Changing Perceptions of Change: The Role of Scientists in Tamarix and River Management

Abstract

Initially introduced to western United States to provide ecosystem services such as erosion control, Tamarix by the mid-1900s had became vilified as a profligate waster of water. This large shrub continues, today, to be indicted for various presumed environmental and economic costs, and millions of dollars are expended on its eradication. In this review, we examine the role of scientists in driving changes in perceptions of Tamarix from valuable import to vilified invader and (in some instances) back to a productive member of riparian plant communities. Scientists over the years have sustained a negative perception of Tamarix by, among other things, (1) citing outmoded sources; (2) inferring causation from correlative studies; (3) applying conclusions beyond the scope (domain) of the studies; and (4) emphasizing findings that present the species as an extreme or unnatural agent of change. Recent research is challenging the prevailing dogma regarding Tamarix's role in ecosystem function and habitat degradation and many scientists now recommend management shifts from ''pest plant'' eradication to systemic, process-based restoration. However, prejudice against this and other non-native species persists. To further close the gap between science and management, it is important for scientists to strive to (1) cite sources appropriately; (2) avoid reflexive antiexotic bias; (3) avoid war-based and pestilence-based terminology; (4) heed the levels of certainty and the environmental domain of studies; (5) maintain up-to-date information on educational Web sites; and (6) prior to undertaking restoration or management actions, conduct a thorough and critical review of the literature.

Pour une autre représentation métaphorique des invasions biologiques

“…Précis, ils se réfèrent à des faits, échappent aux considérations externes, telles que leur dynamique démographique ou leurs interactions avec les systèmes écologiques, et sont de ce fait beaucoup moins porteurs de valeurs. L'exploration d'une terminologie dépassionnée s'impose d'autant plus que les systèmes de valeurs ne sont eux-mêmes en rien immuables et que les perceptions concernant les espèces invasives varient dans le temps, comme l'illustrent les exemples du cerisier tardif (Prunus serotina) en forêt de Compiègne (Javelle et al, 2006) ou du tamarix (Tamarix sinensis) aux États-Unis (Stromberg et al, 2009). Ces revirements, qui s'opposent à une perception conventionnelle des espèces invasives, sont salutaires.…”

The distribution of fine root length density for six artificial afforestation tree species in Loess Plateau of Northwest China

“…To address the strategy of plants for water and nutrient use and environmental tolerance, it is important to understand the response of fine roots to the soil environmental factors (Jiao et al, 2010). Some studies about fine roots distribution have been conducted for woody species, suggesting their association with soil moisture, 3 Root distribution in each layer were divided into two size classes based on root diameter: fine roots (≤ 1 mm) and coarse roots (> 1 mm) (Stromberg et al, 2009). Roots were further sorted into live and dead fractions by their color and elasticity.…”

Saltcedar (Tamarix ramosissima) Invasion Alters Decomposer Fauna and Plant Litter Decomposition in a Temperate Xerophytic Deciduous Forest

“…Several impacts have been attributed to saltcedar, such as displacement of native species [1], decline in ecological functions [4], increased frequency of fire [5], lowering of water tables, lower river flow rates and lake levels [1], and soil salinization [5][6][7]. However, the reported evidences that saltcedaris the main or unique cause of these negative effects are ambiguous [3,8].…”