DOCSLIB.ORG

Acacia Mearnsii

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Acacia Mearnsii The long-term impact of Acacia mearnsii trees on evaporation, streamflow and groundwater resources TT 505/11 The long-term impact long-term of The TT 505/11 AD Clulow, CS Everson & MB Gush Acacia mearnsii Acacia trees on evaporation, streamflow and groundwater resources and groundwater streamflow on evaporation, trees TT 505/11 THE LONG-TERM IMPACT OF ACACIA MEARNSII TREES ON EVAPORATION, STREAMFLOW AND GROUNDWATER RESOURCES Report to the WATER RESEARCH COMMISSION by A.D. Clulow1, C.S. Everson1, M.B. Gush2 1UKZN, School of Bioresources Engineering and Environmental Hydrology, Pietermaritzburg 2CSIR Natural Resources and the Environment, Pietermaritzburg WRC Report No. TT 505/11 November 2011 i Obtainable from Water Research Commission Private Bag X03 Gezina, 0031 [email protected] The publication of this report emanates from a project titled The long-term impact of Acacia mearnsii trees on evaporation, streamflow and groundwater resources (WRC Project No. K5/1682). DISCLAIMER This report has been reviewed by the Water Research Commission (WRC) and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the WRC, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. ISBN 978-1-4312-0020-3 Printed in the Republic of South Africa ii ACKNOWLEDGEMENTS The research in this project was funded by the Water Research Commission, for whose assistance we are sincerely grateful. The Department of Water Affairs and Forestry are thanked for funding and assistance with drilling boreholes at the site. Mondi are thanked for allowing access to their catchment and for contributions in kind (labour, management operations and data). We also wish to acknowledge contributions made by members of the steering committee: Dr R Dube Water Research Commission (Chairman) Prof J Annandale University of Pretoria Dr M Moodley AquaGreen Consulting Mr J Bosch CSIR, Natural Resources and the Environment Prof P Roberts Forest Industries Association Mr P Gardiner Mondi Forests Mr JM Nel University of the Western Cape Dr A van der Mescht Mangosuthu Technikon Mr AG October University of the Western Cape Prof MJ Savage University of KwaZulu-Natal The following people from the Council of Scientific and Industrial Research (CSIR) provided valuable technical assistance to the trial: Joshua Xaba, Lucas Ngidi, Vivek Naiken and Lelethu Sinuka. Franscois Fourie performed the soil resistivity survey. Bioresources Engineering and Environmental Hydrology at the University of KwaZulu-Natal is acknowledged for their support through assistance from post-graduate students. iii iv TABLE OF CONTENTS ACKNOWLEDGEMENTS .............................................................................. iii TABLE OF CONTENTS .................................................................................. v LIST OF FIGURES ....................................................................................... viii LIST OF TABLES .......................................................................................... xii LIST OF ABBREVIATIONS AND SYMBOLS .............................................. xiii EXECUTIVE SUMMARY ............................................................................... xv 1. INTRODUCTION ................................................................................... 1 1.1 Background ................................................................................ 1 1.2 Experimental Approach .............................................................. 2 1.3 Project Objectives ....................................................................... 3 1.4 History of Research and Funding at Two Streams ..................... 3 2. THE STUDY AREA ............................................................................... 5 2.1 Study Site ................................................................................... 6 3. MATERIALS AND METHODS .............................................................. 8 3.1 Tree Growth ............................................................................... 8 3.2 Rainfall ....................................................................................... 9 3.3 General Climatic Variables ......................................................... 9 3.4 Evaporation Measurement Using Scintillometry ....................... 13 3.5 Computing Total Evaporation ................................................... 19 3.6 Streamflow ............................................................................... 21 3.7 Electrical Resistivity Tomography Study ................................... 22 3.7.1 General description of resistivity method .................... 22 3.7.2 Resistivity data collection and processing ................... 24 3.8 Groundwater Monitoring ........................................................... 25 3.9 Soil Water Dynamics ................................................................ 26 v 3.9.1 Time domain reflectometry .......................................... 26 3.9.2 Probe design ............................................................... 26 3.9.3 Sensor installation ....................................................... 27 3.9.4 Soil physical properties ............................................... 29 3.9.5 Soil physical properties ............................................... 31 3.9.6 Soil survey .................................................................. 31 3.10 Water Balance Modelling .......................................................... 31 3.11 Hydrological Modelling ............................................................. 32 3.11.1 Description of the WAVES model ............................... 32 3.11.1.1 Recent modifications to WAVES ................... 37 3.11.1.2 Suitability for use at Two Streams ................. 37 3.11.2 Description of the ACRU model .................................. 38 3.11.2.1 Suitability for use at Two Streams ................. 40 3.11.3 WAVES catchment configuration ................................ 40 3.11.3.1 Climatic data .................................................. 40 3.11.3.2 Soils information ............................................ 41 3.11.3.3 Land-cover and model setup ......................... 41 3.11.4 ACRU catchment configuration ................................... 41 3.11.4.1 Rainfall and streamflow data ......................... 43 3.11.4.2 Additional climatic data .................................. 44 3.11.4.3 Soils information ............................................ 45 3.11.4.4 Land-cover and model setup ......................... 45 4. RESULTS AND DISCUSSION ........................................................... 46 4.1 Tree Growth ............................................................................. 46 4.1.1 Tree height .................................................................. 46 4.1.2 Leaf area index (LAI) .................................................. 48 4.1.3 Roots .......................................................................... 51 4.2 Rainfall Monitoring .................................................................... 52 4.3 Water-use of Black Wattle ........................................................ 54 4.3.1 Large aperture scintillometer estimates of total evaporation ................................................................. 54 4.3.2 Priestley-Taylor verification ......................................... 61 vi 4.3.3 Reference evaporation and crop factor for Black Wattle .................................................................................... 63 4.4 Streamflow Gauging ................................................................. 67 4.5 Electrical Resistivity Tomography Survey ................................. 70 4.6 Groundwater ............................... Error! Bookmark not defined. 4.7 Soil Water ................................................................................. 73 4.8 Monthly Water Balance ............................................................ 77 4.9 Hydrological Modelling ............................................................. 80 4.9.1 Soil water modelling .................................................... 80 4.9.2 Streamflow modelling .................................................. 84 5. FINAL DISCUSSION AND CONCLUSION ......................................... 86 6. REFERENCES .................................................................................... 91 Appendix A. The two weekly intervals used to calculate effective height of the LAS beam above the canopy. ................................... 99 Appendix B. Borehole logs. ..................................................................... 102 vii LIST OF FIGURES Figure 2.1. Location of the Seven Oaks district in the KwaZulu-Natal midlands. .................................................................................... 5 Figure 2.2. Location of instruments in the Two Streams catchment. The large aperture scintillometer (LAS) transect is shown with the transmitter on the west and receiver on the east of the catchment. The automatic weather station (AWS) site included the area where the soil water measurements took place. The five borehole sites were labelled according to their position in the plantation. ............................................................................. 7 Figure 3.1. Original automatic weather station at Two Streams. ................ 11 Figure 3.2. The automatic weather station
Load more

Recommended publications
  • Wattles of the City of Whittlesea
    Wattles of the City of Whittlesea PROTECTING BIODIVERSITY ON PRIVATE LAND SERIES Wattles of the City of Whittlesea Over a dozen species of wattle are indigenous to the City of Whittlesea and many other wattle species are commonly grown in gardens. Most of the indigenous species are commonly found in the forested hills and the native forests in the northern parts of the municipality, with some species persisting along country roadsides, in smaller reserves and along creeks. Wattles are truly amazing • Wattles have multiple uses for Australian plants indigenous peoples, with most species used for food, medicine • There are more wattle species than and/or tools. any other plant genus in Australia • Wattle seeds have very hard coats (over 1000 species and subspecies). which mean they can survive in the • Wattles, like peas, fix nitrogen in ground for decades, waiting for a the soil, making them excellent cool fire to stimulate germination. for developing gardens and in • Australia’s floral emblem is a wattle: revegetation projects. Golden Wattle (Acacia pycnantha) • Many species of insects (including and this is one of Whittlesea’s local some butterflies) breed only on species specific species of wattles, making • In Victoria there is at least one them a central focus of biodiversity. wattle species in flower at all times • Wattle seeds and the insects of the year. In the Whittlesea attracted to wattle flowers are an area, there is an indigenous wattle important food source for most bird in flower from February to early species including Black Cockatoos December. and honeyeaters. Caterpillars of the Imperial Blue Butterfly are only found on wattles RB 3 Basic terminology • ‘Wattle’ = Acacia Wattle is the common name and Acacia the scientific name for this well-known group of similar / related species.
    [Show full text]
  • Acacia Mearnsii) in the Tsomo Valley in Eastern Cape: Consequences on the Water Recharge and Soil Dynamics (An Ongoing Study)
    Grassroots: Newsletter of the Grassland Society of Southern Africa ▪ May 2009 ▪ Vol. 9 ▪ No. 2 Impact of the removal of black wattle (Acacia mearnsii) in the Tsomo Valley in Eastern Cape: Consequences on the water recharge and soil dynamics (an ongoing study) HPM Moyo, S Dube and AO Fatunbi Department of Livestock and Pasture Sciences, University of Fort Hare Email: [email protected] lack wattle (Acacia mearnsii) (Galatowitsch and Richardson is a fast growing leguminous 2004). Acacia mearnsii ranks first in B (nitrogen fixing) tree and it is water use among invasive species, often used as a commercial source using 25% of the total amount, and of tannins and a source of fire wood is estimated to reduce mean annual for local communities (DWAF 1997). runoff by 7% in South Africa (Dye Riparian ecosystems are widely re- and Jarmain 2004). The invasive garded as being highly prone to in- ability of this species is partly due to vasion by alien plants, especially A. its ability to produce large numbers mearnsii, largely because of their of long-lived seeds (which may be dynamic hydrology, nutrient levels, triggered to germinate by fires) and and ability to disperse propagules the development of a large crown (Galatowitsch and Richardson that shades other vegetation (Nyoka 2004). Disturbing native vegetation 2003). also causes invasion as this often Acacia mearnsii threatens na- prepares a seed bed for invader spe- tive habitats by competing with in- cies (DWAF 1997). Native fynbos digenous vegetation, replacing grass tree species lack mycorrhyzal asso- communities; reducing native biodi- ciates and therefore are less efficient versity and increasing water loss at nutrient uptake (Smita 1998), from the riparian zones (Nyoka leading to them being out-competed 2003).
    [Show full text]
  • Henderson, L. (2007). Invasive, Naturalized and Casual Alien Plants in Southern Africa
    Bothalia 37,2: 215–248 (2007) Invasive, naturalized and casual alien plants in southern Africa: a sum- mary based on the Southern African Plant Invaders Atlas (SAPIA) L. HENDERSON* Keywords: biomes, casual alien plants, invasive plants, Lesotho, naturalized plants, roadside surveys, SAPIA mapping project, South Africa, Swaziland ABSTRACT The primary objective of this publication is to provide an overview of the species identity, invasion status, geographical extent, and abundance of alien plants in South Africa, Swaziland and Lesotho, based on fi eld records from 1979 to the end of 2000. The dataset is all the species records for the study area in the Southern African Plant Invaders Atlas (SAPIA) database during this time period. A total of 548 naturalized and casual alien plant species were catalogued and invasion was recorded almost throughout the study area. Most invasion, in terms of both species numbers and total species abundance, was recorded along the southern, southwestern and eastern coastal belts and in the adjacent interior. This area includes the whole of the Fynbos and Forest Biomes, and the moister eastern parts of the Grassland and Savanna Biomes. This study reinforces previous studies that the Fynbos Biome is the most extensively invaded vegetation type in South Africa but it also shows that parts of Savanna and Grassland are as heavily invaded as parts of the Fynbos. The Fabaceae is prominent in all biomes and Acacia with 17 listed species, accounts for a very large proportion of all invasion. Acacia mearnsii was by far the most prominent invasive species in the study area, followed by A.
    [Show full text]
  • ACACIA Miller, Gard
    Flora of China 10: 55–59. 2010. 31. ACACIA Miller, Gard. Dict. Abr., ed. 4, [25]. 1754, nom. cons. 金合欢属 jin he huan shu Acaciella Britton & Rose; Racosperma Martius; Senegalia Rafinesque; Vachellia Wight & Arnott. Morphological characters and geographic distribution are the same as those of the tribe. The genus is treated here sensu lato, including the African, American, Asian, and Australian species. Acacia senegal (Linnaeus) Willdenow and A. nilotica (Linnaeus) Delile were treated in FRPS (39: 28, 30. 1988) but are not treated here because they are only rarely cultivated in China. 1a. Leaves reduced to phyllodes. 2a. Phyllodes 10–20 × 1.5–6 cm; inflorescence a spike ...................................................................................... 1. A. auriculiformis 2b. Phyllodes 6–10 × 0.4–1 cm; inflorescence a head ................................................................................................... 2. A. confusa 1b. Leaves bipinnate. 3a. Flowers in racemes or spikes. 4a. Trees armed; pinnae 10–30 pairs ....................................................................................................................... 7. A. catechu 4b. Shrubs unarmed; pinnae 5–15 pairs. 5a. Racemes 2–5 cm; midveins of leaflets close to upper margin ............................................................ 8. A. yunnanensis 5b. Racemes shorter than 2 cm; midveins of leaflets subcentral ........................................................................ 5. A. glauca 3b. Flowers in heads, then rearranged in panicles. 6a.
    [Show full text]
  • An Assessment of the Impacts of Invasive Australian Wattle Species on Grazing Provision and Livestock Production in South Africa
    AN ASSESSMENT OF THE IMPACTS OF INVASIVE AUSTRALIAN WATTLE SPECIES ON GRAZING PROVISION AND LIVESTOCK PRODUCTION IN SOUTH AFRICA by Thozamile Steve Yapi Thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Ecology, Faculty of AgriSciences, Stellenbosch University Supervisor: Dr Patrick O’Farrell Co-supervisors: Prof. Karen Esler and Dr Luthando Dziba December 2013 Stellenbosch University http://scholar.sun.ac.za DECLARATION By submitting this thesis electronically, I declare that the entirety of the work contained therein is my own, original work, that I am the sole author thereof and that I have not previously in its entirety or in part submitted it for obtaining any qualification. Thozamile Steve Yapi Full names and surname December 2013 Date Copyright © 2013 Stellenbosch University All rights reserved i Stellenbosch University http://scholar.sun.ac.za ABSTRACT I investigated the impacts of the invasive wattle species (Acacia mearnsii, A. dealbata, A. decurrens), on the ecological function and productivity of rangelands in South Africa and their ability to sustain livestock production. More specifically, this study set out to: (1) assess grazing areas at a national scale; (2) identify evidence of progressive impacts of these species on livestock production across a selection of magisterial districts; (3) determine the effects of A. mearnsii density on growth form dominance of indigenous plant species, and highlight how this translates into impacts in forage quality and quantity; (4) determine the effects of A. mearnsii invasion on soil resources and conditions (key determinates of ecological function) required to support grazing production; and finally (5) determine to effects that clearing operations have had on the provision of grazing resources.
    [Show full text]
  • Adoption, Use and Perception of Australian Acacias Around the World
    Diversity and Distributions, (Diversity Distrib.) (2011) 17, 822–836 S BIODIVERSITY Adoption, use and perception of PECIAL ISSUE RESEARCH Australian acacias around the world Christian A. Kull1*, Charlie M. Shackleton2, Peter J. Cunningham3, Catherine Ducatillon4, Jean-Marc Dufour-Dror5, Karen J. Esler6, James B. Friday7, Anto´nio C. Gouveia8, A. R. Griffin9, Elizabete Marchante8, Stephen J. :H Midgley10, Anı´bal Pauchard11, Haripriya Rangan1, David M. Richardson12, Tony Rinaudo13, Jacques Tassin14, Lauren S. Urgenson15, Graham P. von Maltitz16, Rafael D. Zenni17 and Matthew J. Zylstra6 UMAN - MEDIATED INTRODUCTIONS OF 1School of Geography and Environmental Science, ABSTRACT Monash University, Melbourne, Australia, 2Department of Environmental Science, Rhodes Aim To examine the different uses and perceptions of introduced Australian University, Grahamstown, South Africa, 3Sowing acacias (wattles; Acacia subgenus Phyllodineae) by rural households and Seeds of Change in the Sahel Project, SIM, communities. Maradi, Niger Republic, 4INRA, Jardin Thuret, Antibes, France, 5Environmental Policy Center, Location Eighteen landscape-scale case studies around the world, in Vietnam, Jerusalem Institute for Israel Studies, Jerusalem, India, Re´union, Madagascar, South Africa, Congo, Niger, Ethiopia, Israel, France, Israel, 6Department of Conservation Ecology and Portugal, Brazil, Chile, Dominican Republic and Hawai‘i. A Journal of Conservation Biogeography Entomology and Centre for Invasion Biology, Stellenbosch University, South Africa, 7University
    [Show full text]
  • Variation in Basic Wood Density and Percentage Heartwood in Temperate Australian Acacia Species
    126 Wood of temperate Australian acacias Variation in basic wood density and percentage heartwood in temperate Australian Acacia species S.D. Searle1,2 and J.V. Owen3 1PO Box 6201, O’Connor, ACT 2602, Australia 2Email: [email protected] 3CSIRO Forestry and Forest Products, PO Box E4008, Kingston, ACT 2604, Australia Revised manuscript received 15 March 2005 Summary 530–598 kg m–3 (Hillis 1997) and 550–850 kg m–3 (Dobson and Feely 2002). Species, provenance and within-tree variation in basic wood density and percentage heartwood were assessed in 18 tree-form A few Acacia species and provenance trials planted in southern Acacia species/subspecies (40 provenances) and Eucalyptus nitens Australia in the 1990s have been assessed for wood density (either (one provenance) from southern Australia. The 229 trees from basic, air-dry or green) at a particular age and the sampling strategy two 8-y-old trials in the Australian Capital Territory were has been described (Barbour 2000; Clark 2001). One of the destructively sampled. difficulties in comparing such density data, when they are available, is that they have frequently been collected using different Whole-tree, volume-weighted basic wood densities for the Acacia procedures for within-tree and within-population sampling species were between 568 and 771 kg m–3 and provenance means (Balodis 1994; Downes et al. 1997; Ilic et al. 2000). were in the range 520–778 kg m–3. Percentage heartwood, sampled at 20% of tree height, ranged between 2.4 and 43.8% for species Basic wood density influences both the paper-making process and 0.0 and 44.1% for provenances.
    [Show full text]
  • Synoptic Overview of Exotic Acacia, Senegalia and Vachellia (Caesalpinioideae, Mimosoid Clade, Fabaceae) in Egypt
    plants Article Synoptic Overview of Exotic Acacia, Senegalia and Vachellia (Caesalpinioideae, Mimosoid Clade, Fabaceae) in Egypt Rania A. Hassan * and Rim S. Hamdy Botany and Microbiology Department, Faculty of Science, Cairo University, Giza 12613, Egypt; [email protected] * Correspondence: [email protected] Abstract: For the first time, an updated checklist of Acacia, Senegalia and Vachellia species in Egypt is provided, focusing on the exotic species. Taking into consideration the retypification of genus Acacia ratified at the Melbourne International Botanical Congress (IBC, 2011), a process of reclassification has taken place worldwide in recent years. The review of Acacia and its segregates in Egypt became necessary in light of the available information cited in classical works during the last century. In Egypt, various taxa formerly placed in Acacia s.l., have been transferred to Acacia s.s., Acaciella, Senegalia, Parasenegalia and Vachellia. The present study is a contribution towards clarifying the nomenclatural status of all recorded species of Acacia and its segregate genera. This study recorded 144 taxa (125 species and 19 infraspecific taxa). Only 14 taxa (four species and 10 infraspecific taxa) are indigenous to Egypt (included now under Senegalia and Vachellia). The other 130 taxa had been introduced to Egypt during the last century. Out of the 130 taxa, 79 taxa have been recorded in literature. The focus of this study is the remaining 51 exotic taxa that have been traced as living species in Egyptian gardens or as herbarium specimens in Egyptian herbaria. The studied exotic taxa are accommodated under Acacia s.s. (24 taxa), Senegalia (14 taxa) and Vachellia (13 taxa).
    [Show full text]
  • Newsletter: September 2016 Ot
    NEWSLETTER: SEPTEMBER 2016 OT Dam – Birds & Fungi 4th July OT Dam, part of the Arthurs Seat State Park, has never been a happy hunting ground for birding for us (one time our total bird count was two Black Ducks, which immediately flew away), but we decided to give it another go after several years. The vegetation is largely eucalypt woodland, with the usual E. radiata, E. ovata and E. obliqua. It often seems to me that where the trees are dominated by E. obliqua (Messmate) there are very few birds. This seemed to be true here as it is at Woods Reserve at Teurong. Although bird numbers were considerably higher than we had recorded before, they were still pretty low – low enough that we got distracted with the abundant fungi. For what it's worth, our bird list is given here. Bird List for OT Dam 4th July 2016 Wedge-tailed Eagle Eastern Yellow Robin White-throated Treecreeper Golden Whistler Brown Thornbill Grey Shrike-thrush Little Wattlebird Grey Butcherbird White-throated Tree-creeper. Photo: Lee Denis Yellow-faced Honeyeater Mistletoebird Cortinarius archeri – with an equally striking purple cap, White-eared Honeyeater Silvereye also mycorrhizal on Eucalypts. Old specimens are brown. New Holland Honeyeater Amanita xanthocephala – red cap with yellow flecks, which are the remains of the veil – also mycorrhizal on By far the highlight of the day was an extended close Eucalypts. encounter with a White-throated Treecreeper, which Amanita ochrophylla – a white cap over a thick stem with a persisted in exploring low on the trunks of trees within bulbous base – also mycorrhizal.
    [Show full text]
  • The Genus Acacia As Invader: the Characteristic Case of Acacia Dealbata Link in Europe Paula Lorenzo, Luís González, Manuel J
    The genus Acacia as invader: the characteristic case of Acacia dealbata Link in Europe Paula Lorenzo, Luís González, Manuel J. Reigosa To cite this version: Paula Lorenzo, Luís González, Manuel J. Reigosa. The genus Acacia as invader: the characteristic case of Acacia dealbata Link in Europe. Annals of Forest Science, Springer Nature (since 2011)/EDP Science (until 2010), 2010, 67 (1), 10.1051/forest/2009082. hal-00883584 HAL Id: hal-00883584 https://hal.archives-ouvertes.fr/hal-00883584 Submitted on 1 Jan 2010 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Ann. For. Sci. 67 (2010) 101 Available online at: c INRA, EDP Sciences, 2009 www.afs-journal.org DOI: 10.1051/forest/2009082 Review article The genus Acacia as invader: the characteristic case of Acacia dealbata Link in Europe Paula Lorenzo,LuísGonzalez´ *,ManuelJ.Reigosa Departamento de Bioloxía Vexetal e Ciencia do Solo, Facultade Bioloxía, Universidade de Vigo, As Lagoas Marcosende 36310 Vigo, Spain (Received 20 May 2009; accepted 7 July 2009) Keywords: Abstract Acacia dealbata / • We review current knowledge about the biology of the genus Acacia,andAcacia dealbata Link biodiversity / (silver wattle) in particular, as an invader in Europe, focusing on (i) the biology of the genus Acacia; biological attributes / (ii) biological attributes that are important for the invasiveness of the genus and A.
    [Show full text]
  • Warrandyte's Wattles the Flowers of Warrandyte's Wattles Vary in Colour from Creamy-Yellow to Deep Gold
    Warrandyte's Wattles The flowers of Warrandyte's wattles vary in colour from creamy-yellow to deep gold. Only two species have true adult leaves (Black Wattle and Silver Wattle). A ll others develop phyllodes; flattened leaf-stalks that look like and function like leaves. Most flower from late winter to spring. They can be found in a wide range of vegetation communities, from the riverbanks to the ridges. Several other species of wattle from other parts of Australia grow in the Warrandyte bush. These are garden Gold-dust Wattle Acacia acinacea escapes that have become environmental BlackWattle Acacia mearnsii weeds.You can help prevent their spread by only planting wattles indigenous to our area. Gold-dust Wattle Acacia acinacea Open spreading shrub to 1.5m. July-Oct. Small ovate to oblong phyllodes on arching branches, profuse flowers along stems. Thin-leaf Wattle Acacia aculeatissima Prostrate or low sprawling shrub to 30cm. Thin-leafWattle Acacia aculeatissima June-Dec. Prickly phyllodes usually point down stems at odd angles, flowers along stems. Silver Wattle Acacia dealbata Tree to 15m.July-Nov. Blueish-green ferny leaves, dense flower sprays followed by purplish seed pods. B la c k w o o d Acacia melanoxylon Spreading Wattle Acacia genistifolia Open erect shrub to 2.5m.Aug-Oct. and occasionally in autumn Silver W attle Acacia dealbata Long narrow prickly phyllodes, pale flowers along stems. Lightwood Acacia implexa Small tree to 8m. Dec-Mar. Long dark green sickle-shaped phyllodes, flowers in sprays, develops corky bark with age. BlackWattle Acacia mearnsii Tree to 10m. Sept-Dec.
    [Show full text]
  • The Acacia Wood Rot Fungus, Cylindrobasidium Leave
    Stumpout®: a fungal inoculant to prevent resprouting of cut stumps of black wattle (Acacia mearnsii) & golden wattle (A. pycnantha) The Acacia Wood Rot Fungus, Cylindrobasidium leave Alan Wood & Khaya Ntushelo Plant Protection Research Institute, Private Bag X5017, Stellenbosch, 7599 Background The fungus Cylindrobasidium laeve was isolated from dead black wattle (Acacia mearnsii) stumps near George and Joubertina in the Western and Eastern Cape, and is indigenous to South Africa. The fungus was then developed into Stumpout®, a user- friendly and affordable treatment to prevent cut stumps of black wattle and golden wattle (A. pycnatha) from resprouting after felling. This prevents multi-stemmed trees from developing and which are more difficult and costlier to control. Environmental impact In addition to its user-friendliness and affordability, Stumpout® is an environmentally friendly product. It has none of the negative environmental impacts of chemical herbicides, especially those used in a diesel carrier. It is particularly suitable for use in areas close to water sources where herbicide application can lead to contamination of the water. Cylindrobasidium laeve is not a pathogen (an organism that causes disease) but rather is a saprophytic (feeding on dead matter) wood rotting fungus. In the natural environment it is one of many fungi involved in the decomposition of wood. It is therefore unlikely to spread to any close-by living trees and attack them, not even pruned fruit trees. Formulation The fungus is grown on sterile wood discs of A. mearnsii at 18°C. When enough spores have been produced, they are brushed off the discs and into sterile mineral oil, an inert carrier.
    [Show full text]