How to balance forestry and biodiversity conservation – A view across Europe
Hèches – ‘Groupement Forestier des montagnes particulières de’: a case from the mountains of southwestern France
L. Larrieu
1, G. Verdier
21 INRAE, UMR Dynafor, Castanet-Tolosan, France; CRPF Occitanie, Tarbes, France
2 GF president, Hèches, France
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< Fig. C 9.1. Overview of the GF property; beech-fir stands dominate; however, the complex topography and geology favours a wide range of forest habitats. Because of the a very old tradition of livestock farming, grass- lands have replaced the subalpine forest (Photo: Laurent Larrieu).
Context, legal frame, and ownership structure
The private forest area called ‘Groupement Fores- tier (GF) des montagnes particulières de Hèches’
is located on the northern slope of the central Pyrenees mountains in the region of Occitanie
(fig. C 9.1). The forests here have always been mul- tifunctional, and have mixed wood production, pastoralism, hunting, and harvesting of mushrooms and forest berries.
In accordance with the presence of a wide array of geological substrates, stands thrive in areas where the soil is thick and nutrient-rich, while in
0 0,5 1 2 3km
France
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Table C 9.1. General information on the forests of the GF des montagnes particulières de Hèches.
Forest community Mostly mixed beech-fir montane forest (Fagion sylvaticae and Luzulo-Fagion). Locally Tilio-Acerion ravine forests and Cephalante- ro-Fagion dry beech forest
Total forest area 930 ha (+272 ha of subalpine meadows) Main management type Selective cutting system
Total mean volume Very wide range according to a wide array of soil conditions; from a few m3/ha (rocky soils) to more than 600 m3/ha (thick fertile soils) Annual growth Very variable. More than 10 m3/ha for the most productive stands Deadwood Wide range depending on local conditions and management intensity:
from 9 to 60 m3/ha (diameter >10 cm)
Altitude 620–1900 m a.s.l. (forest: 620–1500 m)
Ownership Private forest; ‘Groupement Forestier’ status
Geology 23 different substrates. Four main categories: (i) hard nutrient-rich Mesozoic limestones and dolomites; (ii) soft nutrient-rich Mesozoic clayey limestones and marls; (iii) acidic nutrient-poor Palaeozoic shales, Mesozoic puddingstones (conglomerate), ophite, etc.; and (iv) very acidic and strongly nutrient-poor Palaeozoic quartzite and shales
Protected area 0 ha
Nature protection area (Natura 2000) 0 ha Protected area for the water spring of the community
20 ha with specific constraints on management Area without harvesting Roughly 200 ha (20 %)
Statement
“In the context of rapid biodiversity loss and climate change, we must adopt a fully integrated management approach to try passing on to our children a property which will last centuries while providing all the ecosystem services we have enjoyed to date.”
other areas (e.g. on rocky soils and in open sunny areas) the stands are made up of small trees. How- ever, the Atlantic macroclimate means that the average precipitation is high and the temperatures are relatively warm (fig. C 9.2), meaning that for- ests can thrive.
The forest owner group is made up of roughly 100 local people. The management decision-mak- ing body is a board with 14 members led by a pres- ident. The forest operations and management are
carried out by the owners themselves. When needed, owners can be helped in technical decision issues by an adviser from the Centre Regional de la Propriété Forestière d’Occitanie (CRPFOcc, Occita- nie Regional Forest Ownership Centre). Except fire- wood, the wood is sold to independent forest oper- ators. Every summer, sheep, cows, and horses are grazed on the subalpine meadows. The animals belong to two of the owners of the GF, but also to livestock farmers who lease the right to graze their
Timber/Biomass
Non-timber products
Erosion
Protection
Biodiversity Recreation
Landscape Climate Groundwater
C 9 Hèches, France
animals on the land. Hunting rights and rights to mushroom harvesting are reserved for the GF own- ers and village inhabitants.
Two of GF’s owners are employed part-time as rangers, with one focussing on forest issues and one focussing on livestock issues.
Portrait
“As the president representing the owner set of the GF, my mission is to apply sustainable and mul- tifunctional management that benefits the owners, but also the other villagers. The challenge is to rec- oncile production of high-quality timber, hosting of livestock, the presence of a large game population allowing traditional hunting activities, and finally harvesting of edible mushrooms and berries. In addition, this property is also an area for recrea- tional activities for people from outside the vil- lage.”
Forest history and cultural heritage
The subalpine meadows have been grazed by live- stock for >5000 years. Old maps (Cassini’s maps, 1770; Vallauri et al. 2012) show a forest cover simi- lar to the current one. Most of the stands were har- vested periodically between the seventeenth and twentieth centuries, mainly for charcoal produc- tion. In the nineteenthcentury, the forest owners were also the owners of steel mills.
A group of local farmers bought the property in 1860, with the main aim to use the subalpine meadows for livestock grazing in summer. Livestock also used some stands for grazing, particularly the stands alongside paths, and stands located on south-facing slopes which are sunny and become free from snow early in spring. Wood products were mostly for domestic use (firewood from broadleaves, timber from silver fir) or charcoal pro- duction for the local steel industry (that were in production until 1943). For charcoal production, stands were managed according to the coppice selection method. This forest history explains the current dominance of beech (Fagus sylvatica) at the expense of silver fir (Abies alba) since grazing, fire and intensive logging favours tree species which can sprout.
In the period from the end of World War II to 1978, there was very little harvesting. In 1979, the owners shifted to timber production. However, summer grazing by livestock remained a necessity.
A huge effort to build a road network (about 45 km) combining both truck and dirt roads pro- vided access to about 80 % of the area. As beech timber has a high value, the stands were regularly logged until 2000, and annual harvesting was on average about 3000 m3. A drop in wood price slowed down the rate of logging after 2000 and to 2010. Since 2010, about 6000 m3 of timber have been harvested annually.
Stands are mainly composed by naturally regen- erated native species (fig. C 9.3). There are only a few plantations of non-native conifers (about 10 ha),
Fig. C 9.2. Weather data (Hèches, 940 m a.s.l., Aurelhy model, 1981–2010); panel a: ombrothermic diagram using the scale ratio P = 3T since macroclimate is Atlantic; panel b: Climate graph, numbers indicate months.
0203 04
05 07 08 06
09
10 11
12 01 Months
01 02 03 04 05 06 07 08 09 10 11 12
a b
Temperature
Precipitation
Growing season
180 mm 150 mm 120 mm 90 mm 60 mm 30 mm 0 mm
60°C 50°C 40°C 30°C 20°C 10°C 0°C
25°C 20°C 15°C 10°C 5°C
0°C20 mm 40 mm 60 mm 80 mm 100 mm120 mm 140 mm160 mm
Precipitation
How to balance forestry and biodiversity conservation – A view across Europe
including Douglas fir (Pseudotsuga menziesii), black pine (Pinus nigra), European larch (Larix decidua).
Some native broadleaved species have also been planted, including sycamore (Acer pseudoplatanus), wild cherry (Prunus avium), and beech (about 20 ha).
The conifers were planted in 1992 and the broadleaves were planted in 1997, on ancient graz- ing or burned areas.
The water spring, used for decades by the whole village, is located on the property. A new protection buffer has been set up in 2000, strictly protecting about 0.2 ha and constraining the management of forest on the 20 ha around the spring.
Aims of the owners
In a global framework of sustainable management, the current economic aims of the owners are to obtain an income from timber, provide annual fuel- wood for the owners (about 120 m3), and optimise the use of the subalpine meadows by allowing live- stock owners from outside the GF, since there amount of livestock belonging to the local forest owners has declined.
Most important services and products
The wood sale is the most important income for the owners, mostly timber (about 30–45 % of the vol- ume) (fig. C 9.4). The main expense is due to the maintenance of the road network (fig. C 9.5).
Conservation interest – habitats and rare species
Eighteen habitat types have been identified, includ- ing forest and non-forest habitats (Pénin and Lar- gier 2000). Biological inventories revealed the pres- ence of 374 species of beetles (including some rare species such as Teredus cylindricus, Denticollis rubens, Microrhagus emyi or Malthinus bilineatus), 104 species of hoverflies (Diptera, Syrphidae), 17 species of bats, and the spider Harpactocrates ravastellus which is endemic to the Pyrenees (Lar- rieu 2005). Fungi assemblages observed in dry Ses- leria caerulea beech-fir forest are unique in com- parison with other European habitats of Cephalanthero-Fagion (Corriol and Larrieu 2008).
Because of the wide array of substrata and topo-climates, vascular plants are very diverse.
230 534 38
102 21 5
Beech-dominated Mixed Beech-Fir Oak dominated Other broadleaves Conifer plantations Broadleaves plantations
15000 6000
500
Wood products
Livestock (rent of grazing areas)
Hunting
1000
18000 5000
3400
3500
Plantations (cleaning, pruning, etc.) Road network Rangers
Livestock (meadow maintenance, pens) Shepherd huts Fig. C 9.3. Forest area per dominant
stand type (ha).
Fig. C 9.4. Mean annual income for 2014–2019 (€/yr).
Fig. C 9.5. Forest management costs – mean expenses for 2014–2019 (€/yr).
Some of them are protected at the regional or national levels, such as Cerinthe glabra subsp. pyre- naica, Cystopteris montana or Ramonda myconi.
The bryophyte Buxbaumia viridis (fig. C 9.6a) occurs on some large pieces of deadwood in old-growth stands (Larrieu 2005).
Cliffs provide nesting sites for the rare birds Eurasian eagle owl (Bubo bubo), peregrine falcon (Falco peregrinus), Egyptian vulture (Neophron percnopterus), and also for rocky-dwelling bats such as the European free-tailed bat (Tadarida teniotis). The Pyrenean subspecies of capercaillie (Tetrao urogallus subsp. aquitanicus) is found at the upper forest limit (Larrieu 2005).
The forest is fully within a ‘Zone naturelle d’in- térêt écologique, faunistique et floristique’ (ZNIEFF;
Natural zone of ecological interest, fauna and flora).
Nature conservation
The current management plan (2000–2029) includes expert reports about both flora/habitats and caper- caillie. In order to take into account the chemical fragility of certain very nutrient-poor soils (Larrieu et al. 2006), a stand (roughly 20 ha) has been set aside. During harvesting, recommendations of spe- cialised scientists for an insect- and fungi-friendly management (Larrieu et al. 2005, 2008) are taken into account. Even though oak (Quercus petraea, Q. robur) dominated stands have a very low pro- ductivity, no replacement is planned since these stands are used by bats for foraging. A proportion of the very large trees (>70 cm diameter) are retained within harvested stands, and some crowns from harvested trees remain on the ground with- out being cut; however, there is no minimum den- sity or volume of deadwood to be kept in the for- est. Snags are fully conserved; some lying deadwood items are used for firewood when they are very close to roads, but most of them remain within Fig. C 9.6. The Green Shield-moss (Buxbaumia viridis) is mainly observed on large downed coniferous deadwood items (a). The Lesser Stag Beetle (Dorcus parallelipipe- dus): the adult feeds on sap while the larva is saproxylic (b). The Weaver Beetle (Lamia textor) is more commonly observed near streams since its saproxylic larva lives mainly in the deadwood of Salix, Populus and Alnus (c).
The Porcelain fungus (Oudemansiella mucida) is a saproxylic species living in crown deadwood of beech (d) (Photos: Laurent Larrieu [a–d]).
a
c b
How to balance forestry and biodiversity conservation – A view across Europe
stands. In naturally mixed stands currently domi- nated by beech, silver fir is systematically conserved in order to increase its proportion. Post-pioneer tree species are promoted since they support spe- cific biodiversity and they very often have a high commercial value.
In 2004, a harvesting operation was delayed for several months in order to minimise disturbance in
a stand where a breeding pair of goshawks (Accipi- ter gentilis) were found. Climbing is regulated to minimise disturbance to protected cliff-dwelling birds; areas and periods where climbing is allowed are fixed every year in accordance with the bird species and the location of their nests. Figure C 9.7 shows attractive places for nesting sites but also for tourists and adventurers.
Fig. C 9.7. Attractive tourist spots for cavers, hikers and climbers, but also for rare bird species as Eurasian eagle owl (Bubo bubo), peregrine falcon (Falco peregrinus), Egyptian vulture (Neophron percnopterus) (Photo: Laurent Larrieu).
Fig. C 9.8. Important for recreation and production. The entrance to the forests is controlled by gates and only forest owners can access the area by car (Photo: Laurent Larrieu).
C 9 Hèches, France
Recreation
The GF allows free use of cliffs and caves for climb- ers and cavers, and also free use of roads and paths for trekkers. However, forest entrance is controlled by a gate and only owners can drive by car through the area (fig. C 10.8). Hunting and mushroom har- vesting are reserved for the owners and local peo- ple.
Strengths and weaknesses
Management
The GF does not generate enough money to pay for professional forest management, and therefore marking of trees for logging is done by council members; however, none of the council members are professional foresters. In 2017, a marteloscope (a 1 ha silvicultural training site in which all trees are numbered, mapped, and recorded; fig. C 9.9)
belonging to the European network Integrate+
was set up on the property. The council members were trained to carry out the monitoring and meas- urement of the trees. The wood is sold as standing timber by the ‘lump sum’ method (i.e. the timber is sold in advance before harvesting).
Policy
Management daily decisions are taken by the pres- ident or by the board (which meets four times a year). Once a year, a meeting gathers all the mem- bers of the ownership group and the main strategic guidelines are discussed and then approved. Dur- ing this meeting, the president also presents the financial statements.
Science
Since 2000, this property has hosted many ecologi- cal studies focussing on biological conservation and sustainable management. For many studies, the area was one part of a larger study (e.g. Bouget
Fig. C 9.9. The 1 ha-marteloscope was set-up in a beech-fir stand, the dominant stand type on the property (Photo:
Laurent Larrieu).
How to balance forestry and biodiversity conservation – A view across Europe
et al. 2020; Friess et al. 2019; Larrieu et al. 2018;
Courbaud et al. 2017; Müller et al. 2015; Larrieu and Cabanettes 2012). However, this forest was sometimes specifically studied for impact of har- vesting on soil chemistry (Larrieu et al. 2006), on hoverfly communities (Larrieu et al. 2015), on both deadwood and tree-related microhabitats amount (Larrieu et al. 2012), or on beetle communities (Brin et al. 2010).
Adaptive management is not really imple- mented, but the owners have tried to improve the silvicultural methods following the science, e.g. by allowing part of harvested tree crowns to remain in the stand to increase the amount of deadwood amount, or by setting aside stands growing on very nutrient-poor soils.
Communication
Since 2001, the property has been used for training courses about pedology, botany, pastoralism, inte- grated forest management. The target audiences are students, forest advisers, forest managers, and also other private landowners.
Nature conservation is not really integrated by all the GF’s owners, in accordance with a long tradi- tional farming use of the area. However, the presi- dent and other board members are aware of the need to promote more integrated management.
The forest management of the GF has been labelled by the Programme for the Endorsement of Forest Certification (PEFC; certificate 10-21-15).
Conclusion
Owners participating in management decisions or practical issues such as tree-marking need to be better trained. The establishment of the martelo- scope on the property will help to provide informa- tion and to train the owners about biodiversi- ty-friendly silviculture.
Financial incentives to retain very large trees would benefit biodiversity conservation as these trees play a huge role in biodiversity conservation, but landowners often consider them as competi- tors for younger and more productive trees. How- ever, in France, such financial support only exists in N2000 areas.
The amount of deadwood could be increased, e.g. by stopping the harvesting of lying deadwood as a source of firewood for the owners. However,
this action would need a change in the old status of the GF that legally prevents the GF stopping collec- tion of lying deadwood. Pioneer tree species such as silver birch (Betula pendula) and aspen (Populus tremula) should be better considered, in view of their support for biodiversity, although their com- mercial value is low. Finally, when a stand gets a fully regular structure, some mature trees should be retained when the stand is being regenerated to provide ecological continuity between the two commercial cycles.
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