Uncertainty in expert knowledge of forest succession: A case study from boreal Ontario

Abstract

Expert knowledge of forest succession is used widely in forest management planning, but its level of uncertainty is unknown. Using boreal Ontario as an example, we examined the level of uncertainty in expert knowledge of forest succession and explored possible sources of this uncertainty. Overall, the level of uncertainty associated with expert knowledge was high for all aspects of forest succession, except for post-fire species establishment. Higher levels of uncertainty were associated with knowledge of forest succession for mixed forest types and moderate site conditions, as opposed to coniferous or non-coniferous forest types and extreme dry/wet or poor/rich sites. We hypothesize that uncertainty in expert knowledge is highest when vegetation dynamics are highly stochastic as with complex species assemblages, environmental controls on succession are weak, and effects of disturbances are less drastic. Awareness about the degree of uncertainty in expert knowledge of forest succession could be incorporated into forest management decision processes. It could also help researchers to identify critical knowledge gaps to guide further studies.Key words: uncertainty assessment, post-fire establishment, natural succession, knowledge elicitation RÉSUMÉ La connaissance experte de la succession des forêts est largement utilisée dans la planification de la gestion forestière, mais son niveau d'incertitude est inconnu. En utilisant la forêt boréale de l'Ontario comme exemple, nous avons examiné le niveau d'incertitude sur le plan de la connaissance experte de la succession des forêts et avons tenté de découvrir les sources possibles de cette incertitude. Dans l' ensemble, le niveau d'incertitude lié à la connaissance experte était élevé pour tous les aspects de la succession des forêts, sauf pour ce qui est de l' établissement des espèces à la suite d'un feu de forêt. Des niveaux d'incertitude plus élevés ont été liés à la connaissance de la succession des forêts pour les divers types de forêts mixtes et les régions caractérisées par des conditions climatiques modérées, contrairement aux types de forêts de conifères ou autres que de conifères, de même qu'aux régions caractérisées par des conditions d'aridité ou d'humidité extrême ou peu ou très fertiles. Nous sommes partis de l'hypothèse que l'incertitude sur le plan de la connaissance experte est la plus élevée lorsque la dynamique de la végétation est extrêmement stochastique, comme c' est le cas avec les assemblages d' espèces complexes, que les mesures de contrôle environnemental sur la succession sont faibles et que les effets des perturbations sont moins drastiques. La sensibilisation au niveau d'incertitude sur le plan de la connaissance experte de la succession des forêts pourrait être intégrée aux processus de décision en matière de gestion forestière. Cela pourrait également aider les chercheurs à déterminer les lacunes cruciales en matière de connaissance en vue d' orienter les études à venir.Mots clés : évaluation de l'incertitude, établissement à la s...

Parsimoniously modelling perennial vegetation suitability and identifying priority areas to support China's re-vegetation program in the Loess Plateau: Matching model complexity to data availability

“…Note, 'trees' is target level 1, 'shrubs' is target level 2 (see Table 3), and grasses are assumed to not change the hydrological simulations from the current conditions (as grass is the current predominant land use) and thus are not reported here. Drescher et al, 2008). The term 'ecological interactions' incorporates many issues such as competition for resources (both interand intra-species), and grazing when considering vegetation in ecosystems .…”

Toward rigorous use of expert knowledge in ecological research

“…Where structured elicitation is used, epistemic and linguistic uncertainty can be evaluated and minimized. For example, epistemic uncertainty may be assessed through selfevaluation by experts, where they provide the outer limits of some estimate of a probability of occurrence, credibility intervals, or a qualitative estimate of their confidence in an estimate (Sutherland 2006, Van der Lee et al 2006, Drescher et al 2008). Linguistic uncertainty is addressed most easily v www.esajournals.org through the design of a transparent elicitation process and the application of appropriate treatments when examples arise .…”

“…However, these experts will not perfectly agree with each other and may even contradict one another, which can be referred to as source conflict (Smithson 1999). Sometimes this amongexpert uncertainty is acknowledged (Iglesias and Kothmann 1998, Drescher et al 2008, Hurley et al 2009), though most expert knowledge studies do not partition the different sources of uncertainty and only report aggregated expert knowledge. Nevertheless, among-expert disagreement can provide valuable information about the characteristics of the studied system (Uusitalo et al 2005), research needs (Morgan et al 2001) and about the nature of expert knowledge itself (Iglesias andKothmann 1998, Drescher et al 2008).…”

Characterizing demographic parameters across environmental gradients: a case study with Ontario moose (Alces alces)

“…Use of a temporally explicit landscape would permit exploration of how quickly timber harvest produces new moose foraging habitat. Succession rates and stand composition post-harvest have been extensively studied in Ontario, and the boreal forest in general (i.e., Carleton 2000, Chapin et al 2004, Drescher et al 2008; however, how patterns of succession and temporal dynamics of vegetation composition influence utilization of clearcuts by moose remains unclear. Generally, we expect moose to begin utilizing clearcuts as early as one growing season following timber harvest as the understory regenerates, but few studies have examined over what duration such utilization improves foraging efficiency and how this improvement influences carrying capacity (but see Stephenson et al 2006).…”