Summary
Tree pollen is increasing rapidly inland as the trees begin their spring flowering cycle. The pollen of plane, oak, olive, mulberry and cypress is already significant in Johannesburg, Pretoria and Bloemfontein. No significant grass, weed or mould concentrations were recorded.
Cape Town
Pollen in all three categories remains low as low temperatures and rain continued at this site with occasional dry, sunny days. Trees included pine (Pinaceae), oak (Quercus) and cypress (Cupressaceae). Weeds were mugwort (Artemisia) and moulds were low.
Johannesburg
Trees reached significant concentrations at this site. High concentrations of plane (Platanaceae), mulberry (Moraceae) and beech (Fagus) were seen and other flowering trees included hackberry (Celtis), ash (Fraxinus), gum (Myrtaceae), pine (Pinaceae), poplar (Populaceae), oak (Quercus) and karee (Rhus/Searsia). Weeds were lily (Liliaceae), the daisy family (Asteraceae) and slangbos (Stoebe-type). Moulds remained low.
Pretoria
4-year means are given. Trees begin their pollen release cycle at this site at this time of the year. In previous years significant concentrations were consistently seen for cypress (Cupressaceae), mulberry (Moraceae) and poplar (Populaceae). Other flowering trees whereas (Fraxinus), oak (Quercus, birch (Betula), pine (Pinaceae), karee (Rhus/Searsia) Australian pine (Casuarina) and hackberry Celtis). Weeds have included erica (Ericaceae), the daisy family (Asteraceae), plantain (Plantaginaceae), spurges (Euphorbiaceae) and the carnation family (Caryophyllaceae). Moulds have been low.
Bloemfontein: Tree pollen increased and included the sumac family (Anacardiaceae), cypress (Cupressaceae), gum (Myrtaceae), olive (Oleaceae), mulberry (Moraceae), pine (Pinaceae), plane (Platanaceae) and karee (Rhus/Searsia). Grasses were scarce. Weeds were mugwort (artemisia), the daisy family (Asteraceae), pigmyweeds (Crassulaceae), erica (Ericaceae) and ferns (Polypodiaceae) Moulds were low.
Kimberley
The continued dry weather with cold nights depressed moulds weeds and grasses but the trees are beginning to flower and cypress (Cupressaceae) and gum (Myrtaceae) pollen was seen. Now weed or grass pollen was detected and moulds were low but evidence of grass burning was seen in the numbers of burnt stamens and nematodes.
Durban
No grass pollen was detected during this sampling period. The trees were low but more varied that during the past few weeks and included cypress (Cupressaceae), gum (Myrtaceae), mulberry (Moraceae, birch (Betulaceae), plane (Platanaceae), hackberry (Celtis), oak (Quercus), pine (Pinaceae) and yellowwood (Podocarpaceae). Weeds were mezereum, protea (Proteaceae) and goosefoot (Chenopodiaceae). Moulds were low.
Gqeberha
At this sampling site, low concentrations of all pollen and moulds was seen. Grasses were low, no tree pollen was seen and weeds included low concentrations of the daisy family (Asteraceae) and reeds (Restionaceae).
Potchefstroom
This site is not operating.
George
No grass pollen was detected at this site. Trees are still low, but more varied as spring approaches and include cypress (Cupressaceae), pecan (Carya), pine (Pinaceae) and bushwillow (Combretaceae). Weeds are erica (Ericaceae) and pondweed (Potomageton) moulds were found in low concentrations.
Reference Range
Grass: Low: 0-5 Moderate: 6-20 High: 21-200
Trees: Low: 0-15 Moderate: 16-90 High: 91-1500
Weeds: Low: 0-10 Moderate: 10-50 High: 51-500
Moulds: Low: 0-900 Moderate: 900-2500 High 2500-25000
Unit: per cubic metre
