The dwarf bulrush: conservation status in France and ......Conservatoire Botanique National Alpin...

The dwarf bulrush: conservation status in France and restoration

perspectives

Renaud JAUNATRE a,b, Noémie FORT c, André EVETTE a,b, Morgane BUISSON d

a Irstea, UR EMGR Ecosystèmes Montagnards

b Université Grenoble Alpes c Conservatoire Botanique National Alpin

d Syndicat Mixte des Bassins Hydrauliques de l’Isère – Service grands projets

Re

4th European Typha minima group Workshop Sigoyer, June the 24th

Synopsis

1 CBNA and Irstea presentation

2 Dwarf bulrush french current situation

3 A species impacted by river amenities

4 Dwarf bulrush integration and restoration perspectives in the Isère amont » project

1. CBNA presentation Conservatoire Botanique National Alpin http://www.cbn-alpin.fr • public organism dedicated to the knowledge and preservation of french alps and its piedmonts flora and vegetation http://www.cbn-alpin-biblio.fr/ http://www.cbn-alpin-icono.fr/

Conservatoire Botanique National Alpin • > 5 millions of observations to characterize 5700 species on a 42600km2 territory - Historical datas from herbaria

vouchers - Field datas since 1985 :

floristic and phytosociological surveys

-> atlas, flora… -> identification of most rare and threatened species : protection lists, red lists Common and rare species, exotic species, bryophytes, habitats…

1. CBNA presentation

Conservatoire Botanique National Alpin • conservation activities - on priority species ->

conservation strategy - With a network of 28

pratictionners and researchers • Monitoring at different scales • Ex situ conservation - Seed bank and conservatory

garden - Germination and cultivation

studies - Common garden experiment

linked with research programms

1. CBNA presentation

Irstea is a research organism studying the issues of a responsible agriculture and a sustainable territory planning www.irstea.fr Scientific strategy of Irstea concerns : - a sustainable management of territories, including agricultural and suburban, resources (especially water), their products (food and energy), but also the human, economic and financial fluxes; - Prediction and prevention of natural (floods, flooding, avalanches) and environmental (chemical, biological ...) hazards - The preservation of biodiversity and its participation in the production of resources (forest biomass).

1. Irstea presentation

Irstea is distributed in 9 sites in France Irstea Grenoble center develops research and expertise for knowledge and ecosystem, territories and natural hazards management in the mountains.

1. IRSTEA presentation

2. Dwarf bulrush french current situation

• occidental limit of its distribution area Rhône-Alpes and PACA region on Arve, Giffre, Arc, Isère, Durance Drac, Buech, Eygues, Ubaye, Var, Verdon, Rhône rivers …

2. Dwarf bulrush french situation


Be careful with interpretation… Increase of prospecting pressure with time


• Conservation status : (Prunier et al. 2010), - 85% for the Alps in one century, - 50% for France • national protection, red list PACA (NT) et RA (EN) • First cause of regression : regular amenities in the beds of rivers, profoundly altering river dynamics and reducing favorable biotopes

Conservation work realized - Complete survey : regular reactualization, targeted prospection - Monitoring of defined localities - Ex situ conservation : seed bank (32 accession from 25 localities) - Study of genetic diversity and structure (Till-Bottraud et al. 2010) showing

importance of sexual reproduction by seeds - Great involvment of practionners - Sensibilization of private companies


Issues Establish a monitoring populations and habitats -> protocol? Preserve the presence of favorable habitat Maintain subpopulations interconnected network -> Integration of the species and its habitat in the management of rivers : restoration of river functionnality -> Artificial temporary maintenance sources populations


River developpement project Isère Amont, SYMBHI, Isère, 2009 -> 3. Durance EDF : maintenance of Durance river bed , St Lazare reservoir in Sisteron, 2003, 2009 - Rhizomes collect and culture - Avoidance and protection of localities - Remodeling spaces for reimplantation of typha rhizome collected - Tested areas for news methods of favorable ecological management

Contribution to genetic study launched in the project Isère Amont


Renaturing process on river Drac, Hautes-Alpes 2012: restauration of hydromorphological functionnality - Removal and resettlement of the population on favorable habitat after the

operation - But disappearance of the station before works

Repair of Vallabrègues dike, Rhône, Gard 2014 - Removal and reinstallation of the population on favorable habitat after work


Conservatoire Botanique

National Alpin

Amenities of the lower Var valley (06) Projects in the bed of the Var : threshold reduction, reinforcement of dikes, maintenance of microcentrals, motorized activities -> Small local Action Plan - Current knowledge - shared diagnosis of activities and projects and their interactions with tdwaef bulrush - Action sheets : Increase account of the species in the different projects Preserve the natural environment and the dynamics of the river Maintain a large enough and functional populations



National Alpin

Objectives of the « Isère amont » project • Protection against floods • Developpement of natural recreation spaces • Enhancement of natural environnment

4 Dwarf bulrush integration and restoration perspectives in the « Isère amont »

Lattitude, 2009

Lattitude, 2009


National Alpin

Objectives of the « Isère amont » project • Protection against floods • Developpement of natural recreation spaces • Enhancement of natural environnment

Lattitude, 2009

Lattitude, 2009



National Alpin

L. Lhoste

L. Lhoste

te

L. Lhoste

Typha minima : 39% localities impacted by works

As part of the development of natural areas

and compensation measures : monitoring and restoration trials of populations

4 Dwarf bulrush integration and restoration perspectives in the « Isère amont » Objectives of the « Isère amont » project • Protection against floods • Developpement of natural recreation spaces • Enhancement of natural environnment


National Alpin

Study of Typha minima ecological niche Objective : better understanding of the T. minima ecological niche on the isère riverside Three dimensions :

o hydrogeomorphological parameters o Height relative to the water o Characterization of the biotic environment

Hypothesis : localities are rather inside meander hesis : localities are rather inside meand

http://www2.ggl.ulaval.ca/personnel/bourque/s3/eaux.ruissellement.html

Stage Marion Martinelli 2015 4 Dwarf bulrush integration and restoration perspectives in the « Isère amont »


National Alpin

Methods : - Calculations of angles at any point in the Isere river - Calculations of angles for each locality

Stage Marion Martinelli 2015 Study of Typha minima ecological niche Objective : better understanding of the T. minima ecological niche on the isère riverside Three dimensions :




National Alpin

Stage Marion Martinelli 2015

- significant but very small effect - Others dimensions are to explore

- Effect of channeling?

Chi²=15,7

df=7

p=0,028)




Methods : - Calculations of angles at any point in the Isere river - Calculations of angles for each locality - comparison


National Alpin


Hmin Hmax

Methods : -measure of max and min heigh measure of max and min heigh

Corrected to Isère mean level





National Alpin


Hauteur par rapport au niveau moyen de l’Isère

% d

e st

atio

n pr

ésen

tant

des

Typ

ha p

our u

ne

haut

eur

Results : Heightss- Localities between entre 7cm et 257cm

30% localities have Typha at 37cm

72% localities have Typha at 77cm

40% localities have Typha at 157cm t aa%

de

stat

ion

prés

ent

hahaValues to be considered for

future transplants

The amplitude of heights allows Typha to maintain for various hydrological conditions





National Alpin


Methods : - Surveys IN and OUT localities





National Alpin


Methods : -Surveys IN and OUT localities -identification of species with high affinity -identification of species with high co-exclusion


o hydrogéomorphological parameters o Height relative to the water o Characterization of the biotic environment



National Alpin


Typha aside, the composition and outside the stations is not different

-No High affinity species -No Species with high co-exclusion

So much that the bench is there Typha seems able to maintain

- is salix really a competitor? Or does it accelerates aggradation?

Methods : -Surveys IN and OUT localities -identification of species with high affinity -identification of species with high co-exclusion


o hydrogéomorphological parameters o Height relative to the water o Characterization of the biotic environment



National Alpin

Stage Vincent Bourret 2015 4 Dwarf bulrush integration and restoration perspectives in the « Isère amont »

Typha minima trial transplantation study

Objective : Optimize transplantation methods

Methods : - setting nursery culture - 3 Types of transplants: container, buckets and bare roots


National Alpin

Stage Vincent Bourret 2015

Racines nues

Godets

Conteneurs

4 Dwarf bulrush integration and restoration perspectives in the « Isère amont » Typha minima trial transplantation study


Methods : - setting nursery culture - 3 Types of transplants: container, buckets and bare roots - transplantations in autumn 2013 and 2014


National Alpin


Methods : -setting nursery culture -3 Types of transplants: container, buckets and bare roots -transplantations in autumn 2013 and 2014 results: Typha frequency




National Alpin


Methods : -setting nursery culture -3 Types of transplants: container, buckets and bare roots -transplantations in autumn 2013 and 2014 results: Nb of inflorescences

Objective : Optimize transplantation methods Typha minima trial transplantation study



National Alpin

Stage Vincent Bourret 2015 4 Dwarf bulrush integration and restoration perspectives in the « Isère amont »



Methods : -setting nursery culture -3 Types of transplants: container, buckets and bare roots -transplantations in autumn 2013 and 2014 results: Rhizome growth (in cm)


National Alpin


Methods : -setting nursery culture -3 Types of transplants: container, buckets and bare roots -transplantations in autumn 2013 and 2014 results: Rhizome growth (in cm)




National Alpin




The three techniques enable the development of new populations

The rapid development of populations

depends on the amount of biomass introduced

The differences between the techniques seem to fade with time



National Alpin

Prospect Extend the "niches" work on less anthropized rivers Transplant techniques allow to maintain source populations during the works but what about the long-term dynamics? Possible compromise between dynamic rivers and human uses?


Thanks for your attention

The dwarf bulrush: conservation status in France and ......Conservatoire Botanique National Alpin...

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