Summary
Moderate to high tree counts were seen only in Bloemfontein and Johannesburg, where many alien trees have been planted. Grass and weed pollen was detected in low concentrations at all sampling sites. A new site, Sharpeville, in Gauteng has been added.
Cape Town
Pollen and moulds were found in low concentrations as warmer temperature and sunshine days alternated with cool, misty weather. Trees included cypress (Cupressaceae), sweetgum (Liquidamber), cedar (Cedrus), pine (Pinaceae), yellowwood (Podocarpaceae), plane (Platanaceae), monkey puzzle (Araucaria angustifolia), syringa (Meliaceae), salt cedar (Tamarix), oak (Quercus) and ash (Fraxinus). Weeds were erica (Ericaceae), protea (Proteaceae), sedges (Cyperaceae) and nettles (Urticacae). Moulds were low.
Johannesburg
The main tree pollen season has ended at this site but low concentrations were seen for acacia (Acacia-type), false olive (Buddleia), white stinkwood (Celtis), bushwillow (Combretaceae), cypress (Cupressaceae), ebony (Ebenaceae), sweetgum (Liquidamber), beech (Fagus) mulberry (Moraceae), gum (Myrtaceae), plane (Platanaceae), oak (Quercus), yellowwood (Podocarpaceae) and karee (Rhus/Searsia). Weeds included the daisy family (Asteraceae), sedges (Cyperaceae), plantain (Plantaginaceae) and nettles (Urticaceae). Moulds were low.
Sharpeville
Tree, grass and weed pollen appeared in low concentrations at this sampling site. Trees detected included birch (Betulus), bushwillow (Combretaceae), cypress (Cupressaceae), ash (Fraxinus), mulberry (Moraceae), pine (Pinaceae), yellowwood (Podocarpaceae) oak (Quercus) and gum (Myrtaceae), Weeds were plantain (Plantaginaceae), and moulds were low.
Pretoria
Tree pollen is usually still appearing in the air at this time of year and includes species such as cypress(Cupressaceae), birch (Betulus), acacia (Acacia-type), palm (Arecaceae), oak (Quercus), Australian pine (Casuarina), poplar (Populaceae), bushwillow (Combretaceae), gum (Myrtcaceae), pine (Pinaceae), yellowwood (Podocarpaceae), karee (Rhus/Searsia), mulberry (Moraceae), white stinkwood (Celtis), olive (Oleaceae) and marula (Sclerocarya). Weeds would be the daisy family (Asteraceae), spurges (Euphorbiaceae), protea (Proteaceae), goosefoot (Chenopodiaceae), rush (Juncaceae) and knotweed (Polygonaceae). Moulds would be low. 4-year means are given.
Bloemfontein
A sharp decline in tree pollen occurred at this site as trees neared the end of their pollen release cycle. The dominant trees this week were olive (Oleaceae) and cypress (Cupreessaceae) with moderate concentrations recorded for poplar (Populaceae), false olive (Buddleia), white stinkwood (Celtis), bushwillow (Combretacerae), elm (Ulmaceae), yellowwood (Podocarpaceae), sumac (Anacardiaceae), karee (Rhus/Searsia), oak (Quercus), pine (Pinaceae) and plane (Platanaceae). Weeds were lily (Liliaceae), goosefoot (Chenopodiaceae), pigmyweeds (Crassulaceae), mallows (Malvaceae) and ferns (Polypodiaceae). Grasses were low but increasing. Moulds were low.
Kimberley
There has been little summer rainfall at this site and this is reflected in the low pollen counts. Trees included cypress (Cupressaceae), ebony tree (Ebenaceae), karee (Rhus/Searsia) ash (Fraxinus), olive (Oleaceae), pine (Pinaceae), false olive (Buddleia) and mulberry (Moraceae). No weed pollen was detected and moulds were low.
Durban
Low concentrations for all pollen and moulds were detected in the atmosphere during this sampling week. Trees included acacia (Acacia-type), birch (Betulus), yellowwood (Podocarpaceae), willow (Salix), monkey puzzle (Araucariaceae) and karee (Rhus/Searsia). Weeds were plantain (Plantaginaceae), protea (Proteaceae) and goosefoot (Chenopodiaceae).
Gqeberha
Pollen in the categories: trees, grasses and weeds remained low. Trees included sand olive (Dodonea), the pea family (Fabaceae), waxberry (Morella) and pine (Pinaceae). Weeds were ice-plants (Aizoaceae), the daisy family (Asteraceae), sedges (Cyperaceae), spurges (Euphorbiaceae), the carnation family (Caryophyllaceae), pigmyweeds (Crassulaceae), plantain (Plantaginaceae), ferns (Polypodiaceae), reeds (Restionaceous), nettles (Urticaceae) and mezereum (Thymelaeaceae). Moulds were low.
George
The spore trap is being repaired so no recent counts are available.
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
