Spatial patterns of tree-related microhabitats: key factors and ecological significance for the conservation of the associated biodiversity

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Larrieu, Laurent and Bouget, Christophe and Courbaud, Benoît and Gouix, Nicolas and Goulard, Michel and Kraus, Daniel and Lachat, Thibault and Ladet, Sylvie and Paillet, Yoan and Rose, Olivier and Stillhard, Jonas Spatial patterns

of tree-related microhabitats: key factors and ecological significance for the conservation of the associated biodiversity. (2018) In: 5. European Congress of Conservation

Biology, 12 June 2018 - 15 June 2018 (Jyvaskyla, Finland). (Unpublished)

Open 1\r<.;hivc 'l'uuluusc Archive Ouvcrlc (OA'l'AO)

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Spatial patterns of Tree-related Microhabitats:

key factors and ecological significance for the conservation of the associated biodiversity

5th_{European Congress of Conservation Biology, Jyvaskyla, Finland, 12-15}th_{June 2018}

Laurent LARRIEU Christophe BOUGET Benoît COURBAUD Nicolas GOUIX Michel GOULARD Daniel KRAUS Thibault LACHAT Sylvie LADET Yoan PAILLET Olivier ROSE Jonas STILLHARD ~l ii~ q,1•muschE

8.

,;,;= C ~F r ,s,AA!!;;,"'.),'(::,J:;t\' . OYN. rt)R 1-'I a , •.. •-"" ,.,,,.,,.,,., WSl _f,,,1_~_""'''· ol ' " ' " " ' • ,. . . Conservatolres ~ d'espaces naturel5

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A Tree-related Microhabitat (TreM) is a specific above-ground tree morphological singularity (Larrieu, Paillet, Winter et al. 2017)

• distinct, well delineated structure

• borne by standing living or dead trees • essential substrate or life-site for taxa

• encompassing decaying wood (=saproxylic TreM) or not (=epixylic TreM)

Practical issues

Introduction Spatial patterns Old growth forests Managed stands TreM-dwelling taxa

Drawings L. Apfelbacher

Cavities Injuries Crown deadwood Excrescences Fungi Epiphytes Exudates

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Stand scale s s c c c

TReMs are key features for many taxa and participate in a complex functional habitat network in species life cycles

Examples of supplementation (s) and complementation (c) resources

Practical issues

TreM scale

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4 = TreM-bearing trees ø

ø

% T reM -be ari ng tr ee s N/ha N/ha TreM TreM + TreM

%

N/ha TreM

(See also: Michel et al. CJFR 2011; Vuidot et al. BC 2011; Regnery et al. FEM 2013)

Large trees bear most of the TreMs within a forest stand (e.g. Larrieu et al. EJFR 2012) Practical issues

0 (D 0 It) 0 st 0 ('I) 0 N 0 _,.. o~ :d::t::__J__L_J__L_JI:::::3:~~ ST LT VL LST < 17.5 17.5 -27.5 27.5-47.5 47.5 - 67.S 67.5-87.5 > 87.5 d1ame er category (cm) C0 ci (\I 0 0 ci

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Old growth forests Managed stands Stochastic events • Neighbour-tree falling • Lightning • Wind damages • Rock fall Biotic processes • Woodpecker drillings

• Between-tree light competition • Cambium dysfunctioning

• Etc.

Forestry operations

• Tree-marking

• Harvesting injuries

Does the spatial pattern of the largest trees drive the spatial pattern of the TreMs at the stand level?

Practical issues

Tree dbh ?

-

.,

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Practical issues Introduction Spatial patternsSpatial patterns Old growth forestsOld growth forests Managed stands TreM-dwelling taxa

At a multi-site sample level, the probability of bearing a TreM

increases with dbh but the direction of this relationship is variable at the plot level

• Time since the last harvest > 100 y • 5 sites/126 plots/5519 trees

• 11 TreM groups

• GLM binomial (Y=with a TreM or not)

> Fagus sylvatica _50% Spatialized dbh model *** Non-spatialized dbh model P robab ili ty to be ar a Tr eM (fi tt ed v alues ) ø ø global plot ø ø a(plot) + b(plot) * dbh a(plot) + b * dbh 1 plot.. 50 100 50 ) )

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Time since the last harvest influences the spatial pattern of the TreM-bearing trees

Practical issues Introduction Spatial patternsSpatial patterns Old growth forestsOld growth forests Managed stands TreM-dwelling taxa

• 25 sites/165 plots/11425 trees • 11 TreM groups

• GLM binomial (Y=with a TreM or not) • 4 variables describing tree-neighborhood

-d to the closer TreM-bearing tree -d to the closer tree without TreM

-nb TreM-bearing trees in a 40m-buffer -nb trees without TreM in a 40m-buffer

Time since the last harvest

D e vian ce exp lain e d b y the mod e l

Significant deviation values compared to null model

>

Fagus sylvatica 50%

>100y _50-100y _<50y

I[). C'\I 0 0 _I I I I I I 0 I I C\l I I I I I I I I I I I I LO T""" 0 0

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Studying spatial distribution pattern of TreM-bearing trees is more challenging than expected…

 Some preliminary results

• No clear and universal spatial pattern by analyzing a set of 11 TreM groups • In addition to a dbh effect, there is a strong site_plot_managing effect

 Some methodological challenges in spatial pattern study

• Scarcity of most of the TreM types  need of large-area plots with georeferenced trees

• But changing the spatial extent and the grain size may affects the results (in agreement with the « Modifiable Areal Unit Problem”, Openshaw 1983)

• Need of additional variables describing the local context: slope, presence of cliffs, woodpecker assemblages, etc.

• TreMs are “ephemeral resource patches” (sensu Finn 2001)  dynamic spatial distribution patterns Practical issues Introduction Spatial patternsSpatial patterns Old growth forestsOld growth forests Managed stands TreM-dwelling taxa

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Is the dissimilarity of assemblages hosted by tree-cavities related to the between-cavity geometric distance?

Practical issues Introduction Spatial patterns Old growth forests Managed stands TreM-dwelling taxa

« distance decay of similarity » (Nekola & White, 1999)

1 km emergence trap Gresigne (France) Quercus petraea Base rot-holes 189 traps 1year Trunk Cavity Collecting flask Pipe Canvas Mould Fagus sylvatica Base rot-holes 50 traps 1year Trunk Cavity Collecting flask Pipe Canvas Mould 100 m Uholka (Ukraine) • • ' • II • • • ., • ••

..

• r ~ /

~

•

0 0 I "' ., e, I .,

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The closer, the more similar? The distance decay of similarity pattern for cavity-dwelling biodiversity is not consistent

ns

***

Distance between trapped cavities

Gresigne (France) Uholka (Ukraine)

Practical issues Introduction Spatial patterns Old growth forests Managed stands TreM-dwelling taxa

0 6000 m 0 400 m q ₀ _C!Dl) ₀ cP @o 0 _/pO OD ₀ ₀ 0 ₀ 0 'o 0 00 ₀₀ 0 0 0 0 0 0 00 0 0 0 0 0 00 0 0 0 0 0 ~ _{00 Cl>} ₀₀ ₀ OODO 0 co 0 0 0 00 0 0 000:000 0 0 0 0 0 00 00 0 COll) 0 (Q) ₀ ₀₀₀ 000 (Q) ~ ₀ 0 0 0 0 0 00 C03I!) 00 00 0 0 ~ 0 C\J 0 0 0 0 00 0(11) 0 0 0 4000 100 200 300

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Does an increasing density of sporocarps at tree or plot scales foster the mean species richness of fungus-dwelling beetles in sporocarps?

The Vosges mountains (France)

COM FRA VEN1, 2 et 3 Fagus sylvatica • 196 traps • 1 year Fomes fomentarius Practical issues Introduction Spatial patterns Old growth forests Managed stands TreM-dwelling taxa

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Fine-scale habitat aggregation has a positive effect on the local species richness of fungus-dwelling beetles…

Practical issues Introduction Spatial patterns Old growth forests Managed stands TreM-dwelling taxa

Tree-scale

***

0.3 ha scale

ns

See also Jonsell et al. (1999); Rukke et Midtgaard (1998) …but neither mass effect nor dilution effect of mid-scale habitat aggregation

• .. '° -• • _• • _• • 0 _•• _o _. • Cl) .. .. ... .. .. _• .. .. (l) ... ... .. • _{• •} .. .. _• u ..._. . _• _• _• (l) • • • • .. • CL Ul Cl) .... .... .. .. • .. • .. .. Q) • • .. ;:::; • • • • _• .. Q) Q) • .. .. • .. C 0 ₀ - • • • • • • • • .... ... C _• _• _• .. _• .. _• _• C _• ... _• .. ... .. • .. .. • • .. • ... ... .... .. _• .. _• .. _• .. _{• • •} .. _• .... .. ... • .. _{• •} .. .. _• lO ... ... .. _IO_- _• .. _• .. ... • ... ... ... _• .. _{• •} .. .. _• • .. _• _• ... _• .& ... .. .& ... • .. _• _• .. 0 ₀ _. . 0 10 20 30 40 ₀ ₂ ₆ ₈ ₀ ₂

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Practical issues

Introduction Spatial patterns Old growth forests Managed stands TreM-dwelling taxa In a nutshell…

Thank you for your attention

 Spatial scale of studies strongly influences :

 The relationship between tree-dbh and the probability to bear a TreM  The relationship between spatial patterns of TreMs and associated

biodiversity

 Other features than tree-dbh should be considered to explain

spatial patterns of Trem-bearing trees

 Both alpha and beta diversity of TreM-dwelling beetles may be influenced