Disentangling, again, the drivers of population decline for two harvested species: a response to Prasad et al. (2014). Issue 3 (15th April 2014)

• Record Type: Journal Article
• Authors: Ticktin, Tamara; Ganesan, Rengaian; Paramesha, Mallegowda; Setty, Siddappa; Hulme, Philip
• Is Part Of: Journal of applied ecology. Volume 51:Issue 3(2014)
• Page Start: 648
• Page End: 654
• Publication Date: 2014-04-15
• Subjects: Agriculture -- Periodicals; Biology, Economic -- Periodicals; Agricultural ecology -- Periodicals; Applied ecology -- Periodicals; 577
• DOI: 10.1111/1365-2664.12249
• Languages: English
• ISSNs: 0021-8901

Abstract

<abstract abstract-type="main" id="jpe12249-abs-0001"> <title>Summary</title> <p> <list id="jpe12249-list-0001" list-type="order"> <list-item> <p>Ticktin <italic>et al</italic>. (2012) (<italic>Journal of Applied Ecology</italic>, <bold> 49</bold>, 774) assessed the dynamics of two Indian tree species (<italic>Phyllanthus emblica</italic> and <italic>P. indofischeri</italic>) and showed that although fruit harvest can decrease long‐term population growth rates (λ), the principal drivers of decline are mistletoe infestation and invasion of an exotic shrub. Prasad <italic>et al</italic>. (2014) (<italic>Journal of Applied Ecology</italic>, <bold> 51</bold>, doi: 10.1111/1365‐2664.12170) questioned Ticktin <italic>et al</italic>.'s approach, showed that <italic>P. emblica</italic> λ values increased when fruit harvest was banned and concluded that fruit harvest has a significant negative effect. We demonstrate that Prasad <italic>et al</italic>.'s analysis is fundamentally flawed and that our conclusions hold firm.</p> </list-item> <list-item> <p>We clarify that our models are built from empirical data collected from field plots. We use life table response experiments to demonstrate that the increase in <italic>P. emblica</italic> λs after the fruit harvest ban is due to higher adult survival and unrelated to fruit harvest. <italic>P. indofischeri</italic> populations show no such increase.</p> </list-item> <list-item> <p>We demonstrate that our results and the literature strongly back up our management recommendations to control mistletoe and the invasive shrub, and protect amla saplings.</p> </list-item> <list-item> <p> <italic>Synthesis and applications</italic>. Prasad <italic>et al</italic>. (2014) confound the effects of time and treatment and therefore reach erroneous conclusions. This highlights the importance of careful analyses to disentangle the effects of multiple drivers of decline for species at risk.</p> </list-item> </list> </p> </abstract>