The physiography and fynbos vegetation communities of the Zachariashoek catchments, south-western Cape Province

Physiographic and climatic data for a mountain catchment study site at Zachariashoek, near Paarl, Cape Province, are presented. These include slope, aspect, radiation, rainfall, temperature and wind data. Above-ground plant biomass was sampled at seven sites. Mean live biomass was 510 g m- 2 . Features of the dominant vegetation were determined from a systematic sample of quadrats, using the Braun-Blanquet technique, to provide a data base for monitoring change. Additional quadrats were sampled to supplement the systematic sample. The Braun-Blanquet table method was used to define ten vegetation communities, based on 105 of the quadrats. This classification was verified using detrended correspondence analysis (DCA). Descriptions of plant communities ranging from low herblands to woodlands are presented. These include habitat features and listings of differential, prominent and less conspicuous species for each vegetation stratum. Soil moisture and drainage appear to govern community distribution. Descriptions of selected soil profiles in each commmunity are presented. Additional physical factors such as fire and wind may be important in determining vegetation structure. Large seed-reproducing shrubs are rare in the area, and the reasons for and implications of this on the catchment experiments being conducted in the area are discussed. S. Afr. J. Bot. 1985, 51: 379–399 Fisiografiese en klimatologiese gegewens word aangebied vir ‘n bergopvanggebiedstudie-area. Helling, aspek, bestraling, reenval, temperatuur en wind word ingesluit. Monsters van die plantbio-massa is op sewe gebiede bogronds geneem. Die gemiddelde biomassa van lewende materiaal was 510 g m- 2 . Eienskappe van die dominante plantegroei, wat benodig word as basis om veranderinge waar te neem, is bepaal deur sistematiese monsterneming van Vierkante deur middel van die Braun-Blanquet-metode. Monsters van addisionale Vierkante is geneem ter aanvulling van gegewens verkry uit die sistematiese steekproef. Die Braun-Blanquet-tabelmetode en data van 105 Vierkante is gebruik om 10 plantgemeenskappe te definieer. Hierdie klassifikasie is gekontroleer deur gebruik te maak van lopende ooreenstemmings-analise [‘detrended correspondence analysis’ (DCA)]. Die plantgemeenskappe, wat Wissel van laaggroeiende kruidgewasse tot woudplantegroei, word beskryf. Habitatseienskappe en ‘n lys van kenmerkende, uitstaande en minder opvallende spesies word vir elke stratum gegee. Dit skyn asof grondvog en -dreinering bepalend is in die verspreiding van gemeenskappe. Beskrywings van uitgesoekte grondprofiele in elke plantgemeenskap, word gegee. Bykomende fisiese faktore soos vuur en wind, kan ‘n belangrike invloed op die samestelling van die plantegroei he. Hoe struike wat deur middel van saad voortplant, is skaars in die gebied en die redes hiervoor, asook die implikasies hiervan, op eksperimente in die opvanggebied word bespreek. S.-Afr. Tydskr. Plantk. 1985, 51: 379–399