Anne-Mette Hansen's research while affiliated with University of Southern Denmark and other places

... The effect of external disturbances on the internal structure of an ecosystem depends on the properties of the disturbance itself, the size of the disturbance, how it is applied and where in the cycle of population dynamics the disturbance is located. The cyclical pattern that emerged in the simulations was similar to the seasonal cycles that occur in natural ecosystems (Hansen & Jeppesen, 1992;Winder & Cloern, 2010), although the annual cycle of phytoplankton appears in the model in cycles of 5-10 simulated years. This periodicity of inter-decadal variation was also manifested in Lake Veluwemeer's changes in vegetation cover in water between 1950(Scheffer, 1998. ...

... However, hydration cues can also interact with temperature and drive hatching dynamics. In fact, hatching peaks (i.e., higher hatchling abundances) are found at the onset of the wet phase in temperate and subtropical regions (da Silva Bandeira et al., 2020;Hairston et al., 2000). In turn, under constant temperatures and hydration in laboratory, there is evidence for synchronous hatching of dormant stages (Bozelli et al., 2008;Waterkeyn et al., 2013). ...

... Cyclopoid copepods have three foraging patternspredation, scraping and omnivory (Song and Zhang 1979), and smaller cyclopoids tend to be plankton feeders. Food threshold concentrations also differ and are generally higher for advanced stages of cyclopoids than for calanoids (Santer 1994;Hansen and Santer 1995). Besides the impact of changes in fish predation (Jeppesen et al. 2000), a dominance of calanoids in oligotrophic water has been attributed to reduced predation pressure from cyclopoids, which are affected by high cyclopoid nauplii mortality due to low algal densities (Santer 1994;Anneville et al. 2007). ...

... This inference is supported by the high availability of phytoplankton, a food resource for zooplankton, which would not be a limiting resource. Zooplankton densities were suggested to be lower at both low and high macrophyte biomass, since the refuge function is counteracted by the high predation pressure within this vegetation (Jeppesen et al. 1998;Hargeby et al. 2005;Blindow et al. 2014). In Kakel Huincul lake higher macrophyte abundance started to develop ca. ...

... Rotifers, in contrast to larger microcrustaceans, graze on a narrow size window of phytoplankton, leaving them more sensitive to changes in the phytoplankton community (Padial et al. 2012). The lowest level of congruence was generally found for copepods, which is to be expected, as several of the cyclopoid species present in Danish lakes are predators or facultative predators in their advanced stages (Hansen and Jeppesen 1992). These findings are also consistent with previous studies showing weakening congruence in richness of organisms with increasing difference in body sizes in both terrestrial (Sandom et al. 2013) and aquatic (Velghe and Gregory-Eaves 2013) ecosystems. ...

... The development of algal blooms is expected to be a spatially heterogeneous phenomenon Butitta, Carpenter, Loken, Pace, & Stanley, 2017;Pace et al., 2017;Serizawa, Amemiya, & Itoh, 2008) due to both local heterogeneity in nutrient limitation, zooplankton grazing, and temperature (Davis, Berry, Boyer, & Gobler, 2009;Hansen, Andersen, & Jensen, 1997) and population scale heterogeneity due to wind (George & Heaney, 1978). Algal blooms can have a negative effect on ecosystem services, and therefore are often a target for ecosystem monitoring and management. ...

... Winter diapausing is considered to be a common strategy to overcome periods of limited food resources, as well as low temperature and oxygen conditions in Northern European lakes (Elgmork 1980, Elgmork et al. 1990Naess et al. 1993). On the other hand, summer diapause in cyclopoids is seen as a long-term decline in metabolic processes providing encysted or passive dormant stages with the capability to survive in cold and oxygen-depleted deep waters of thermally stratified lakes and avoid food resource limitation and fish predation (George 1973;Gliwicz and Rowan 1984;Wyngaard 1988;Santer and Lampert 1995;Hansen 1996;Santer and Boldt 1998;Kobari and Ban 1998;Santer and Hansen 2006;Alekseev et al. 2007). However, diapausing cyclopoids may suffer from predation by invertebrates, such as chaoborids, that migrate and survive in cold and anoxic deepwater zones. ...

... During hydroperiods, the temporary lakes are inhabited by organisms that developed adaptations allowing them to withstand dry phases, which usually involve dormant or diapause structures (Bruno et al. 2001;Bayly 2001;Wallace et al. 2005), such as the Environmental Research, (ISSN: 0719-3726), 7(3), 2019: 261-280 DOI: http://dx.doi.org/10.7770/safer-V0N0-art1656 263 production of resting eggs (Fryer 1996;Mura & Brecciaroli 2003;Alekseev & Ravera 2004;Schröder 2005), the burial of quiescence individuals in sediments (Hairston & Bohonak 1998;Santer & Hansen 2006), or coming from other lakes (Incagnone et al. 2015). ...

... Gilbert, 1963;Kuo-Cheng Shan, 1974;Pasternak & Arashkevich, 1999) and food limitation (e.g. Scharfenberg, 1910;D'Abramo, 1980;Hansen & Hairston, 1998;Drillet, Hansen & Kiørboe, 2011) as proximate cues. However, given the typically large vertical extent (amplitude) of the migration, it is inexpedient to view most marine SVMs as a behaviour to avoid harmful irradiance or temperature (see also Banse, 1964;Marshall & Orr, 1972). ...

... On one hand, they prey on a wide variety of microorganisms and are major consumers of bacteria, algae, and other protozoa (Šimek et al., 1990;Weisse et al., 1990). On the other hand, ciliates are preyed by various meiobenthos (Hansen, 2000;Kosiba et al., 2017). In addition, microbenthos also competes with meiobenthos due to the food overlapping between them. ...