Sampling of Aquatic and Terrestrial Invertebrates in Wetlands

ANDERSON JIM; ZILLI FLORENCIA; MARCHESE MERCEDES ROSA; MONTALTO LUCIANA; MCKINNEY MATTHEW; YONG-LAK PARK

Wetland Techniques

SPRINGER

Año: 2011;

The sampling design is the key in any research. The bias of the results and conclusions and the success of the study depend on the sampling techniques and sampling designs employed. There is a high diversity of invertebrates and a high diversity of habitats and, then the samples can be collected by a range of different methods and it is not always easy to define the best. However it is important to determine the optimal methods needed according the objectives of the study. Linked with the survey objectives, details of subsequent statistical analyses to be applied and needs for comparison with other studies must also be assessed in the planning phase (Keith 1991). The clumped distribution of populations may be related to unevenly distribution of environmental factors and microhabitat preference of invertebrates. Furthermore, it may also depend on the natural tendency of some species to aggregate and thus produce a contagious distribution without the influence of environmental factors (Elliott 1977). The benthic sampling will depend on the invertebrate distribution, and the number, spacing and timing of sample sets should be carefully determined in relation to the aim of the study and the predetermined variability between samples taken from established zones of the environments. The sampling needs to be designed in relation to available sampling methods, the duration of the study, and the levels of taxonomic and ecological analysis necessary to answer specific and focused questions. These depend on the available funding, type of habits and the expertise of the researchers. In the Figure 1, a general planning procedure and organization of a benthos study is showed.