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Myriophyllum rubricaule Valk. & Duist. sp. nov. urn:lsid:ipni.org:names:77299815-1 Fig. 1 Myriophyllum robustum auct. non Hook.f. Molecular Ecology Resources 13: 21–31 (Ghahramanzadeh et al. 2013). Myriophyllum brasiliense auct. non Cambess.: plants in trade. Myriophyllum sp. trade name ‘brasiliensis’: Beringen R. 2020. — Pot R. et al. 2021. — Q-bank Invasive Plants. 2019–2021. — EPPO-Q-bank. 2022. Diagnosis Herba perennis aquatica vel paludigena. Folia omnia verticillata pectinata. Flores unisexuales, solae plantae femininae culturaeque cognitus. Flores intra axillas foliorum solitarii. Planta valde similaris Myriophyllo aquatico, sed caules foliaque modice, caules purpurei et folia emergentia virida. Flores feminei subrosei. Etymology The species epithet is based on the purplish red color of the stem. Type material NETHERLANDS • Grashoek, Roomweg 85, 5985 NS, Golf course Kapelkeshof; 51°22.0′ N, 5°56.5′ E; herbarium specimen; 13 Jul. 2009; fl; J.L.C.H. van Valkenburg & J. Hoogveld 3495; holotype: L!; isotypes: WAGPD[WAG0453615]!, A!, BM!, BR!, MO!, NSW!; GenBank nos: MZ399148 (trnK3), MZ399140 (trnH-psbA), MZ399132 (rbcL), MZ399123 (matK), MZ401380 (ITS); SRA: ERR6000190. Additional specimens examined NETHERLANDS • Wageningen, open air pond at PD; herbarium specimen; originally from Wageningen, Garden Centre d’Oude Tol; 14 Jun. 2007; fl; J.L.C.H. van Valkenburg 3298; J.L.C.H. van Valkenburg det.; WAGPD[WAG0453612]; GenBank nos: MZ399146 (trnK3), MZ399138 (trnH-psbA), MZ399130 (rbcL), MZ399121 (matK), MZ401378 (ITS); SRA: ERR6000191 • Vinkeveen, Aquaflora Vinkeveen, Ter Aase Zuwe, near junction main road Vinkeveen to Wilnis; herbarium specimen; cultivated at Wageningen, open air pond at PD, originally from Vinkeveen, collected 5 Apr. 2007; 9 Jul. 2007; fl; J.L.C.H. van Valkenburg 3314; J.L.C.H. van Valkenburg det.; WAGPD [WAG0453613] • herbarium specimen; grown by ‘ Simon van der Velde Waterplanten BV’, Albert van ‘t Hartweg 1, Bleiswijk; 30 Jul. 2007; J.L.C.H. van Valkenburg 3342; J.L.C.H. van Valkenburg det.; WAGPD [WAG0453614]; GenBank nos: MZ399147 (trnK3), MZ399139 (trnH-psbA), MZ399131 (rbcL), MZ399122 (matK), MZ401377 (ITS); SRA: ERR6000192 • Wageningen, Garden Centre d’Oude Tol; herbarium specimen; culta the Netherlands; 11 Apr. 2009; J.L.C.H. van Valkenburg 3472; J.L.C.H. van Valkenburg det.; L [L 0767219; L 0909277]; GenBank no.: JX100590 (trnH-psbA) • Wageningen, Geertjesweg 15, Plant Protection Service; herbarium specimen; culta, first received 1 May 2009 from Stoffels International BV, Maalbekerweg 14, 5951 NT, Belfeld, the Netherlands; 11 Sep. 2009; fl; J.L.C.H. van Valkenburg 3510; J.L.C.H. van Valkenburg det.; L [L 0767220; L 0909323]; GenBank nos: JX100591 (trnH-psbA), JX100753 (rbcL) • Wageningen, greenhouse Plant Protection Service; herbarium specimen; culta from plant obtained at garden centre; 28 Jul. 2011; J.L.C.H. van Valkenburg 3648; J.L.C.H. van Valkenburg det.; WAGPD [WAG0453609]; GenBank nos: MZ399149 (trnK3), MZ399158 (trnH-psbA), MZ399153 (rbcL), MZ399124 (matK), MZ401372 (ITS); SRA: ERR6000195 • Hoogeveen, Kinholt; 52°43.34′ N, 6°26.00′ E; herbarium specimen; 5 Nov. 2018; J.L.C.H. van Valkenburg 3971; J.L.C.H. van Valkenburg det.; WAGPD [WAG0453559]; GenBank nos: MZ399159 (trnH-psbA), MZ399154 (rbcL) • Steenwijk, Het Eemter; 52°47.415′ N, 6°08.840′ E; herbarium specimen; 8 Sep. 2020; J.L.C.H. van Valkenburg 4116; J.L.C.H. van Valkenburg det.; WAG [WAG.1971556], WAGPD [WAG0452369]; GenBank nos: MZ399160 (trnH-psbA), MZ399155 (rbcL), MZ401381 (ITS) • Hattem, Palmstraat; 52°27.768′ N, 6°04.428′ E; herbarium specimen; 8 Sep. 2020; J.L.C.H. van Valkenburg 4117; J.L.C.H. van Valkenburg det.; WAG [WAG.1971558], WAGPD [WAG0452378]; GenBank nos: MZ399161 (trnH-psbA), MZ399156 (rbcL), MZ401382 (ITS) • Klazienaveen; 52°44.580′ N, 7°00.615′ E; herbarium specimen; 7 Oct. 2020; J.L.C.H. van Valkenburg 4118; J.L.C.H. van Valkenburg det.; WAGPD [WAG0452243]; GenBank nos: MZ399150 (trnK3), MZ399141 (trnH-psbA), MZ399133 (rbcL), MZ399125 (matK), MZ401375 (ITS); SRA: ERR6000193 • Wageningen, greenhouse NVWA; herbarium specimen; culta, origin garden center more than 8 years ago; 8 Oct. 2020; J.L.C.H. van Valkenburg 4119; J.L.C.H. van Valkenburg det.; WAGPD [WAG0452240]; GenBank nos: MZ399151 (trnK3), MZ399142 (trnH-psbA), MZ399134 (rbcL), MZ399126 (matK), MZ401376 (ITS); SRA: ERR6000194. HUNGARY • Borsod-Abaúj-Zemplén, Kács; 47°57.44′ N, 20°37.00′ E; herbarium specimen; 20 Sep. 2019; A. Mesterházy s.n.; J.L.C.H. van Valkenburg det.; WAGPD [WAG0452409]; GenBank nos: MZ399157 (trnH-psbA), MZ399152 (rbcL). Description Dioecious amphibic or aquatic herb. Stem unbranched or with up to 6 branches per 20 cm, often rooting at submerged and lower emerged nodes; submerged part green to tinged red-brown and internodes 10–50 mm long; emerged part red or purplish red and internodes 3–25 mm long. Hydathodes few at base of submerged leaves, many at base of emerged leaves, ca 1 mm long, filiform, pale or reddish brown. Leaves in whorls of 4 or 5, pinnatifid with pinnae placed opposite and/or alternate. Submerged leaves 10–25(–50) × 3–10 mm, olive green or turning pale to dark reddish brown; pinnae 12–21, 3–14(–30) × 0.1–0.2 mm. Emerged leaves (7–)10–25 × 3–8 mm, bright green to bluish green, not glaucous, sometimes tinged red brown or pinnae red-tipped; pinnae (5–)7–21, 2.3–9 × 0.15–0.3(–0.5) mm. Flowers solitary in the axils of the emerged leaves, only female known, tinged pink. Pedicel 0.3–0.5 mm long. Bracteoles 2 at basis of pedicel, 0.5–1 × 0.1 mm, with 1–3 alternate and filiform lobes. Sepals 4, erecto-patent to reflexed, 0.5–0.7 × 0.2–0.3 mm, margin remotely fimbriate. Petals absent. Stamens absent. Ovary 4-sulcate, with 4 styles with feathery and more or less inrolled stigmas. Fruits unknown. Amphibic herb with pinnate leaves in whorls of 4 or 5, only known from female plants and (escapes from) horticulture. Differs from M. aquaticum in its generally more modest dimensions, the stems being purplish red, the emergent leaves being green to bluish green and not glaucous (i.e., leaves without waxy coating) and the female flowers being pinkish (Fig. 1). Distribution Origin unknown. Known from cultivation (Netherlands, Belgium) and as escapes from cultivation since 2018 in the Netherlands (Hoogeveen, Steenwijk, Hattem, Klazienaveen) and Belgium (Maasmechelen, Houthalen-Helchteren, Brugge, Gent, Beauraing, Waimes; all confirmed from photographs at waarnemingen.be), and at least since 2019 in Hungary (Kács). It is unclear whether the observations in Belgium before 2018 (in retrospect the first observation dates from 2012; see waarnemingen.be records 70176185 and 95286205) refer to escapes or planted material. Note If grown in particularly nutrient rich and/or high light conditions plants develop much bigger submerged leaves (e.g., Valkenburg 3298 and 4116 WAGPD). Similar species Because both the submerged and emergent leaves are whorled, pectinate and not much different in length, and the inflorescence is emergent, the species fits in section Pectinatum M.L.Moody & D.H.Les. This section includes M. aquaticum and M. mattogrossense Hoehne (Moody & Les 2010). Myriophyllum aquaticum differs from M. rubricaule sp. nov. in having green stems only turning red when grown as a potted plant or in unfavorable conditions, but never purplish red, with leaves in whorls of 4–6, submerged leaves 25–45 mm long and green or red brown, emerged leaves 25–35 mm long and bluish green glaucous (i.e., with a waxy coating that can be rubbed of), and white flowers. Myriophyllum mattogrossense has green stems, small, globular, sessile glands on leaves and stems, submerged leaves 10–35 mm wide, and bisexual flowers (Crow & Ritter 1999). While performing the DNA barcoding study of M. aquaticum (Ghahramanzadeh et al. 2013), we initially thought that the plants described here as a new species belonged to M. robustum. This is a species resembling M. aquaticum with similar emergent pectinate leaves and solitary axillary flowers. However, M. robustum is described as having hermaphrodite flowers whereas M. aquaticum is dioecious (Orchard 1980). Shortly after our paper was published, plants of M. robustum were received from New Zealand and were grown in a greenhouse. The cultivated plants had more robust erect emergent stems that were pink in the upper part, and subglaucous leaves that were oblong in outline with an acute tip. Surprisingly, the plants produced only female flowers in the greenhouse (Valkenburg 3739 WAGPD). Grown outdoors in a mesocosm in later years, the plants first produced female flowers, a row of hermaphrodite flowers and then, distally, male flowers (Valkenburg 3853 WAGPD). Distinguishing molecular features of Myriophyllum rubricaule sp. nov. As described above, M. rubricaule sp. nov. is morphologically distinguishable from M. aquaticum. Moody & Les (2010) described two specimens, M. sp. ‘red 1’ and M. sp. ‘red 2’, that were morphologically and genetically related to M. aquaticum. We made a molecular comparison of M. rubricaule, M. aquaticum, M. sp. ‘red 1’ and M. sp. ‘red 2’ using the same molecular markers (Moody & Les 2010), namely the nuclear locus ITS (partial 18S, ITS1, 5.8S, ITS2, partial 28S), and the chloroplast loci trnK3 and matK to find out how M. sp. ‘red 1’ and M. sp. ‘red 2’ relate to M. rubricaule (Figs 2–3). We included Myriophyllum heterophyllum Michx. and Laurembergia tetrandra (Schott) Kanitz as more distantly related species within the Haloragaceae in this comparison. Based on ITS (Fig. 2), all M. rubricaule sp. nov. specimens showed 100% sequence similarity. Myriophyllum sp. ‘red 1’ was most similar to M. rubricaule sharing 98.62% sequence identity. We only observed differences in the ITS1 sequence (38–42delCCCCG and 87delG). Interestingly, the specimens of M. aquaticum group with M. sp. ‘red 2’, albeit with a relatively low confidence value, sharing 96.27% and 93.65% identity with M. rubricaule, respectively. The trnK3 and matK loci were extracted from the sequence data and subsequently concatenated, before tree generation. Similarly to ITS, the trnK3-matK sequences were identical for all samples of M. rubricaule sp. nov. (Fig. 3). Intriguingly, the M. sp. ‘red 2’ and M. aquaticum JL 8405 trnK3-matK loci were identical to M. rubricaule. Myriophyllum aquaticum JvV 3494 and TP 3977 showed 99.88% similarity with M. rubricaule and M. sp. ‘red 2’ with only two single nucleotide polymorphisms (SNPs; T32A and T1243A). Myriophyllum sp. ‘red 1’ differs on 10 positions with M. aquaticum, M. rubricaule and M. sp. ‘red 2’ sharing 99.63% similarity. Finally, we compared two other well-known chloroplast loci, rbcL and trnH-psbA, to identify more distinguishing molecular features between M. aquaticum and M. rubricaule sp. nov. We incorporated previously described sanger sequences (Ghahramanzadeh et al. 2013) as well as newly generated sanger and Illumina sequences in the comparison (Supp. file 1 and 2). For trnH-psbA, all 12 specimens of M. rubricaule were identical to each other. Seven out of eight M. aquaticum were identical, for M. aquaticum JL 8405 we observed one SNP (G230A) (Supp. file 3). However, for two samples of M. aquaticum not all sanger data could be resolved resulting in two ambiguities: M188A for M. aquaticum JvV 3329 and K255T for M. aquaticum HD 426. A clear distinction was observed towards the 5’-end of the trnH-psbA intergenic spacer (nucleotides #237–292) where 13 SNPs were identified between the specimens of M. aquaticum and M. rubricaule resulting in approximately 96% similarity. Interestingly, we did not find any differences between M. aquaticum and M. rubricaule rbcL sequences (Supp. file 4). Even the distantly related plant species L. tetrandra shared 97.29% of rbcL identity. In contrast, for trnH-psbA, only a ~ 69–73% identity score was observed between L. tetrandra and M. rubricaule and M. aquaticum., Published as part of Van Valkenburg, Johan L. C. H., Boer, Edu & Raaymakers, Tom M., 2022, Myriophyllum rubricaule sp. nov., a M. aquaticum look-alike only known in cultivation, pp. 1-15 in European Journal of Taxonomy 828 on pages 4-8, DOI: 10.5852/ejt.2022.828.1847, http://zenodo.org/record/6802479, {"references":["Ghahramanzadeh R., Esselink G., Kodde L. P., Duistermaat H., van Valkenburg J. L. C. H., Marashi S. H., Smulders M. J. M. & van de Wiel C. C. M. 2013. Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding. Molecular Ecology Resources 13: 21 - 31. https: // doi. org / 10.1111 / 1755 - 0998.12020","Moody M. L. & Les D. H. 2010. Systematics of the aquatic angiosperm genus Myriophyllum (Haloragaceae). Systematic Botany 35: 121 - 139. https: // doi. org / 10.1600 / 036364410790862470","Crow G. E. & Ritter N. P. 1999. Myriophyllum mattogrossense (Haloragaceae), a rare lowland watermilfoil new to Bolivia. Rhodora 101: 28 - 39.","Orchard A. E. 1980. Myriophyllum (Haloragaceae) in Australasia. I. New Zealand: A revision of the genus and a synopsis of the family. Brunonia 2: 247 - 287. https: // doi. org / 10.1071 / BRU 9790247"]}

Van Valkenburg, Johan L.C.H., Boer, Edu, Raaymakers, Tom M. (2022): Myriophyllum rubricaule sp. nov., a M. aquaticum look-alike only known in cultivation. European Journal of Taxonomy 828: 1-15, DOI: https://doi.org/10.5852/ejt.2022.828.1847, URL: http://dx.doi.org/10.5852/ejt.2022.828.1847

Slide of Euphresco project 2016-A-184 'Identification protocols for analysis of aquatic plants imports (IPAAPI)'

Les plantes aquatiques invasives connaissent une expansion grandissante en Europe et les Pays-Bas ne sont pas épargnés. À travers les exemples d'expérimentations sur deux espèces invasives, Cabomba caroliniana et Ludwigia peploides, il est intéressant de voir comment les institutions locales envisagent le problème et comment s'organise la gestion des proliférations.

Aim Large trees (d.b.h.≥70 cm) store large amounts of biomass. Several studies suggest that large trees may be vulnerable to changing climate, potentially leading to declining forest biomass storage. Here we determine the importance of large trees for tropical forest biomass storage and explore which intrinsic (species trait) and extrinsic (environment) variables are associated with the density of large trees and forest biomass at continental and pan-tropical scales. Location Pan-tropical. Methods Aboveground biomass (AGB) was calculated for 120 intact lowland moist forest locations. Linear regression was used to calculate variation in AGB explained by the density of large trees. Akaike information criterion weights (AICc-wi) were used to calculate averaged correlation coefficients for all possible multiple regression models between AGB/density of large trees and environmental and species trait variables correcting for spatial autocorrelation. Results Density of large trees explained c. 70% of the variation in pan-tropical AGB and was also responsible for significantly lower AGB in Neotropical [287.8 (mean)±105.0 (SD) Mg ha -1 versus Palaeotropical forests (Africa 418.3±91.8 Mg ha-1; Asia 393.3±109.3 Mg ha-1). Pan-tropical variation in density of large trees and AGB was associated with soil coarseness (negative), soil fertility (positive), community wood density (positive) and dominance of wind dispersed species (positive), temperature in the coldest month (negative), temperature in the warmest month (negative) and rainfall in the wettest month (positive), but results were not always consistent among continents. Main conclusions Density of large trees and AGB were significantly associated with climatic variables, indicating that climate change will affect tropical forest biomass storage. Species trait composition will interact with these future biomass changes as they are also affected by a warmer climate. Given the importance of large trees for variation in AGB across the tropics, and their sensitivity to climate change, we emphasize the need for in-depth analyses of the community dynamics of large trees.

Julius-Kühn-Archiv, Nr. 455 (2016): HALT Ambrosia - final project report and general publication of project findings

Invasive non-native species (INS) are species which have moved outside of their natural range, usually with the aid of humans, and are causing environmental or economic damage. At a global level, INS are believed to be one of the most significant causes behind loss of biodiversity – second only to habitat destruction. Their economic impact is also substantial. A recent study by the European Environment Agency (EEA) estimated that INS cost Europe in the region of 12 billion Euros every year. Despite the severe damage these species are causing, there is little in the way of a coordinated effort to reduce their impact and spread across Europe.Over recent years a number of projects have sought to improve the management of INS across the Two Seas region, by bringing together research institutes, universities, local government, land managers, businesses and other relevant stakeholders to form cross-border partnerships. RINSE (Reducing the Impact of Non-native Species In Europe) focussed primarily on INS withinfreshwater and terrestrial habitats. It undertook a broad range of activities in order to share best practice across the region, develop new ways to manage INS, improve the capacity of local organisations to manage INS, prioritise INS already present in the region for action and identify species likely to cause problems in the near future. The MEMO (Mnemiopsis Ecology, Modellingand Observation) partnership was composed of experts in marine INS and focussed on one species in particular – the American comb jelly Mnemiopsis leidyi. This invasive jellyfish-like species was accidentally introduced to the Two Seas region and has since spread along the coasts of northern France, Belgium and the Netherlands. MEMO undertook a range of activitiesto assess awareness and perceptions of the jelly amongst key stakeholder groups and to increase our scientific knowledge on this species. Invexo aimed to improve the management of four of the most damaging INS in Belgium and the Netherlands. The project used field trials to improve control and eradication methods and developed an early warning system for high risk INSin the project area. Discussions between partners from the RINSE, MEMO and Invexo projects indicated that added value could be created through the formation of a ‘cluster’ project, bringing together the expertise and theexperiences gained from each of the three projects. As a consequence, SEFINS (Safeguarding the Environment From Invasive Non-native Species) was established in January 2014. Since then, the partnership has held a number of constructive workshops and meetings on the topic of INS. It was clear that despite each project working on different species in different habitats, therewas a large degree of crossover. A number of key themes emerged, which the partnership agreed require further work in order to allow EU Member States to meet the new requirements of the upcoming European Regulation on Invasive Species:1) Knowledge transfer, training and advice2) Data and inventories3) Risk management and impact assessments4) Citizen science and awareness raisingThis publication uses these key themes as chapters, describing in more detail the activities carried out by RINSE, MEMO and Invexo within these areas. Key outputs are summarised, outlining the significant progress made by the SEFINS partners and their previous projects towards the effective management of INS across the Two Seas area. However, there is clearly much work still to be done – this publication will also look forwards, outlining where we believe work on INS should focus in the immediate future.

Invasive non-native species (INS) are species which have moved outside of their natural range, usually with the aid of humans, and are causing environmental or economic damage. At a global level, INS are believed to be one of the most significant causes behind loss of biodiversity – second only to habitat destruction. Their economic impact is also substantial. A recent study by the European Environment Agency (EEA) estimated that INS cost Europe in the region of 12 billion Euros every year. Despite the severe damage these species are causing, there is little in the way of a coordinated effort to reduce their impact and spread across Europe.Over recent years a number of projects have sought to improve the management of INS across the Two Seas region, by bringing together research institutes, universities, local government, land managers, businesses and other relevant stakeholders to form cross-border partnerships. RINSE (Reducing the Impact of Non-native Species In Europe) focussed primarily on INS withinfreshwater and terrestrial habitats. It undertook a broad range of activities in order to share best practice across the region, develop new ways to manage INS, improve the capacity of local organisations to manage INS, prioritise INS already present in the region for action and identify species likely to cause problems in the near future. The MEMO (Mnemiopsis Ecology, Modellingand Observation) partnership was composed of experts in marine INS and focussed on one species in particular – the American comb jelly Mnemiopsis leidyi. This invasive jellyfish-like species was accidentally introduced to the Two Seas region and has since spread along the coasts of northern France, Belgium and the Netherlands. MEMO undertook a range of activitiesto assess awareness and perceptions of the jelly amongst key stakeholder groups and to increase our scientific knowledge on this species. Invexo aimed to improve the management of four of the most damaging INS in Belgium and the Netherlands. The project used field trials to improve control and eradication methods and developed an early warning system for high risk INSin the project area. Discussions between partners from the RINSE, MEMO and Invexo projects indicated that added value could be created through the formation of a ‘cluster’ project, bringing together the expertise and theexperiences gained from each of the three projects. As a consequence, SEFINS (Safeguarding the Environment From Invasive Non-native Species) was established in January 2014. Since then, the partnership has held a number of constructive workshops and meetings on the topic of INS. It was clear that despite each project working on different species in different habitats, therewas a large degree of crossover. A number of key themes emerged, which the partnership agreed require further work in order to allow EU Member States to meet the new requirements of the upcoming European Regulation on Invasive Species:1) Knowledge transfer, training and advice2) Data and inventories3) Risk management and impact assessments4) Citizen science and awareness raisingThis publication uses these key themes as chapters, describing in more detail the activities carried out by RINSE, MEMO and Invexo within these areas. Key outputs are summarised, outlining the significant progress made by the SEFINS partners and their previous projects towards the effective management of INS across the Two Seas area. However, there is clearly much work still to be done – this publication will also look forwards, outlining where we believe work on INS should focus in the immediate future.

Several methods were deployed simultaneously to control, if not eradicate, the highly invasive Crassula helmsii (Australian swamp stonecrop, New Zealand pigmy weed) in a newly created shallow pond adjoining the heath and moorland pools of the Dutch nature reserve Huis ter Heide. Measures included mechanical removal of top soil after draining, followed by extensive covering of pond margins with non-transparent foil, regular manual removal of washed-up plants, and addition of non-toxic dyes. The latter aimed to reduce compensation depth sufficiently to prevent submerged growth below the foil-covered area. Treatment with a mixture of soluble red and black dyes (DyoFix®), commercialized for the control of aquatic weeds and phytoplankton, started in January 2013. Five further additions followed in the course of this year to make up for losses and (starting from July) to increase concentration. Biomass of submerged vegetation was recorded prior to dye treatment (October 2012) and again in October 2013. Total biomass was substantially higher on the second occasion, mainly due to the continued increase of Crassula which became dominant throughout the pond. The abundance of Eleocharis acicularis did not change markedly, whilst Potamogeton pusillus decreased. Vegetation height increased slightly and the number of macrophyte taxa remained similar. Measurement of photosynthetically active radiation at different water depths showed that prolonged light limitation was unlikely to have occurred even in the deepest part of the pond, despite the use of considerably higher doses of dye than recommended. Consequently, the lack of a negative response was no surprise.Although pond morphology and water-level changes complicated application in this particular case, effective control of Crassula helmsii by ‘shading’ with dyes appears unlikely given the extreme growth plasticity of this species.The Huis ter Heide demonstration project is part of the EU co-funded Interreg 2Seas project RINSE (Reducing the Impact of Non-Native Species in Europe; www.rinse-europe.eu), which seeks to improve awareness of the threats posed by INNS, and the methods to address them.

Globally, Invasive Alien Species (IAS) are considered to be one of the major threats to native biodiversity, with the World Conservation Union (IUCN) citing their impacts as ‘immense, insidious, and usually irreversible’. It is estimated that 11% of the c. 12,000 alien species in Europe are invasive, causing environmental, economic and social damage; and it is reasonable to expect that the rate of biological invasions into Europe will increase in the coming years. In order to assess the current position regarding IAS in Europe and to determine the issues that were deemed to be most important or critical regarding these damaging species, the international Freshwater Invasives - Networking for Strategy (FINS) conference was convened in Ireland in April 2013. Delegates from throughout Europe and invited speakers from around the world were brought together for the conference. These comprised academics, applied scientists, policy makers, politicians, practitioners and representative stakeholder groups. A horizon scanning and issue prioritization approach was used by in excess of 100 expert delegates in a workshop setting to elucidate the Top 20 IAS issues in Europe. These issues do not focus solely on freshwater habitats and taxa but relate also to marine and terrestrial situations. The Top 20 issues that resulted represent a tool for IAS management and should also be used to support policy makers as they prepare European IAS legislation. © 2014 The Author(s).

This report contains the result of a research project on four invasive aquatic macrophytes, Cabomba caroliniana (Fanwort), Hydrocotyle ranunculoides (Floating pennywort) , Myriophyllum aquaticum (Parrott’s feather) and Ludwigia grandiflora (Water primrose). The collaborative project was intended to generate a prototype decision support system for optimising control measures for these species, considered to be the four most troublesome invasive alien aquatic weeds at present in the UK and NL. A further reason for selecting these species is that they are widely sold in the horticultural trade and are therefore the number of invaded sites is likely to increase in the short term., Scientific report of the Euphresco funded project 'Decision Support Systems for ControL of Alien Invasive Macrophytes' (DeCLAIM)

Aim Our aim was to evaluate the extent to which we can predict and map tree alpha diversity across broad spatial scales either by using climate and remote sensing data or by exploiting spatial autocorrelation patterns. Location Tropical rain forest, West Africa and Atlantic Central Africa. Methods Alpha diversity estimates were compiled for trees with diameter at breast height ≥10cm in 573 inventory plots. Linear regression (ordinary least squares, OLS) and random forest (RF) statistical techniques were used to project alpha diversity estimates at unsampled locations using climate data and remote sensing data [Moderate Resolution Imaging Spectroradiometer (MODIS), normalized difference vegetation index (NDVI), Quick Scatterometer (QSCAT), tree cover, elevation]. The prediction reliabilities of OLS and RF models were evaluated using a novel approach and compared to that of a kriging model based on geographic location alone. Results The predictive power of the kriging model was comparable to that of OLS and RF models based on climatic and remote sensing data. The three models provided congruent predictions of alpha diversity in well-sampled areas but not in poorly inventoried locations. The reliability of the predictions of all three models declined markedly with distance from points with inventory data, becoming very low at distances >50km. According to inventory data, Atlantic Central African forests display a higher mean alpha diversity than do West African forests. Main conclusions The lower tree alpha diversity in West Africa than in Atlantic Central Africa may reflect a richer regional species pool in the latter. Our results emphasize and illustrate the need to test model predictions in a spatially explicit manner. Good OLS or RF model predictions from inventory data at short distance largely result from the strong spatial autocorrelation displayed by both the alpha diversity and the predictive variables rather than necessarily from causal relationships. Our results suggest that alpha diversity is driven by history rather than by the contemporary environment. Given the low predictive power of models, we call for a major effort to broaden the geographical extent and intensity of forest assessments to expand our knowledge of African rain forest diversity. © 2011 Blackwell Publishing Ltd.

Slide of the Euphresco project 'Decision support systems for control of alien invasive macrophytes' (DeCLAIM), Project funded through the Euphresco network

Identifying and explaining regional differences in tropical forest dynamics, structure, diversity, and composition are critical for anticipating region-specific responses to global environmental change. Floristic classifications are of fundamental importance for these efforts. Here we provide a global tropical forest classification that is explicitly based on community evolutionary similarity, resulting in identification of five major tropical forest regions and their relationships: (i) Indo-Pacific, (ii) Subtropical, (iii) African, (iv) American, and (v) Dry forests. African and American forests are grouped, reflecting their former western Gondwanan connection, while Indo-Pacific forests range from eastern Africa and Madagascar to Australia and the Pacific. The connection between northern-hemisphere Asian and American forests is confirmed, while Dry forests are identified as a single tropical biome.Knowledge about the biogeographic affinities of the world’s tropical forests helps to better understand regional differences in forest structure, diversity, composition, and dynamics. Such understanding will enable anticipation of region-specific responses to global environmental change. Modern phylogenies, in combination with broad coverage of species inventory data, now allow for global biogeographic analyses that take species evolutionary distance into account. Here we present a classification of the world’s tropical forests based on their phylogenetic similarity. We identify five principal floristic regions and their floristic relationships: (i) Indo-Pacific, (ii) Subtropical, (iii) African, (iv) American, and (v) Dry forests. Our results do not support the traditional neo- versus paleotropical forest division but instead separate the combined American and African forests from their Indo-Pacific counterparts. We also find indications for the existence of a global dry forest region, with representatives in America, Africa, Madagascar, and India. Additionally, a northern-hemisphere Subtropical forest region was identified with representatives in Asia and America, providing support for a link between Asian and American northern-hemisphere forests.