Summary
The public holiday on 21 March made it impossible for aerobiologists to read the pollen strips. Four-year means are given for most of the sites, Grasses are usually moderate to high in Johannesburg, and Kimberley and weeds increase in Pretoria and Potchefstroom.
Cape Town
No significant pollen or mould concentrations were measured during this sampling period. Trees identified included mulberry (Moraceae), poplar (Populaceae) and elm (Ulmaceae). Weeds were the daisy family, pigmyweeds (Crassulaceae), sedges (Cyperaceae), waxberry (Morella) and plantain (Plantaginaceae). Four-year means are shown.
Johannesburg
Pretoria
The grass and tree concentrations at this site are usually low at this time of year. Tree pollen identified includes mulberry (Moraceae) and bushwillow (Combretaceae). Weeds are usually low to moderate and the daisy family (Asteraceae), goosefoot (Chenopodiaceae) and the carnation family (Caryophyllaceae) are commonly seen. Moulds have been insignificant during this time period.4 -year means given.
Bloemfontein
No significant pollen or mould concentrations were measured during this sampling period. Trees identified included mulberry (Moraceae), poplar (Populaceae) and elm (Ulmaceae). Weeds were the daisy family, pigmyweeds (Crassulaceae), sedges (Cyperaceae) and plantain (Plantaginaceae).
Kiimberley:
Grasses fluctuate from low to high during this time of year, depending on weather patterns. Scant tree pollen is seen but karee (Rhus/Searsia) and gum (Myrtaceae) are infrequently seen. Similarly insignificant weed counts might include ferns (Polypodiaceae) or plantain (Plantaginaceae). Moulds are usually low.
Durban:
During most of the month of March moulds are high. Tree and weed pollen have a low presence in the air and trees detected might be gum (Myrtaceae) or birch (Betula), Weeds are invariably ferns (Polypodiaceae) and ragweed (Ambrosia).4 -year means are given.
Gqeberha:
Tree types typically detected at this time of year are white stinkwood (Celtis), Australian pine (Casuarina) and waxberry (Morella). Weed pollen is normally scarce and would include sedges (Cyperaceae), lily (Liliaceae), slangbos (Stoebe-type) and erica (Ericaceae), Moulds are usually low. Four –year means are given.
Potchefstroom
Pollen concentrations were insignificant in all three categories. No tree pollen was detected and the weeds were ragweed (Ambrosia), pigweed (Amaranthaceae), the daisy family (Asteraceae) and sedge. (Cyperaceae) Moulds were low.
George
Low concentrations were seen for all pollen categories. Trees included olive (Oleaceae), ash (Fraxinus) and false olive (Buddleja). Fungal spores/ moulds were low but increased after rain when small spikes were seen for ascospores and basidiospores (includes mushrooms). Last week’s findings are given.
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
