Planning the action for success � Avoid seed dispersion: anticipate the flowering, follow prevailing wind direction� Respect sensitive periods and areas for fauna species� Fit the period and meteorology with the application of herbicide� Contingency plan for the use of herbicide (preventive measures and monitoring)� Others: tidal regime, accessibility, etc.

Elimination methodologies� Mechanical + Chemical*: adult specimens (> 50-75 cm) and resprouts (from other elimination campaigns).� Manual: young specimens (< 50-75 cm). Small hand tools used to remove completely the root system if needed.� No pruning waste management required (no rooting risk)

*Herbicide mixture: 50% Glyfos Envision® glyphosate (45%), 50% fuel oil (B type)

Life+ Project Estuaries of the Basque Country: control and elimination of Baccharis halimifolia L. in Urdaibai

Estela BetetaA(estela.beteta@ihobe.net), Leire OrejaB, Amador PrietoC & Marta RozasD

AIhobe, Public Environmental Management Corporation; BAranzadi Society of Sciences; CNatural Science Society of Sestao; DBiodiversity and Environment Participation Directorate, Basque Government.

� Selected elimination methodologies are effective, but it is necessary to continue with the control to keep results.

� The seed bank is decreasing because of the continued elimination works carried out for the last years.

� The presence of Baccharis halimifolia is reducing in every plot that have been checked.

� Native species are recovering satisfactorily; continued monitoring required to confirm habitat restoration.

www.euskadi.net/life_estuarios

Baccharis halimifolia is one of the most invasive species in Spain (GEIB, 2006). It’s present in all the estuaries of the Basque coast (Herrera & Campos, 2010). The most affected estuary is the Biosphere Reserve of Urdaibai (Bizkaia), where more than 300 hectares are covered (A. Prieto, 2005).

The main objective of the Life+ project is the elimination of the invasive specie in three Basque estuaries within the Natura 2000 network, to assist the regeneration of the natural plant species.

� Effectiveness criteria: check resprouted stumps� Baccharis halimifolia colonization capability: check seed bank (seedlings)� Habitat recovery: check presence and abundance of native species� Environmental impacts: analysis of soil and aquatic organisms for glyphosate exposure.

Effectiveness of elimination works:� Resprout rate 16,8 %; high variability between plots and transects (Graph 1.)� Generally, the greater the number of stumps, the higher the effectiveness is (human factor?) (Graph 2.)

Colonization capability:� Estimated average seed bank: 1seedling/m2

� Marked reduction with respect to previous campaigns (10,28 seedlings/m2 in 2008)

Habitat recovery:� Most abundant native species in plots: Atriplex prostrata, Juncus maritimus and Phragmites australis;�(25% average abundance; 100% maximum abundance)� Baccharis halimifolia present in 70% of plots; (average abundance < 10%; maximum abundance about 50%)

For seedlings: Clearing

� Campos, J.A. & M. Herrera (2009). Diagnosis de la Flora alóctona invasora de la CAPV. Dirección de Biodiversidad y Participación Ambiental. Gobierno Vasco. Bilbao. 296 pp. � GEIB (2006) TOP 20: Las 20 especies exóticas invasoras más dañinas presentes en España. GEIB, Serie Técnica N.2, 116 pp. � Herrera, M. & Campos, J.A. (2010). Flora alóctona de Bizkaia. Diputación Foral de Bizkaia. Bilbao. 196 pp.

Life08NAT/E/00552010-2014

Total Budget:1.860.000 €

BACCHARIS HALIMIFOLIA ELIMINACION WORKS IN 2011 IN URDAIBAI

INTRODUCTION

MONITORING PLAN AND RESEARCH

RESULTS

CONCLUSIONS

REFERENCES

Technical information140 ha. first treatment (2.600€/ha)

150 ha. revised (1.700€/ha)Number of workers: 10 - 35

Total cost: 621.780 €

Plots Zone A (low flooding) Zone B (high flooding)

A1 A2 A3 B1 B2 B3

Resprout (%) 86,4 90,9 88,2 0 0 20,0

0,0

20,0

40,0

60,0

80,0

100,0

120,0

1 2 4 5 6 7 8 9 10 11 12 14 15 17 19 20 22 23 24 25 26 27 28 29 30 31 32 33

Plots

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0 - 10 % 11 - 40 % 41 - 75 % 76 - 100 %

Resprout (%)

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Transects

Graph 2. Number of stumps and resprout average per plot Graph 1. Resprout average per sampling point

No success

No relevant results regarding diluents, but evidence of the influence of environmental conditions

Zone A

Zone B

Sampling 2 months after works:

� 28 permanent plots (3x3 m)� 30 transects (10x50 m)� 4 soil sampling points and 3

samples per point (12 samples)

� Manual pulling out is the most effective methodology, if the root system is totally removed.

� Specific environmental conditions (high flooding and salinity) seem to increase the effectiveness.

� More improvement test and research have to be launched for further results.

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For adult specimens: Diluent water vs. fuel oil.� 2 sampling zones (different flooding and salinity features)� 3 experimental plots (50% water 50% glyphosate; 75%

water 25% glyphosate; 50% fuel oil 50% glyphosate)

Methodological improvement tests

Manual pulling out

1 clearing each week for 4 weeks

2011 2012 2011 20122010

Total success2 reviews