Time and Space Issues in Ecotoxicology: Population Models, Landscape Pattern Analysis, and Long-Range Environmental Chemistry

Abstract

Advances in ecotoxicology addressing problems of time and spatial scales are presented and interpreted in the frame of concepts on population/community dynamics and landscape pattern analysis. Example deterministic/probabilistic modeling experiments are used to illustrate key concepts. Space and time scales analyzed are single and multigenerations of local populations, metapopulations, community, and ecosystem/landscape. Most population models used in recent ecotoxicology studies are deterministic and do not include a formal treatment of spatial processes, like migration or local random extinction. Some metapopulation models have been applied with success. Upscaling of ecotoxicological results at the community level is less developed, probably because of the inherent complexity of indirect and direct coactions among organisms. Community and ecosystem toxicity end points that could find a broad use in regulatory applications have not yet been identified. Some practical issues like the estimation of the potential for the natural attenuation of toxicity and the transport of contaminants along food chains must be addressed at these scales/levels of biological complexity. The estimation of ecotoxicological effects has been increasingly evolving to integrate modeling and monitoring contaminant transport and fate, landscape pattern analysis, and spatially explicit population dynamics (including direct and indirect communal interactions).

Assessing contaminated sediments in the context of multiple stressors

“…Moreover, different macroalgal species accumulated contaminants to different degrees within the same site, creating a patchwork of varying contamination loads that organisms could choose from. We will advance our ability to predict the effects of heterogeneously distributed contaminants as we develop the field of landscape ecotoxicology 299, and this may be possible with existing data sets.…”

Determinação de Pesticidas na Água e Sedimento do Rio Piquiri

“…Os fatores que alteram a mobilidade e persistência dos agroquímicos estão relacionados ao regime de chuvas, intensidade do escoamento das águas superficiais, média do regime térmico, entre outros (NAVARRO et al, 2011). Por sua vez, a vulnerabilidade dos organismos não alvos depende da estrutura espacial e distribuição da biodiversidade da área (ARES, 2003).…”

Life‐history phenology strongly influences population vulnerability to toxicants: A case study with the mudsnail Potamopyrgus antipodarum

“…A large number of studies have demonstrated the value of using demographic models in an ecotoxicological context (reviewed in Galic et al ). However, despite attempts to use more elaborate modeling approaches that integrate environmental complexity , the ecological relevance of the population models involved is generally low. In fact, in the great majority of studies, demographic models are based on laboratory assays with species that are not representative of the ecosystems of interest (e.g., tropical fishes or daphnids for studies on lotic and temperate systems).…”

“…In fact, the determinants of demographic sensitivity of populations are subject to strong variability (e.g., interspecies and interpopulation variability of life cycle). This variability cannot be taken into account with overly simple demographic models . Notably, these models do not capture the seasonal variability of population dynamics, even though several studies have stressed the seasonal variability of population vulnerability.…”