erica hispidula-Hypodiscus aristatus Shrublands found on the north-to northeast-facing slopes o f the Clock Peak ridge.Cliffortia heterophylla dominates the overstorey in this stand.
in the Acid sand flats communities' where Erica multumbellifera was also found.Further sampling of the Hypodiscus aristatus-Erica multumbellifera Community over a wider range may provide more information about the habitat factors determining the distribution of this com munity.
FIGURE 18.-The Leucadendron eucalyptifolium-Erica melanthera Shrublands are found on the moderately steep north-facing slopes of Goedgeloof Ridge.
Heteropogon contortus, Hypodis cus argenteus, Lanaria lanata, Lobelia capillifolia (i.e.species with four or more occurrences in five releves).Dominant species: L. eucalyptifolium, Tetraria ustula ta, Restio filiformis.Structural formation: Open to Closed Graminoid Shrub land with Mid-high Open Proteoid Shrubland Overstorey.Relationships: in part, this community is equivalent to the Phylica axillaris-Felicia filifolia Community (Ruitersbos) and Passerina obtusifolia-Felicia filifolia Commu nity Leucospermum calligerum is the dominant proteoid in the overstorey.The upper stratum varies from a Midhigh Open to Tall Open Proteoid Shrubland and the lower (dominant) stratum varies from an Open to a Closed Graminoid Shrubland.There are a number of affinities between this Commu nity and the communities of the lower south slopes of the Langeberg above Swellendam.Equally there are numerous similarities between the Leucadendron eucalyptifolium-Hypodiscus argenteus Shrublands and the Cannomois parviflora Shrublands north of Grootberg (McDonald 1993).The Leucadendron eucalyptifolium-Hypodiscus argenteus Shrublands are mesic in character but may once again be represented by a group of releves which through commonness are associated but which may truly be fragments of other communities, e.g.part of the more arid Passerina obtusifolia-Leucospermum calligerum Shrub lands.This requires further clarification.DISCUSSION AND CONCLUSIONSThe classification presented in this study was developed from a phytosociological perspective but with management of the fynbos shrublands of the Langeberg in mind (McDonald 1993).Some of the units defined are limited in extent, and from a management viewpoint it would not be practical to treat them separately from broader vegeta tion units.However, since the classification is hierarchi cal, similar communities are grouped together according to the level of the hierarchy.It is therefore possible for any manager of the fynbos shrublands of the Langeberg to select the appropriate level required for any particular management treatment.Those communities grouped at the same level may then be treated similarly.Two problems have beenencountered with the methods used in this study.Firstly, since no initial stratification of aerial photographs o f the study area was done, some com munities were undersampled.There is no satisfactory way of detecting this before analysis of the data.Both the TWINSPAN and Braun-Blanquet methods of classifica tion have indicated communities that have been under sampled.The most obvious is the P. malouinensis-Tetraria bromoides Shrubland found on the Cedarberg shaleband.Another example is the Hypodiscus aristatus -Erica multumbellifera Shrubland for which a description is given.Ideally this community requires further sampling upon which an adequate description may be based.Frag ments of communities recognized in other parts of the Langeberg are included in the L. eucalyptifolium Shrub lands of the extreme north slopes of the transect.In the TWINSPAN analysis this was shown by releves 185 and 186 being separated from releves 151, 183, 184 and 199 (see also Table Group sediments that occur below the 'Plaat' is reflected in the vegetation occurring in this part of the MNR.Here fynbos communities characterized by constant presence of Cliffortia serpyllifolia are found on soils derived from quartzites and shales.The Afromontane forests also occur on the Malmesbury Group shales, but in this case in moist kloofs.Although it has been stated that P. aurea may be used as a 'marker', indicating the position of the Cedarberg Formation shales in the folded strata along the length of the Langeberg (McDonald 1993), this is a misconception.A large stand of fynbos dominated by P. aurea is found at the base of 10 O'Clock Peak, below the 'Plaat', on Malmesbury shale-derived soil.The response of P. aurea is therefore to the fine-textured shale-derived soils with higher nutrient status, regardless of their lithological origin or stratigraphic position.The vegetation o f the MNR appears more complex than that of the Boosmansbos Wilderness Area (BWA) (McDonald 1993).This could be ascribed to more com plex environmental gradients and a greater diversity of habitats.However, detailed analysis of environmental data is needed to substantiate such a claim.No equivalent of the Restio inconspicuus-Leucadendron eucalyptifoliumShrubland which is widespread in BWA is found in the MNR.The Restio inconspicuus-Antho chortus crinalis Shrublands o f BWA and the Erica hispidula-Berzelia intermedia Shrublands of MNR are essentially similar.The communities on the Cedarberg Formation shale of the two areas are similar except that the Pentaschistis malouinensis-Tetraria bromoides Shrub land is poorer in species.The Cliffortia serpyllifolia Shrub lands of the lower south slopes of MNR have no equivalent in BWA.The reason for the absence of these shrublands or their equivalent in BWA is not clear but it may be due to the absence of shale-derived soils on the lower south slopes of the BWA transect.The Cannomois parviflora Shrublands of BWA are represented in part by the Leucadendron eucalyptifolium Shrublands of the extreme north slopes of the MNR transect, but more extensive sampling and more detailed analysis is necessary to clarify the classification of these communities.Communities identified in different studies from differ ent mountain ranges can not be simply equated (McDonald 1993).At the landscape scale there does not appear to be much difference between the fynbos vegetation of the Marloth Nature Reserve and the Boosmansbos Wilderness Area (McDonald 1993).Apparent differences are more at the level o f communities which are micro-habitat rela ted.Closer examination is therefore required of (i) the patterns of distribution of communities on the Langeberg and (ii) the high turnover of species between communi ties and landscapes on the Langeberg.This is beyond the scope of the present paper but forms a principal part of further detailed analyses of the vegetation and flora of the Langeberg (McDonald unpublished).