早熟禾(Poa annua)被列为有害生物，对农作物有害，种子是可能的污染物(USDA-ARSU 2008)。早熟禾(Poa annua)是亚南极的先锋物种，它率先拓殖到冰碛土(冰河碎片)留下去冰川化的土地。但是一般认为，它只是原生演替的次要角色(Frenot等人, 1998)。此外，目前尚未确定此物种是否有入侵性。Frenot等人(2001)描述此物种是归化种，广泛地分布在原生社群，显然不会导致原生社群强烈的变化。斯科特 & 柯克帕特里克(2005)测试是否有任何证据显示早熟禾(Poa annua)可能会取代本地物种，结果并没有发现直接证据。早熟禾(Poa annua)通常需要不断的生物性干扰，经由践踏提供裸露的地面，或经由授粉和动物蜕皮提供养分，成为亚南极地区的主要植被。亚南极地区人类活动的增加，可能会增加此物种的蔓延。早熟禾(Poa annua)和其它入侵物种之间的相互作用可能很大。驯鹿对亚南极岛屿的植被有重大影响，并可能助长早熟禾(Poa annua)散播(Frenot等人, 1998)。
King George Is. (Antarctic) (Antarctica)
生态系统变化: Poa annua was noted for the first time in natural communities in summer 2005 (M. Olech Unpub. Data). However, at South Georgia and Arctowski oasis it seems to be rather persistent than invasive, and has restricted distribution in the colonisation area (M. Olech Unpub. Data, McIntosh and Walton 2000, in Chwedorzewska 2008).
Macquarie Is. (sub-Antarctic) (Australia)
与其它入侵物种相互作用: The rabbits (Oryctolagus cuniculus) on Macquarie Island have caused severe vegetational damage which has allowed the further spread of Poa annua and Cerastium holosteoides (Costin & Moore 1960, in Walton 1975).
Kerguelen Is. (sub-Antarctic) (French Southern Territories)
与其它入侵物种相互作用: Ten reindeer (Rangifer tarandus) from Sweden were introduced to Kerguelen in 1955 and increased to a population of circa 2000 individuals by 1972. Reindeer have major impacts on the vegetation of the sub-Antarctic Islands and may encourage the dispersal and establishment of the more resilient invasive grass, Poa annua (Frenot et al. 2005).
Sheep, rabbit and reindeer grazing has persisted for many years on Kerguelen. A recent report suggests that of the introduced plant species only P. annua, Poa pratensis, Sagina procumbens and Cerastium holosteoides seem to be taking advantage of the biotic disturbance and spreading to new areas (Young 1971, in Walton 1975).
降低本地生物多样性: If climate changes continue, with increases in temperatures and decreases in rainfall, the spread of P. annua is predicted to increase with negative consequences for indigenous plant communities (Frenot et al. 2005).
Heard Is. (sub-Antarctic) (Heard Island and McDonald Islands (sub-Antarctic))
竞争: Scott & Kirkpatrick (2005) tested whether there is any indication that P. annua might displace native species. Their data set provided no direct evidence that P. annua displaces other plant species in undisturbed vegetation.
Inaccessible Is. (sub-Antarctic) (Saint Helena)
生态系统变化: Nitrogen rich soils apparently favour species such as Poa annua, while adversely affecting the vigour of indigenous ferns (Huntley 1971, in Dean et al. 1994).
Sth. Georgia Is. (sub-Antarctic) (Sth. Georgia and Sth. Sandwich Iss (sub-Antarctic))
与其它入侵物种相互作用: Reindeer (Rangifer tarandus) have major impacts on the vegetation of the sub-Antarctic Islands and may encourage the dispersal and establishment of the more resilient invasive grass, Poa annua (Frenot et al. 2005).
Distribution of P. annua, Cerastium fontanum and Taraxacum officinale may have been assisted by reindeer through seed transport in droppings and on hair and hooves (Moen & MacAlister 1994). P. annua is heavily grazed by reindeer, especially mid-late summer (February to March) (Pratt & Smith 1982).
生态系统变化: Poa annua has formed replacement swards (see Kightley and Smith 1976) where some native species have been eradicated.
降低本地生物多样性: If climate changes continue, with increases in temperatures and decreases in rainfall, the spread of P. annua is predicted to increase with negative consequences for indigenous plant communities.