Despite its central role in many ecological applications, wildlife habitat is poorly defined in operational terms. Consequently it is difficult to assess the extent to which human activities, including forestry, may affect habitat quality to animals. Forestry has the potential to impact vast areas of land across ecological time frames, strongly affecting the long-term capacity of an area to provide resources for wildlife. To enhance our knowledge on the functional relationship between wildlife and forestry practices, and therefore to inform forestry planning as to which are the silvicultural practices best suited to enhance habitat quality for wildlife, we will focus on the highly endangered Apennine brown bear. The Apennine bear is a strictly forest-dependent species, and represents an excellent flagship to tackle with the issue of improving habitat quality for wildlife while allowing for compatible forestry practices, an issue rarely addressed in Italy. Especially within protected areas, the traditional approach of leaving forests unmanaged does not necessarily translate in enhanced habitat quality. Bears, in addition to large patches of old-growth forests where they locate dens and retreat sites, also tend to favor clearing, edges, and young forest stands where food resources are plentiful. By extending our previous research on bear ecology and conservation, and taking advantage of a rich dataset of bear movement data we collected through satellite telemetry in the Abruzzo National Park, our aim is twofold: (i) to enhance our knowledge regarding selection patterns of bears towards forest structural variables (i.e., DBF and tree density), and (ii) based on modeled bear-forest relationship and landscape forest dynamics, to project habitat suitability for bears in the next 100 years according to alternative forestry regimes. This will prove critical to inform forest planning to enhance habitat productivity for bears while allowing for timber use by local residents.
Forestry and Wildlife Ecology and Management are two scientific disciplines originally based and developed on different cultural and applied backgrounds. Although both disciplines are rooted in the paradigm of sustainable yield, timber harvest practices have been traditionally oriented at commercial production of wood and, until very recently, have not contemplated the idea that forested ecosystems should be viewed as habitats for wildlife. On the other hand, models of critical wildlife habitat have traditionally contemplated broad land use categories and largely ignored the structural nature of forests, hampering progress towards understanding the effect that timber harvest may have in the short- and long-term on the availability and quality of habitat for wildlife species associated to forested ecosystems.
Our project stays at the core of the dualism between forestry and wildlife conservation, attempting to converge different applications (i.e., wood for resident populations and conservation of wildlife habitat) through shared practices. To this aim, the Apennine bear is an excellent flagship species for promoting innovative forest planning and management paradigms at the local, regional and statewide scale. Indeed, a central mechanism to the conservation of endangered and threatened species is the designation of critical habitat (e.g., EU Habitats Directive), which requires an understanding of habitat quality [1]. By developing bear-habitat models that contemplate forest structure and composition, and by projecting forest structure and composition in the future according to alternative forestry regimes, it will be possible to identify which silvicultural techniques are best suited to provide woods for local residents while maintaining of enhancing habitat quality for bears.
We believe the above information will be critical in advancing the forest management practices also inside protected areas where forests are traditionally treated as unmanaged forest. In this conditions, forest structure and productivity may decline with time. Stages that favor early successional species, some of which produce important foods to bears such as grasses, forbs insects and soft mast, tend to close with the advancement of the forest stand age [2]. Suppression of forest harvest across the Apennines has recently led to increased woody encroachment of natural openings [3] and extensive succession of early seral or open structured stands. These conditions can lead to declines in brown bear populations [4]. With regard to the Apennine bear, woody encroachment and medium-aged forest stands (i.e., 20-50 years for beech forests) tend to reduce the availability of soft mast and vegetation palatable to bears. At the same time, Apennine bears also rely on beech nuts and acorns during hyperphagia and, in years of low hard mast production, switch to soft mast as a complementary food [5]. Forest management, through development of early seral stage communities, may therefore offer an opportunity for management of bear habitat [6]. However, even though forest planning largely affects the overall habitat quality and configuration of bear habitats in forested landscapes, no such studies have ever been conducted Europe, including Italy.
The recent availability of highly accurate data on animal movement, such as those acquired through the GPS technology, coupled with the impressive improvement of statistical and modeling techniques in a GIS environment, now allow researchers to investigate with greater power and resolution the relationship wildlife species have with their environment. More than in the recent past, this allows to contemplate the effect of silvicultural practices on the quality of habitats for wildlife species, and accordingly inform forest management. We intend to perform such analyses on the Apennine brown bear, also to foster a culturally innovative approach to forestry, especially inside protected areas, and believe pur approach is extendable to all wildlife species living in forested ecosystems.
The data we have at hand on the Apennine bear population, the modelling expertise of our GIS lab, and the network of collaborators we have among forestry experts and managers, all contribute to make our project realistic and markedly innovative for the benefit of both Forestry and Wildlife Science.
Our project also matches objectives and actions planned in the National Plan for the Conservation of the Apennine Brown Bear, issued and promoted by the Ministry of the Environment [7: Action B6].
References
[1] Kosterman et al 2018. Ecol Appl 28:1032¿1043
[2] Reynolds-Hogland et al 2007. J Appl Ecol 44:1166¿1175
[3] Falcucci et al 2008. J Mamm 89:1502¿1511
[4] McLellan & Hovey 2001. J Wildl Manage 65:92¿99
[5] Ciucci et al 2014. J Mamm 95:572¿586
[6] Nielsen et al 2004. For Ecol Manag 199:51-65
[7] AAVV 2011. Piano d¿Azione Nazionale per la Tutela dell¿Orso Bruno Marsicano. Quad Cons Nat 37, Min Ambiente