On threats analysis approach applied to a Mediterranean remnant wetland: Is the assessment of human-induced threats related to different level of expertise of respondents?

Naming, listing and measuring human-induced threats in protected areas are crucial in conservation. Here, we defined a check-list of direct threats in a Mediterranean remnant wetland (central Italy), managed as nature reserve, grouping them according to a taxonomically-oriented nomenclature. We assessed three regime parameters (scope, severity, and magnitude) applying an experience-based method, then comparing the assessments obtained from two different level of expertise: a panel of independent people, upper level university students in an applied ecology class; and a panel of experts as nature reserve biologists and managers. Despite observing a significant correlation among values assigned from students and experts for each regime parameter, students underestimated the scope of feral dogs, the severity of fires and the magnitude of feral dogs and water stress. Considering only the magnitude values (sum of scope and severity), students assigned the higher values to alien species, antropophilous species, aircraft, and pollution, while the experts assigned the higher values to antropophilous species, aircraft, alien species, and water stress. In an order of priority, there was an agreement between students and experts with a coincidence for three threats out of four. We suppose that a panel of students with a short academic training could be useful to a get a first order of priority in regard to a set of local selected threats, with much similarity to the assessment obtained from a panel of experts. When threat metrics are difficult to compare, experience-based approach obtained from technicians trained ad hoc (students) could be useful to define priorities for management strategies in nature reserves, but data obtained should be examined critically. Indeed, students may assign higher scores to regime parameters of threats more readily identified and perceivable, underestimating the threats with an inconstant regime, localized in time and space, mobile, or cryptic. If experience-based methods are used to define scale of priorities, these issues need to be considered.