Risk Assessment Robinia Pseudoacacia L
Total Page:16
File Type:pdf, Size:1020Kb
Risk assessment Robinia pseudoacacia L. Naamloos-2 1 15-03-13 08:10 © Naturalis Biodiversity Center, Leiden March 2013 Naamloos-2 2 15-03-13 08:10 Risk assessment Robinia pseudoacacia L. E. Boer March 2012 Naamloos-2 1 15-03-13 08:10 Naamloos-2 2 15-03-13 08:10 Table of contents 1. Introduction — 5 2. Robinia pseudoacacia: description, ecology and history — 6 2.1. Description — 6 2.2. Ecology — 6 3. Risk assessment — 8 3.1. Entry — 8 3.2. Establishment — 8 3.3. Spread — 8 3.4. Endangered areas — 9 3.5. Impact — 10 3.5.1. Ecological impact — 10 3.5.2. Economic impact — 10 3.5.3. Social impact — 11 4. Risk management — 12 4.1. Prevention of deliberate planting — 12 4.2. Prevention of dispersal — 12 4.3. Eradication and control — 12 4.4. Conclusions — 13 5. References — 14 Annex 1 Risk assessment scores using the ISEIA protocol — 16 This report was commissioned by the Invasive Alien Species Team of the Netherlands Food and Consumer Product Safety Authority. Table of contents 3 Naamloos-2 3 15-03-13 08:10 4 Risk assessment Robinia pseudoacacia L. Naamloos-2 4 15-03-13 08:10 1. Introduction Exotic, invasive plant species have a negative impact on biodiversity, economy and/or public health. For this reason the Invasive Alien Species Team of the Netherlands Food and Consumer Product Safety Authority has requested a risk assessment for Robinia pseudoacacia. The current risk assessment will focus on the situation in the Netherlands and discuss the following subjects: • Probability of entry • Probability of establishment in the Netherlands • Probability of spread • Identification of endangered areas based on the results of the three previous subjects • Impact of Robinia pseudoacacia in respect to ecological, economical and public health aspects • Management options to eradicate the species • Management options to control further spread and reduce impact. This report is based on published literature, either in print or in the internet. Introduction 5 Naamloos-2 5 15-03-13 08:10 2. Robinia pseudoacacia: description, ecology and history 2.1. Description 2.2. Ecology Robinia pseudoacacia is a deciduous tree belonging Robinia pseudoacacia is a native to eastern North to the Fabaceae family. It is a fast-growing tree America. It is a pioneer species, which is replaced up to 15-30 m in height, up to 120 cm in diameter, already after 20-30 years through successional bark of saplings smooth and green, mature tree processes. It is found on a wide variety of sites but with dark brown and deeply furrowed bark, with does best on rich moist limestone soils and soils flat-topped ridges, up to 4 cm thick, stem forking without pronounced subsoil development. Its native in ascending branches and horizontal and more range is classified as humid and climatic conditions crooked-growing branches; branches glabrous, are: January average daily temperatures: -4° to 7°C, branches of seedling and sprouts with stout, paired August average daily temperatures: 18° to 27°C, stipular spines, buds almost invisible (sunken in mean length of frost-free period, 150 to 210 days tissue) and terminal bud absent. Leaves alternate, and normal annual total precipitation: 1020-1830 20-30 cm long, imparipinnate with (7-)9-25 leaflets, mm, elevation is up to 1040 m a.s.l. (Huntley, 1990) leaflets oval to rounded, leaflet tip mucronate, dark Black locust is very sensitive to poorly drained or green above and pale green beneath. Inflorescences compact plastic soils. Excessively dry sites are drooping clusters, about 15 cm long, arising from also poor for the species. As a species with pioneer leaf axils near the tip of new shoots, flowers up to characteristics it is intolerant of shade and compe- 2 cm long, white with a yellow blotch on the upper- tition of herbaceous vegetation (Huntley, 1990). most petal, fragrant. Fruits: pods, 5-10 cm long, flat, smooth and glabrous, with 4-8 dark, 3-5 mm long seeds (van der Meijden, 2005; Wieseler, 2005; Stone, 2009; de Koning et al., 2009). Species closely resembling Robinia pseudoacacia (Black locust) are Robinia viscosa (with pink flowers) and Robinia hispida (with rose-purple flo- wers); all three Robinia species are native to the Appalachians. These two resembling species, when used in cultivation, may share Black locust’s invasive tendencies (Wieseler, 2005). 6 Risk assessment Robinia pseudoacacia L. Naamloos-2 6 15-03-13 08:10 Figure 1 Winter aspect of Robinia pseudoacacia. Description, ecology and history 7 Naamloos-2 7 15-03-13 08:10 3. Risk assessment 3.1. Entry 3.2. Establishment The first introduction ofRobinia pseudoacacia in Eu- Robinia pseudoacacia is found naturalized in the rope from North America dates back to the year 1601. following countries (Cabi, 2012; Başnou, 2006; see The tree was brought to France (Muller, 2004). It was Figure 3): planted as an ornamental and for timber production. • Europe: Albania, Austria, Belarus, Belgium, In the Netherlands the first record is of 1847, by 1879 Bosnia-Hercegovina, Bulgaria, Croatia, Cyprus, the tree is said to be common and naturalized near Czech Republic, Denmark, Finland, France, Den Bosch (van der Ham, unpublished). Today it is Germany, Greece, Hungary, Ireland, Italy, Latvia, still the most widely planted American tree species Liechtenstein, Lithuania, Malta, Moldova, in Europe (Başnou, 2006). Seedling production for the Netherlands, Poland, Portugal, Romania, European market is concentrated in Italy as seed- Russian Federation, Serbia, Slovakia, Spain, lings develop more rapidly in the warmer climate Sweden, Switzerland, Ukraine, United Kingdom when compared to northern Europe (Moraal, 2008). • Asia: Afghanistan, Bhutan, China, India, Israel, Japan, Jordan, North Korea, South Korea, Myan- Planting of Robinia pseudoacacia in the USA has mar, Nepal, Pakistan, Turkey receded due to the locust borer Megacyllene • Africa: Botswana, Kenya, Namibia, Réunion, South robiniae (Forster) (Coleoptera: Cerambycidae). Africa, Zimbabwe This borer is often the cause of rapid population • North America: Canada, Mexico, USA (native and declines in plantation settings (Stone, 2009). Borer introduced) attack is often followed by fungal attack, of which • South America: Argentina, Chile heart rot by Fomes rimosus is the most common • Oceania: Australia, New Zealand. (Converse, 1984). In Europe, it is the most widely distributed alien tree species (Lambdon, et al, 2008). More recently Black locust is planted for a wide range of objectives viz. erosion control, reclamation In the Netherlands, Robinia pseudoacacia is of drastically disturbed sites, windbreaks, nurse found throughout the country, see figure 4 with an crops, amelioration of sites, honey production, increased occurrence in the northern part of the and ornamental use (Muller, 2004). In Germany, country since 1980 (FLORON & NHN, 2012). 14.000 ha of Robinia has been planted (Starfinger & The probability of establishment in the Netherlands Kowarik, 2003) and in Hungary 20% of the forested is high, and has occurred widely. area is planted with Robinia providing 25% of the annual timber cut (Redei, 1997 in: CABI, 2012). By 1984 there were worldwide over 1 million hectares 3.3. Spread of Robinia pseudoacacia plantations (Sabo, 2000). Robinia pseudoacacia is mainly distributed by man and planted for a variety of purposes. Planted and Plantation for timber production has recently at- established trees can spread through seeds or, tracted a lot of attention, as the timber quality can more importantly, by means of sprouting. compete with that of imported tropical hardwoods; a silvicultural and economical analysis revealed Most natural reproduction of Black locust is that production of sawn timber with a rotation of 25 vegetative by means of root suckering and stump years would be economically feasible in the Nether- sprouting. Root suckers originate from endogenous lands (Oosterbaan et al. 2002). Currently, an estima- adventitious buds in the roots, primarily where ted 800 ha of plantations of Robinia pseudoacacia branch roots emerge from older roots. Sprouts arise exist in the Netherlands (Dirkse et al., 2006). from dormant buds at the root crown, or on the The probability of entry in the Netherlands is very lower portion of the trunk. Physical damage to roots high. and stems (top damage, cutting, burning) 8 Risk assessment Robinia pseudoacacia L. Naamloos-2 8 15-03-13 08:10 Figure 2 White, fragrant flowers in drooping clusters. Figure 5 Sprouts with heavy thorns. Figure 3 World distribution Figure 4 Distribution in the Netherlands increases suckering and sprouting. Root suckering tion, hindering seedling establishment. Seedlings and stump sprouting forms groves (or clones) of also exhibit juvenile growth with rapid growth and trees interconnected by a common fibrous root sturdy thorns (Stone, 2009; Bossard et al., 2000). system. Lateral spread of these groves in a study in Ohio, USA, valued 1-3 m per year. In its native range In the USA Robinia pseudoacacia is abundant in Black locust roots may spread laterally up to 50 m. logged stands and responds immediately through Sprouts exhibit juvenile growth characterized by vigorous sprouting, rapid growth and increased rapid growth and heavy thorns. More suckers are abundance (Stone, 2009). produced in full sun, open areas and sandy loam soil than in shade, dense vegetation and heavy soils The probability of rapid spread by seed is low as (Wieseler, 2005; Converse, 1984; Stone, 2009). seeds have a low viability and are dispersed over short distances only. Spread by extension through Seed production starts at the age of six and good root suckers is slow, likely under 1 m/year. seed crops are produced every 1-3 years. The distance over which seeds are dispersed is limited. Seed production is abundant, but seeds rarely 3.4. Endangered areas germinate. This is due to seed coat impermeability In some cases nitrogen fixation can facilitate later- and high light requirements for germination.