Trace element content and molecular biodiversity in the epiphytic moss Leptodon smithii: Two independent tracers of human disturbance

Metal and metalloid speciation in plants: Overview, instrumentation, approaches and commonly assessed elements

“…Spagnuolo et al [56] found that nitrogen air jets were too aggressive for the cleaning of mosses at higher pressures (4-8 bars) and were unable to remove adhering particles at lower pressures [56] and results were found to be irreproducible and unpredictable. In comparison, the use of ultrasonic probes for cleaning procedures was found to produce reproducible data and ensured the integrity of the cell membrane [56]. The procedural requirements for immersing the sample in a liquid phase however, was found to encourage the leaching of metals from the sample, compromising the quality of the results [56].…”

“…A solid sample is placed into a solution and is exposed to ultrasonic energy, which results in the formation of imploding bubbles, leading to high localized temperatures and pressures [79]. In this way compounds or elements can be extracted from the sample matrix [56]. Ultrasonic methods also increase the rate of reaction in sequential extractions [78] and assist with the homogenous suspension and distribution of slurries [80].…”

“…In comparison, the use of ultrasonic probes for cleaning procedures was found to produce reproducible data and ensured the integrity of the cell membrane [56]. The procedural requirements for immersing the sample in a liquid phase however, was found to encourage the leaching of metals from the sample, compromising the quality of the results [56]. Ultrasonic baths have also been used as a gentler alternative to ultrasonic probes, and have been used to clean foliose lichens such as Parmelia sulcata [57].…”

“…Some samples, such as mosses, are especially porous and as a result are difficult to clean effectively [56], and so a number of techniques have been employed to remedy this. Spagnuolo et al [56] found that nitrogen air jets were too aggressive for the cleaning of mosses at higher pressures (4-8 bars) and were unable to remove adhering particles at lower pressures [56] and results were found to be irreproducible and unpredictable. In comparison, the use of ultrasonic probes for cleaning procedures was found to produce reproducible data and ensured the integrity of the cell membrane [56].…”

Disturbance and change in biodiversity

“…Effects of disturbance on biodiversity have been studied in a great variety of ecosystems ranging from tundra communities (Jorgenson et al 2010) to coral reefs (Graham et al 2009), a range of organisms extending from bacteria (Binh et al 2007) to primates (Bicknell & Peres 2010) and at multiple levels of organization including molecular pathways (Spagnuolo et al 2009) and ecosystem functioning (Hotes et al 2010). The types of disturbance involved include everything from single tree-falls (Brokaw 1985) to ecological catastrophes (Hughes 1994).…”