Flora & Fauna Survey & Ecological Assessment (pdf. 5MB)

More documents

Recommendations

Info

Flora & Fauna Survey & Ecological Assessments – 35 Water Street Wahroonga FAMILY SCIENTIFIC NAME COMMON NAME CLASS* Ochnaceae Ochna serrulata Mickey Mouse Bush/Ochna 4 Oxalidaceae Oxalis spp. Oxalis 5 Rosaceae Rubus fruticosus spp agg Blackberry 3 Commelinaceae Tradescantia fluminensis Wandering Jew 4 *Actions Required For Noxious Weed Classes 1 The plant must be eradicated from the land and the land must be kept free of the plant 2 The plant must be eradicated from the land and the land must be kept free of the plant 3 The plant must be fully and continuously suppressed and destroyed 4 The growth and spread of the plant must be controlled according to the measures specified in a management plan published by the local control authority and the plant may not be sold, propagated or knowingly distributed. 5 The requirements in the Noxious Weeds Act 1993 for a notifiable weed must be complied with. 3.4 Description of the Vegetation in the BGHF Habitat Area The vegetation in the mapped BGHF Habitat Area (Smith & Smith 2006) mainly comprised a canopy of original Sydney Blue Gums (Eucalyptus saligna) and the occasional Rough-barked Applebox (Angophora floribunda), with numerous planted specimens also occurring (Three Wise Men, 2007). Plantings included non-indigenous or ‘generally Australian’ species, and (in the historic arboretum) many significant specimen trees from overseas. The canopy height was typically 15-30 metres. The native understorey had been cleared over 100 years previously in order to establish exotic gardens, an arboretum and extensive lawns. In some locations, soil levels were altered to construct terraces, as at the croquet lawn, stone retaining walls, grottos and pathways. The results of the 11 quadrats established within the mapped BGHF Habitat Area are presented below. See Figure 3.1 for location of the quadrats. Exotic vegetation dominated the understorey at the time of the original (2005), subsequent (2006, 2007 and 2011) and current surveys (May/June 2012). The most commonly occurring environmental weeds recorded were: Large-leaved Privet (Ligustrum lucidum), Small-leaved Privet (Ligustrum sinense), Ground Asparagus (Asparagus aethiopicus var. densiflorus), Japanese Honeysuckle (Lonicera japonica), Mickey Mouse Plant (Ochna serrulata) and Morning Glory (Ipomoea indica). Locally indigenous (BGHF) species generally comprised only a small part of the vegetation (2.09%), often being limited to a few individuals within a quadrat. One (1) area in the south (sampled in quadrat 7) contained a large proportion of commonly-occurring grasses such as Weeping Meadow-Grass (Microlaena stipoides) and smaller proportions of Basket Grass (Oplismenus aemulus). Nine (9) quadrats were surveyed in similar locations to the 10 quadrats first surveyed by Consultant Botanist David Thomas for Cumberland Ecology (2007) in order to provide an opportunity to compare any change in condition of the vegetation. Quadrat 10 was located north of the original quadrat 10 of Cumberland Ecology. The extra quadrat (quadrat 11) was located in the western part of the former croquet lawn to determine whether or not the vegetation here might conform to BGHF generally (see Figure 3.1). Results from 2007 and 2012 quadrats are presented in Appendix 3. UBM Ecological Consultants Pty Ltd Page 29
Flora & Fauna Survey & Ecological Assessments – 35 Water Street Wahroonga The total area within the quadrats surveyed was ~4,400 square metres. This represents 69.3% of the total area of BGHF mapped for the Subject Property (6,350 sq metres) by Smith & Smith (2006). The comparison of the condition of vegetation in each quadrat surveyed in 2007, 2011 and 2012 showed the vegetation contained a higher proportion of exotics in the 2012 survey (see Appendix 3). This occurred in all quadrats except the quadrat 7 pair. In this case, the larger quadrat included additional indigenous vegetation that lowered the proportion of exotics in the upper stratum and ground cover. The condition and extent of the tree canopy was substantially the same throughout the BGHF Habitat Area in each survey period (2007 vs. 2012). The trends in condition of the understorey were however significantly more towards the exotic/weed species. In the small tree stratum (i.e. sub-canopy), there was major increase in projective foliage cover (255 to 470 cover abundance units). The increase in exotic shrub and ground covers was minor (715 to 809 units for shrubs and 750 to 824 cover abundance units for ground covers) (see Table 3.3). The main increase in exotics/weeds was the result of increases in the canopy cover of Large-leaved Privet (Ligustrum lucidum); progressing it from the shrub to the small tree stratum. Ligustrum lucidum also increased its cover in the shrub stratum. The native Pittosporum undulatum increased slightly in canopy cover in the small tree and shrub stratum, also due to growth of its canopy since 2007. English Broom (Genista monspessulana) decreased in cover slightly, probably due to the increased shading by the small trees described above. Indigenous shrubs remained limited to a few scattered individuals. Regeneration comprised two (2) Bleeding Heart Trees (Homalanthus populifolius) and one (1) Rough-barked Applebox (Angophora floribunda) seedlings. In the ground cover stratum, the increase of exotics/weeds was generally small, caused mainly by the spread of Japanese Honeysuckle (Lonicera japonica), English Ivy (Hedera helix), and increases in saplings and seedlings of Small-leaved Privet (Ligustrum sinense), Camphor laurel (Cinnamomum camphora) and Mickey Mouse Bush (Ochna serrulata). These species can be expected to have a major influence on the understorey in the future as they mature to become trees and large shrubs, seed and spread further. Morning Glory (Ipomoea indica) and Wandering Jew (Tradescantia fluminensis) increased significantly in the southern section of the BGHF Habitat Area where the ground was largely bare in 2007 and affected by high nutrient levels from the former poultry run and composting area. There was no significant change in the populations of other major weeds such as Ground Asparagus (Asparagus aethiopicus var. aethiopicus var. densiflorus) and Fishbone Fern (Nephrolepis cordifolia). The native ground covers mainly comprised native grasses such as Weeping Meadow Grass (Microlaena stipoides), Basket Grass (Oplismenus aemulus), and smaller amounts of small forbs such as Common Storksbill (Geranium homeanum). These formed only a minute component of most areas as in 2007. Geranium homeanum appears to have decreased in numbers, possibly due to increased shading by small trees and smothering by exotic vines. Only one (1) large area of native ground cover occurred - in the southern section of the Property, east of the former poultry run and composting area, where the small tree and shrub strata was largely absent and the soil was unaffected by increased nutrient levels (see Figure 1.3). Weeping Meadow Grass (Microlaena UBM Ecological Consultants Pty Ltd Page 30
Page 2 and 3: NOTE BY KU-RING-GAI COUNCIL: ALL RE
Page 4 and 5: Flora & Fauna Survey & Ecological A
Page 90 and 91:
Flora & Fauna Survey & Ecological A
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
show all

Flora & Fauna Survey & Ecological Assessment (pdf. 5MB)

Create successful ePaper yourself

Delete template?

Save as template?