3rd River Conference: Biodiversity and Restoration of alpine rivers 19/05/2015
Introduction history of the invasive Myricaria germanica in New Zealand Antje Wittmann, Norbert Müller & Glenn Stewart
Waimakariri River, 15/04/2014
Tagliamento River, 18/05/2015
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Myricaria germanica in New Zealand
INTRODUCTION Background - braided rivers of NZ most heavily invaded riparian communities in the world (Williams & Wiser 2004)
- 40% native species and 60% naturalised species in NZ‘s braided rivers (Williams & Wiser 2004)
- 163 braided rivers, majority located on South Island (Canterbury region 60%) (Gray & Harding 2007) - M. germanica is characteristic species of braided alpine rivers in Europe and Asia - highly endangered in all European countries - recently introduced to NZ à now regarded as environmental weed (Heenan et al. 1999) - invades open riverbeds à negative impact on native bird species and native plant
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Myricaria germanica in New Zealand
INTRODUCTION Questions Introduction pathways in New Zealand - When, why and how have the first propagules (plants or seeds) of Myricaria germanica been imported in New Zealand? - Where did these plants or seeds come from? History of Naturalization and Invasion in New Zealand - What is the species' current distribution in New Zealand? - When did the species become naturalized (first records)? - Which native and naturalised plants are associated with Myricaria germanica?
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Myricaria germanica in New Zealand
METHODS Literature and Data Acquisiton - literature review M. germanica in Europe à biology, habitat, conservation and restoration - online and database searches - Allan Herbarium (database + physical collection) - Library - consulting with regional experts
Colin Meurk, Landcare Research
A. Wittmann, N. Müller & G. Stewart 2015
Manfred von Tippelskirch, Environment Canterbury
Bill Sykes, Landcare Research
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Myricaria germanica in New Zealand
METHODS Websites - - - -
Weedbusters: http://www.weedbusters.org.nz/ Online Flora: http://nzflora.landcareresearch.co.nz/ New Zealand Virtual Herbarium: http://virtualherbarium.org.nz/home NatureWatch NZ: h"p://naturewatch.org.nz/),
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Myricaria germanica in New Zealand
METHODS Fieldwork - species composition recorded on basis of Braun-Blanquet Scale cover classes
r
+
1
2
3
4
5
cover in %
1
>5
5 – 25
26 – 50
51 – 75
76 - 100
abundance
1
2–5
6 – 50
> 50
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Myricaria germanica in New Zealand
METHODS Fieldwork - questions of distribution and community - vegetation plots à definition of plot size and shape
5 x 5 m quadrat
Defining plot size in field (Waimakariri River, 21/3/2014) A. Wittmann, N. Müller & G. Stewart 2015
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Myricaria germanica in New Zealand
METHODS Overview Fieldwork - 45 plots between March 28 and June 22 - Waimakariri 27 plots; Rakaia 17 plots; Ashburton 1 plot Fig.: Location of vegetation plots within Canterbury
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Myricaria germanica in New Zealand
METHODS Data Analysis - list of all vascular plant species recorded in field à figures and graphs
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Myricaria germanica in New Zealand
METHODS Data Analysis - multivariate analyses à statistic program MVSP - 2 different methods: CCA analysis (canonical correspondence analysis) and cluster analysis
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Myricaria germanica in New Zealand
HABITAT IN NZ Overview - Rakaia largest river in Canterbury à catchment area 2,850 km2, c. 150 km long
http://www.teara.govt.nz/files/p19594gns.jpg A. Wittmann, N. Müller & G. Stewart 2015
http://www.teara.govt.nz/files/ p15593nsil.jpg
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Myricaria germanica in New Zealand
HABITAT IN NZ River catchment areas (from Bowden1983)
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Myricaria germanica in New Zealand
HABITAT IN NZ Climate - strongly influenced by Southern Alps in the west and coastline in the east - rainfall decreases from higher country towards coast - mean annual temperature 10 – 11°C (Sturman 2008) - wamest months Jan. and Febr., July coldest Hydrology - floods common in spring and early summer - flows low in winter (water locked as snow and ice) (GRAY & HARDING 2007) - Rakaia annual mean discharge of 200 m3/s (Gorge Bridge) - Waimakariri à 119 m3/s (Old Highway Bridge) (NCCB & RWB 1986)
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Annual precipitation over Canterbury (from Sturman 2008)
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Myricaria germanica in New Zealand
HABITAT IN NZ Historical Review - earliest characterisation of riverbed formations by Cockayne (1921, 1928, 1958) - 1921: about 56 species - 1928 and 1958: 66 species Unstable riverbeds: - Epilobium-Raoulia Association - frequent flooding
Muehlenbeckia axillaris
Stable riverbeds: - vegetation is an “initial succession which leads, according to the climate of the locality, to tussock- grassland, shrubland or forest as its climax (Cockayne 1928) - low cushions of species of Raoulia spp. - Muehlenbeckia axillaris, dwarf Carmichaelia nana Raoulia australis A. Wittmann, N. Müller & G. Stewart 2015
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Myricaria germanica in New Zealand
HABITAT IN NZ
Epilobium nummulariifolium
Coriaria arborea
Raoulia tenuicaulis
Haloragis erecta
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Myricaria germanica in New Zealand
HABITAT IN NZ History of plant introdution in New Zealand - strongly influenced - first by Polynesian settlers 1,000 yrs ago - by Europeans in the 19th century - vegetation in catchments of rivers especially modified (NCCB & RWB 1986) - areas with frequent flooding generally more vulnerable to invasion by exotic species with weedy strategies (Hood & Naiman 2000; Müller & Okuda 1998; Rejmánek et al. 2013) - burning, felling of native forests, transformation of native grassland/shrubland into pasture and farming - native plants evolved in absence of grazers (slow to recover) (Meurk 2008) - wide range of exotic species introduced - irrigation water taken from rivers
Ulex europaeus A. Wittmann, N. Müller & G. Stewart 2015
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Myricaria germanica in New Zealand
HABITAT IN NZ Plant Introduction in New Zealand - more than 25,000 exotic species introduced within last 200 yrs of settlement - 2,200 plants fully naturalised (Williams & Cameron 2006) à form self-sustaining populations - main introduction pathways:
Agriculture
Horticulture
Forestry
Erosion Control
Accidental
- most species naturalised before 1900 with early European settlers and farming (Williams & Cameron 2006) à exotic grasses for sheep and cattle - farms sheltered with exotic hegdes
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Myricaria germanica in New Zealand
HABITAT IN NZ
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Myricaria germanica in New Zealand
INTRODUCTION OF M. GERMANICA TO NZ Possible introduction pathways of M. germanica 1. Contaminant - introduction through contaminants of other plants (seeds or parts of the plant) - seeds not possible - maybe in combination with other species (Salix spp., Tamarix spp.) 2. Horticulture (deliberately introduced) - NZ nursery catalogues (Duncan & Davies) à no listing - no evidence M. germanica being cultivated in NZ - false tamarisk introduced under different name - mistakenly introduced as Tamarix chinensis à similar characteristics
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Myricaria germanica in New Zealand
INTRODUCTION OF M. GERMANICA TO NZ 3. Soil Stabilisation (deliberatly) - most likely way of introduction - utilisation for bioengineering purposes à erosion control - first record at Willow Island
NZ TOPO MAP 2014 A. Wittmann, N. Müller & G. Stewart 2015
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Myricaria germanica in New Zealand
INTRODUCTION OF M. GERMANICA TO NZ Naturalisation and Conclusion - fully naturalised, classified as environmental weed (invades natural vegetation) - naturalised = reproduce consistently and sustain populations over many life cycles without direct intervention by humans (Rejmánek et al. 2013) - periods of naturalisation: pre-1900, 1900 – 1940, post-1940 (recent introduction) Year of likely Introduction Reason for Introduction Region of Origin st
1 Record Naturalization Distribution Biostatus
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1980s soil stabilisation (accidental) Europe (HEENAN et al. 1999, NZPCN 2014) 1986, Rakaia River 1990s, approx. 1999 Canterbury exotic, fully naturalized
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Myricaria germanica in New Zealand
DISTRIBUTION
Waimakariri
Rakaia Ashburton
Rangitata A. Wittmann, N. Müller & G. Stewart 2015
yellow: records between 1986 and 1999 red: records after 2000
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Myricaria germanica in New Zealand
DISTRIBUTION Waimakariri River - spreads from the highlands (Southern Alps) to the lowlands (Canterbury Plains) - earliest record January 1999 upstream of the Kowai and in the lower reaches
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Myricaria germanica in New Zealand
DISTRIBUTION
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Myricaria germanica in New Zealand
DISTRIBUTION
A. Wittmann, N. Müller & G. Stewart 2015
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Myricaria germanica in New Zealand
DISTRIBUTION
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Myricaria germanica in New Zealand
DISTRIBUTION
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Myricaria germanica in New Zealand
DISTRIBUTION Rakaia River - very first record observed by L. Scott near Willow Island in 1986 - another record near Rakaia Village in 1993
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Myricaria germanica in New Zealand
DISTRIBUTION
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Myricaria germanica in New Zealand
DISTRIBUTION
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Myricaria germanica in New Zealand
DISTRIBUTION Rangitata River - one observation from upper catchment in 2000 - in lower reaches, numerous records downstream motorway bride (DoC 2002) Ashburton River - recent observations by ECan in South Branch Ashburton - considerable population stretches along Alford Forest (North Branch) Selwyn River: - single records for foothills near Gorge (2004 + 2005)
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Myricaria germanica in New Zealand
DISTRIBUTION Ashburton River
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Myricaria germanica in New Zealand
PLANT COMMUNITY IN CANTERBURY Summary Statistics - - - -
total flora of 122 vascular plant species 20 native species (16%) and 102 exotic species (84%) biogeographic origin: 39% from Europe, 27% Asia
45 40 35 30 25 20 15 10 5 0
Europe
Asia
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Africa
North America
South America
Other
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Myricaria germanica in New Zealand
PLANT COMMUNITY IN CANTERBURY Summary Statistics - 29 different plant families and 85 genera (follows Mabberley 2008) 30 indigenous 25
20
15
10
5
0
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exotic
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Myricaria germanica in New Zealand
PLANT COMMUNITY IN CANTERBURY Summary Statistics - life form shows with 44% exotic annual and biennial herbs - 9% native perennial herbs 35 indigenous exotic 30
25
20
15
10
5
0
annual herb
biennial herb
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perennial herb
evergreen perennial deciduous shrub herb
evergreen shrub
deciduous tree
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Myricaria germanica in New Zealand
PLANT COMMUNITY IN CANTERBURY Riverbed Vegetation - 4 species groups - red, blue and yellow cluster: exotic species (lower catchments) - green cluster: native species (correlated to altitude à higher catchment areas)
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Myricaria germanica in New Zealand
PLANT COMMUNITY IN CANTERBURY Riverbed Vegetation - red cluster: 2 subgroups - exotic grasses (Dactylis glomerata, Festuca arundinacea, F. rubra) - exotic shrubs: Ulex europaeus, Cytisus scoparius, Lupinus arboreus - blue cluster: exotic herbs on fine sand (Erodium cicutarium, Lolium perenne and Sonchus arvense) - yellow cluster: exotic herbs on stony ground (most abundant species Rumex acetosella, Plantago lanceolata, Sedum acre, Crepis capillaris, Hypochaeris radicata and Sonchus oleraceus
Festuca arundinacea A. Wittmann, N. Müller & G. Stewart 2015
Sonchus oleraceus
Sedum acre
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Myricaria germanica in New Zealand
PLANT COMMUNITY IN CANTERBURY
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Myricaria germanica in New Zealand
PLANT COMMUNITY IN CANTERBURY
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Myricaria germanica in New Zealand
DISCUSSION AND CONCLUSION - introduction history of false tamarisk cannot be answered unequivocally - more information expected by DNA analysis - colonised major rivers and stretches now from the headwaters to the river mouths - advantage over competitors à light (size), wind-dispersed seed (spread upstream and downstream) - colonizes more habitats in the floodplain than in Europe à less or no competition - only competition are other European species - generally the habitat is similar to natural habitat in Europe à rivers in NZ are almost natural (less regulations) - good conditions for M. germanica
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Myricaria germanica in New Zealand
REFERENCES BOWDEN, M. J. (1983): The Rakaia River and Catchment: A Resource Survey. Volume I. North Canterbury Catchment Board and Regional Water Board, Christchurch COCKAYNE, L. (1921): The Vegetation of New Zealand. Wilhelm Engelmann, Leipzig. 364 p. COCKAYNE, L. (1928): The Vegetation of New Zealand. Second Edition. Wilhelm Engelmann, Leipzig. 456 p. Myricaria germanica in New Zealand 71 COCKAYNE, L. (1958): The Vegetation of New Zealand. Third Edition. Wilhelm Engelmann, Leipzig. 456 p. GRAY, D. & HARDING, J. S. (2007): Braided river ecology. A literature review pf physical habitats and aquatic invertebrate communities. Science for Conservation 279. Department of Conservation, Wellington. 50 p. HEENAN, P. B.; DE LANGE, P. J.; GLENNY, D. S., BREITWIESER, I.; BROWNSEY, P. J.; OGLE, C. C. (1999): Checklist of dicotyledons, gymnosperms, and pteridophytes naturalised or casual in New Zealand: additional records 1997-1998. New Zealand Journal of Botany 37 (4): 629-642 HOOD, W. G. & NAIMAN, R. (2000): Vulnerability of riparian zones to invasion by exotic vascular plants. Plant Ecology 148: 105-114 MABBERLEY, D. J. (2008): Mabberley’s Plant-Book: a portable dictionary of plants, their classification and uses. Third Edition. Cambridge University Press, New York. 1021 p. MEURK, C. (2008): Vegetation of the Canterbury Plains and Downlands. In: WINTERBOURN, M., KNOX, G., BURROWS, C. & MARSDEN, I. (eds.): The Natural History of Canterbury. Canterbury University Press, Christchurch. pp. 197-250
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REFERENCES MÜLLER, N. & OKUDA, S. (1998): Invasion of alien plants in floodplains - a comparison of Europe and Japan. In: STARFINGER, U., EDWARDS, K., KOWARIK, I., & WILLIAMSON, M. (eds.), Plant Invasions: 321-332, Backhuys Publishers, Leiden NCCB & RWB - NORTH CANTERBURY CATCHMENT BOARD & REGIONAL WATER BOARD (1986): Waimakariri River and Catchment Resource Survey. Volume I. The Board, Christchurch N Z P C N - N E W Z E A L A N D P L A N T C O N S E R V AT I O N N E T W O R K ( 2 0 1 4 ) : M y r i c a r i a g e r m a n i c a . U R L : http://www.nzpcn.org.nz/flora_details.aspx?ID=3213 [accessed August 28, 2014] REJMÁNEK, M., RICHARDSON, D. M. & PYŠEK, P. (2013): Plant Invasion and Invasibility of Plant Communities. In: VAN DER MAAREL, E. & FRANKLIN, J. (eds.): Vegetation Ecology. Second Edition. Wiley-Blackwell, Oxford. pp. 389-424 STURMAN, A. (2008): Weather and Climate. In: WINTERBOURN, M., KNOX, G., BURROWS, C. & MARSDEN, I. (eds.): The Natural History of Canterbury. Canterbury University Press, Christchurch. pp. 119-142 WILLIAMS, P. A. & CAMERON, E. K. (2006): Creating Gardens: The Diversity and Progression of European Plant Introductions. p. 33-47 In: ALLEN, R.B. & LEE, W.G. (eds.): Biological Invasions in New Zealand. Ecological Studies 186. Springer, Berlin, Heidelberg WILLIAMS, P. & WISER, S. (2004): Determinants of regional and local patterns in the flora of braided riverbeds in New Zealand. Journal of Biogeography 31. 1355-1372
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