Johannesburg Botanical Gardens)
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Flora Habitat scan of The wetland on the Remainder of the farm Braamfontein 53-IR (Johannesburg Botanical Gardens) October 2016 Report author: Mrs. P. Lemmer (B.Sc., Pr.Sci.Nat.) Flora Report: Johannesburg Botanical Gardens October 2016 1 of 8 pages DECLARATION OF INDEPENDENCE I, Petro Lemmer (440129 0025 085) declare that I: am committed to biodiversity conservation but concomitantly recognize the need for economic development. Whereas I appreciate the opportunity to also learn through the processes of constructive criticism and debate, I reserve the right to form and hold my own opinions and therefore will not willingly submit to the interests of other parties or change my statements to appease them abide by the Code of Ethics of the S.A. Council for Natural Scientific Professions act as an independent specialist consultant in the field of botany am subcontracted as specialist consultant by Galago Environmental CC for the proposed Johannesburg Botanical Gardens upgrading project described in this report have no financial interest in the proposed development other than remuneration for work performed have or will not have any vested or conflicting interests in the proposed development undertake to disclose to Galago Environmental CC and its client as well as the competent authority any material information that have or may have the potential to influence the decision of the competent authority required in terms of the Environmental Impact Assessment Regulations, 2014. Petro Lemmer Pr.Sci.Nat (400567/15) Flora Report: Johannesburg Botanical Gardens October 2016 2 of 8 pages TABLE OF CONTENTS 1. INTRODUCTION .................................................................................................. 4 2. STUDY AREA ...................................................................................................... 4 2.1 Regional vegetation ....................................................................................... 4 2.2 The study site ................................................................................................. 4 3. METHODS ........................................................................................................... 5 4. FINDINGS ............................................................................................................ 5 5. PROVISIONAL MITIGATING MEASURES .......................................................... 8 6. CONCLUSION ..................................................................................................... 8 7. REFERENCES ..................................................................................................... 8 FIGURES: Figure 1: Locality map of the study area ..................................................................... 4 Figure 3: Dense clumps of plants assumed to be Iris pseudacorus in the dam ........... 6 Figure 4: Dense stands of the category 1b invasive species Pontederia cordata ....... 7 Figure 5: Eucalyptus trees in the riparian zone are considered Category 1b invasive species. ................................................................................................................ 7 Flora Report: Johannesburg Botanical Gardens October 2016 3 of 8 pages 1. INTRODUCTION Galago Environmental was appointed to evaluate the vegetation along the wetland on the Remainder of the farm Braamfontein 53-IR (Johannesburg Botanical Gardens), scheduled for upgrading. 2. STUDY AREA 2.1 Regional vegetation The study site lies in both the 2627BB (Roodepoort) and the 2628AA (Johannesburg) quarter degree squares with most of the drainage line running through the 2628AA q.d.s. Mucina & Rutherford (2006) classified the area as Egoli Granite Grassland, with archaean granite and gneiss of the Halfway House Granite at the core of the Johannesburg Dome supporting leached, shallow, coarsely grained, sandy soil poor in nutrients. This grassland falls within a strongly seasonal summer-rainfall region and very dry winters with frequent frosts. This vegetation unit is considered endangered. Its conservation target is 24%. Only about 3% of this vegetation unit is conserved in statutory reserves and a few private conservation areas. More than two-thirds of the unit has already undergone transformation, mostly by urbanization, cultivation and by building of roads. Current rates of transformation threaten most of the remaining unconserved areas. 2.2 The study site The 99,3894 ha study site comprises the Johannesburg Botanical Gardens and lies along Thomas Bowler Street in Emmarentia and is situated north-east of, and abuts, Beyers Naude Drive opposite West Park cemetery (Figure 1). A drainage line that runs to the Braamfontein Spruit originates in Melville Koppies Nature Reserve to the south of the site and runs from south to north-east through the site. Two earthen weirs that form plant-filled dams, lie in the drainage line in the southern half of the site and the large Emmarentia dam, with concrete weir, lies in the drainage line in the northern half of the site. Figure 1: Locality map of the study area Flora Report: Johannesburg Botanical Gardens October 2016 4 of 8 pages According to the GDARD C-Plan 3.3 the site is situated within an Ecological Support Area with a Critical Biodiversity Area, south of the site on the Melville koppie (Figure 2). Figure 2: Critical Biodiversity Area and Ecological Support Area. 3. METHODS Locality maps were obtained from Planet GIS and information about the Critical Biodiversity Areas and Ecological Support Areas were obtained from the GDARD C-Plan 3.3. The study site was visited on 21 March 2016 to examine the vegetation along the drainage line of the site and to determine the extent of invasion of the wetland by alien species declared as invasive species in terms of the National Environmental Management: Biodiversity Act, 2004 (Act No. 10 of 2004). 4. FINDINGS The drainage line is infested with at least 19 alien invasive species of which one is a Category 1a invasive species, 13 are Category 1b invasive species, three are Category 2 invasive species and two are Category 3 invasive species. A list of these species is shown in Table 1. Table 1: Some of the alien species observed in the drainage line and wetland. INV SCIENTIFIC NAME COMMON NAMES CAT Acacia dealbata* 2 Silver wattle / Silwerwattel Acacia melanoxylon* 2 Australian blackwood / Australiese swarthout Agrimonia procera* 1b Agrimony / Geelklits Argemone ochroleuca* 1b Mexican poppy / Bloudissel Arundo donax* 1b Spanish reed / Spaanse riet Canna indica* 1b Indian shot / Indiese kanna Cirsium vulgare* 1b Scotch thistle / Skotse dissel Cortaderia sp* 1b Pampas gras / Pampasgras Eucalyptus camaldulensis* 1b Red river gum / Rooibloekom Gleditsia triacanthos* 1b Honey locust / Driedoring, soetpeul Ipomoea purpurea* 3 Morning glory / Purperwinde Flora Report: Johannesburg Botanical Gardens October 2016 5 of 8 pages INV SCIENTIFIC NAME COMMON NAMES CAT Iris pseudacorus* 1a Yellow flag Mirabilis jalapa* 1b Morus alba* 3 Common mulberry / Gewone moerbei Pinus spp.* Various spp 1b Pine trees/ Dennebome Pontederia cordata* 1b Pickerel weed / Jongsnoekkruid Populus alba* 2 White poplar / Witpopulier Tecoma stans* 1b Yellow bells / Geel jacaranda Verbena bonariensis* 1b Purple top / Blouwaterbossie INV CAT = Invasive species category Invasive species are controlled by the National Environmental Management: Biodiversity Act, 2004 (Act No. 10 of 2004) – Alien and Invasive Species (AIS) Regulations which became law on 1 October 2014. Category 1a: Invasive species which must be combatted and eradicated. Any form of trade or planting is strictly prohibited. Category 1b: Invasive species which must be controlled and wherever possible, removed and destroyed. Any form of trade or planting is strictly prohibited. Category 2: Invasive species, or species deemed to be potentially invasive, in that a permit is required to carry out a restricted activity. Category 2 species include commercially important species such as pine, wattle and gum trees. Plants in riparian areas become Category 1b invasive species. Category 3: Invasive species which may remain in prescribed areas or provinces. Further planting, propagation or trade, is prohibited. Plants in riparian areas become Category 1b invasive species. Figure 2: Dense clumps of plants assumed to be Iris pseudacorus in one of the dams Flora Report: Johannesburg Botanical Gardens October 2016 6 of 8 pages Figure 3: Dense stands of the category 1b invasive species Pontederia cordata Figure 4: Eucalyptus trees in the riparian zone are considered Category 1b invasive species. Red and orange list species: No red or orange list species occur within the botanical gardens, and especially the drainage line since most of the vegetation were planted or is invasive/alien species. The following Red/Orange List plant taxa have been recorded from the farm on which the study site is situated / within 5km of the study site. Adromischus umbraticola subsp. umbraticola Cineraria austrotransvaalensis Holothrix randii All three of these species are species that only occur on koppie/ridge areas such as the Melville koppies adjacent to the site. These species will however not be influenced by the proposed development since there are fences and large roads between the botanical gardens and the Melville koppies and no buffers are proposed around those species, should they occur on the Melville koppies site. Flora Report: Johannesburg Botanical Gardens October 2016 7 of 8 pages 5. PROVISIONAL MITIGATING MEASURES The following