TAXON: Dicksonia squarrosa (G. SCORE: 18.0 RATING: High Risk Forst.) Sw. Taxon: Dicksonia squarrosa (G. Forst.) Sw. Family: Dicksoniaceae Common Name(s): harsh tree fern Synonym(s): Trichomanes squarrosum G. Forst. rough tree fern wheki Assessor: Chuck Chimera Status: Assessor Approved End Date: 11 Sep 2019 WRA Score: 18.0 Designation: H(HPWRA) Rating: High Risk Keywords: Tree Fern, Invades Pastures, Dense Stands, Suckering, Wind-Dispersed Qsn # Question Answer Option Answer 101 Is the species highly domesticated? y=-3, n=0 n 102 Has the species become naturalized where grown? 103 Does the species have weedy races? Species suited to tropical or subtropical climate(s) - If 201 island is primarily wet habitat, then substitute "wet (0-low; 1-intermediate; 2-high) (See Appendix 2) High tropical" for "tropical or subtropical" 202 Quality of climate match data (0-low; 1-intermediate; 2-high) (See Appendix 2) High 203 Broad climate suitability (environmental versatility) y=1, n=0 n Native or naturalized in regions with tropical or 204 y=1, n=0 y subtropical climates Does the species have a history of repeated introductions 205 y=-2, ?=-1, n=0 ? outside its natural range? 301 Naturalized beyond native range y = 1*multiplier (see Appendix 2), n= question 205 y 302 Garden/amenity/disturbance weed n=0, y = 1*multiplier (see Appendix 2) n 303 Agricultural/forestry/horticultural weed n=0, y = 2*multiplier (see Appendix 2) y 304 Environmental weed n=0, y = 2*multiplier (see Appendix 2) n 305 Congeneric weed n=0, y = 1*multiplier (see Appendix 2) y 401 Produces spines, thorns or burrs y=1, n=0 n 402 Allelopathic 403 Parasitic y=1, n=0 n 404 Unpalatable to grazing animals y=1, n=-1 n 405 Toxic to animals y=1, n=0 n 406 Host for recognized pests and pathogens 407 Causes allergies or is otherwise toxic to humans 408 Creates a fire hazard in natural ecosystems y=1, n=0 y 409 Is a shade tolerant plant at some stage of its life cycle y=1, n=0 y Creation Date: 11 Sep 2019 (Dicksonia squarrosa (G. Page 1 of 17 Forst.) Sw.) TAXON: Dicksonia squarrosa (G. SCORE: 18.0 RATING: High Risk Forst.) Sw. Qsn # Question Answer Option Answer Tolerates a wide range of soil conditions (or limestone 410 y=1, n=0 y conditions if not a volcanic island) 411 Climbing or smothering growth habit y=1, n=0 n 412 Forms dense thickets y=1, n=0 y 501 Aquatic y=5, n=0 n 502 Grass y=1, n=0 n 503 Nitrogen fixing woody plant y=1, n=0 n Geophyte (herbaceous with underground storage organs 504 y=1, n=0 n -- bulbs, corms, or tubers) Evidence of substantial reproductive failure in native 601 y=1, n=0 n habitat 602 Produces viable seed y=1, n=-1 y 603 Hybridizes naturally 604 Self-compatible or apomictic y=1, n=-1 y 605 Requires specialist pollinators y=-1, n=0 n 606 Reproduction by vegetative fragmentation y=1, n=-1 y 607 Minimum generative time (years) Propagules likely to be dispersed unintentionally (plants 701 growing in heavily trafficked areas) 702 Propagules dispersed intentionally by people y=1, n=-1 y 703 Propagules likely to disperse as a produce contaminant 704 Propagules adapted to wind dispersal y=1, n=-1 y 705 Propagules water dispersed y=1, n=-1 y 706 Propagules bird dispersed y=1, n=-1 n 707 Propagules dispersed by other animals (externally) y=1, n=-1 n 708 Propagules survive passage through the gut 801 Prolific seed production (>1000/m2) y=1, n=-1 y Evidence that a persistent propagule bank is formed (>1 802 yr) 803 Well controlled by herbicides 804 Tolerates, or benefits from, mutilation, cultivation, or fire y=1, n=-1 y Effective natural enemies present locally (e.g. introduced 805 biocontrol agents) Creation Date: 11 Sep 2019 (Dicksonia squarrosa (G. Page 2 of 17 Forst.) Sw.) TAXON: Dicksonia squarrosa (G. SCORE: 18.0 RATING: High Risk Forst.) Sw. Supporting Data: Qsn # Question Answer 101 Is the species highly domesticated? n Source(s) Notes [No evidence of domestication] "Dicksonia squarrosa occurs Brownsey, P. J. & Perrie, L. R. (2015). Dicksoniaceae. In: throughout the North Island in coastal to montane forest. It grows Breitwieser, I.; Heenan, P. B.; Wilton, A. D. Flora of New from near sea-level to 860 m in the Kaweka and Ruahine ranges. In Zealand ͶFerns and Lycophytes. Fascicle 11. Manaaki the South Island it is largely confined to coastal and lowland sites, Whenua Press, Lincoln but reaches 500 m near Haast, and 900 m at Jordan Stream, Marlborough." 102 Has the species become naturalized where grown? Source(s) Notes WRA Specialist. (2019). Personal Communication NA 103 Does the species have weedy races? Source(s) Notes WRA Specialist. (2019). Personal Communication NA Species suited to tropical or subtropical climate(s) - If 201 island is primarily wet habitat, then substitute "wet High tropical" for "tropical or subtropical" Source(s) Notes "Dicksonia squarrosa occurs throughout the North Island in coastal Brownsey, P. J. & Perrie, L. R. (2015). Dicksoniaceae. In: to montane forest. It grows from near sea-level to 860 m in the Breitwieser, I.; Heenan, P. B.; Wilton, A. D. Flora of New Kaweka and Ruahine ranges. In the South Island it is largely confined Zealand ͶFerns and Lycophytes. Fascicle 11. Manaaki to coastal and lowland sites, but reaches 500 m near Haast, and 900 Whenua Press, Lincoln m at Jordan Stream, Marlborough." [Range extends from subtropical to temperate climates] 202 Quality of climate match data High Source(s) Notes Brownsey, P. J. & Perrie, L. R. (2015). Dicksoniaceae. In: Breitwieser, I.; Heenan, P. B.; Wilton, A. D. Flora of New Zealand ͶFerns and Lycophytes. Fascicle 11. Manaaki Whenua Press, Lincoln 203 Broad climate suitability (environmental versatility) n Source(s) Notes "Altitudinal range: ϬʹϵϬϬm. Dicksonia squarrosa occurs throughout Brownsey, P. J. & Perrie, L. R. (2015). Dicksoniaceae. In: the North Island in coastal to montane forest. It grows from near Breitwieser, I.; Heenan, P. B.; Wilton, A. D. Flora of New sea-level to 860 m in the Kaweka and Ruahine ranges. In the South Zealand ͶFerns and Lycophytes. Fascicle 11. Manaaki Island it is largely confined to coastal and lowland sites, but reaches Whenua Press, Lincoln 500 m near Haast, and 900 m at Jordan Stream, Marlborough." Creation Date: 11 Sep 2019 (Dicksonia squarrosa (G. Page 3 of 17 Forst.) Sw.) TAXON: Dicksonia squarrosa (G. SCORE: 18.0 RATING: High Risk Forst.) Sw. Qsn # Question Answer "Hardiness: Dave's Garden. (2019). Dicksonia Species, Harsh Tree Fern, USDA Zone 9a: to -6.6 °C (20 °F) Rough Tree Fern, Wheki - Dicksonia squarrosa. USDA Zone 9b: to -3.8 °C (25 °F) https://davesgarden.com/guides/pf/go/58592/. [Accessed USDA Zone 10a: to -1.1 °C (30 °F) 11 Sep 2019] USDA Zone 10b: to 1.7 °C (35 °F)" Native or naturalized in regions with tropical or 204 y subtropical climates Source(s) Notes [Range extends from subtropical to temperate climates] "Dicksonia Brownsey, P. J. & Perrie, L. R. (2015). Dicksoniaceae. In: squarrosa occurs throughout the North Island in coastal to montane Breitwieser, I.; Heenan, P. B.; Wilton, A. D. Flora of New forest. It grows from near sea-level to 860 m in the Kaweka and Zealand ͶFerns and Lycophytes. Fascicle 11. Manaaki Ruahine ranges. In the South Island it is largely confined to coastal Whenua Press, Lincoln and lowland sites, but reaches 500 m near Haast, and 900 m at Jordan Stream, Marlborough." Does the species have a history of repeated 205 ? introductions outside its natural range? Source(s) Notes Staples, G.W. & Herbst, D.R. 2005. A Tropical Garden Flora "Dicksonia L'Heritier is a genus of about 25 species from temperate - Plants Cultivated in the Hawaiian Islands and Other South Pacific and tropical America." ͙"At least five species are Tropical Places. Bishop Museum Press, Honolulu, HI grown in Hawai'i," [Includes Dicksonia squarrosa] "This plant has been said to grow in the following regions: Dave's Garden. (2019). Dicksonia Species, Harsh Tree Fern, Eureka, California Rough Tree Fern, Wheki - Dicksonia squarrosa. Mckinleyville, California https://davesgarden.com/guides/pf/go/58592/. [Accessed Thousand Oaks, California 11 Sep 2019] Portland, Oregon" 301 Naturalized beyond native range y Source(s) Notes "We got notification from David Benitez that Dicksonia squarrosa has Parker, J. (2019). BIISC Early Detection Botanist. Pers. been found naturalizing in Volcano Village." ͙"They're definitely Comm. 09 September coming from cultivated plants that somebody felt inclined to stick out there in a tree fern jungle." 302 Garden/amenity/disturbance weed n Source(s) Notes New Zealand Plant Conservation Network. (2014). Flora [Aggressive in gardens] "Dicksonia squarrosa needs room to spread Details - Dicksonia squarrosa. and can become aggressive in some garden situations. This species http://nzpcn.org.nz/flora_details.aspx?ID=1791. often naturally appears in garden situations." [Accessed 10 Sep 2019] A native fern that invades and impacts pastures in New Zealand. See WRA Specialist. (2019). Personal Communication 3.03 303 Agricultural/forestry/horticultural weed y Creation Date: 11 Sep 2019 (Dicksonia squarrosa (G. Page 4 of 17 Forst.) Sw.) TAXON: Dicksonia squarrosa (G. SCORE: 18.0 RATING: High Risk Forst.) Sw. Qsn # Question Answer Source(s) Notes "Of over 12,000 described fern species, about 60 are problematic Arosa, M. L., Ceia, R. S., Quintanilla, L. G., & Ramos, J. A. due to their invasive nature, affecting resource use, human health 2012. The tree fern Dicksonia antarctica invades two and plant communities (Robinson et al. 2010). Of these 60 species, habitats of European conservation priority in São Miguel only two are tree ferns, Dicksonia squarrosa and Sphaeropteris Island, Azores.