The Dirty Dozen

Wilding conifers (10 species) alters our landscape, takes up large amounts of water from the water table and prevents regeneration of native species.

Buddleia forms dense stands in wide range of habitats. In riverbeds it can alter water flow, causing silt build-up and flooding.

Woolly nightshade produces toxins that poison the soil and inhibits regeneration.

Darwin's barberry replaces shrubland and regenerating forest.

Wild ginger grows from rhizomes. Dense beds replace all other species, and are shallow rooted, so when they become heavy with rain they can slip on steep sites and streambanks, causing erosion.

English ivy is a both a ground cover and climbing vine. It smothers and kills all plants from ground level to canopy, and prevents the establishment of native plant seedlings.

Wandering willie is also a ground cover. Like ivy it smothers the ground, preventing native seedlings from establishing.

Climbing asparagus smothers forest floor and understorey to 4 m, preventing the establishment of native plant seedlings and growth of established species. It can ringbark and kill soft-barked shrubs and trees.

Old man's beard smothers and kills all plants to the highest canopy, and prevents the establishment of native plant seedlings.

Moth plant germinates inside established forest, and smothers and kills plants up into the canopy, preventing the establishment of native plant species.

Banana passionfruit (4 species) smothers canopy, preventing recruitment.

Japanese honeysuckle climbs over and smothers most plants from ground to medium canopy. It can cause canopy collapse and subsequent invasion of grasses or ground vines.

Spartina (2 species) is a grass species found in the inter-tidal zone. It traps sediment, raising the level of the ground above the high tide mark and destroying the inter-tidal zone and habitat. It can reduce large estuaries and shallow harbours to thin drains surrounded by rough pasture, resulting in an immense loss of biodiversity.

Also see the project check list at https://inaturalist.nz/lists/421274-The-Dirty-Dozens-Check-List?rank=species menos ↑