Non-linear dynamics in marine-phytoplankton population systems

Belgrano, Andrea; Lima, Maurício; Stenseth, Nils Christian

doi:10.3354/meps273281

Cited by 18 publications

(14 citation statements)

References 43 publications

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“…This reveals that there are latent relationships existing between the plankton biotypes, which otherwise were not exposed by numerical abundance and diversity alone. This is in line with Belgrano et al [42] observation that although non-linear density-dependence has been widely used in population dynamics studies, the existences of non-linear exogenous forces have been less explored. Therefore, the formulation of population dynamics models should include both non-linear endogenous and exogenous responses for a better understanding of the effects of natural systems in the environment.…”

Section: Hierarchical Cluster Analysis (Hca)supporting

confidence: 73%

Spatial Fluctuations in Zooplankton Biotypes of the Imo River in a Niger Delta Area of Nigeria

Ogbuagu¹,

Ayoade²

2012

IJE

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The study identified zooplankton biotypes of the increasingly in-stream sand-mined Imo River in Etche, a Delta area of Nigeria, as indicators of the health of the aquatic ecosystem. Plankton samples were collected with a 55µm mesh size plankton net that was hauled horizontally along the river course for 5 minutes at 7 sampling locations once monthly for 24 months (March 2007-February 2009. Samples were fixed/preserved in 4% formalin solution in labelled plastic containers. In the laboratory, a wide-mouthed pipette was used to withdraw 1ml of the plankton subsample and to place it on a Sedge-wick rafter-counting chamber. Standard keys were used for species identifications and counts made through direct microscopy. The ANOVA, post-hoc plots of group means, hierarchical cluster analysis (HCA), and the Margalef's species diversity index were used to analyze data. Zooplankton had low diversity index (0.926 ± 0.100) and was made up of 7 taxa and a mean density of 433 organisms/ml; with order of dominance as Cladocera (25.87%)> Copepoda (20.55%)> Protozoans (19.17%)> Rotifera (18.71%)> fish eggs and larvae (9.24%)> Crab larvae (4.62%)> Beetle larvae (0.69%). Plankton abundance peaked in sampling location 1 (140 organisms/ml; 32.41%) and was least in location 3 (21 organisms/ml; 4.86%), even as there was marked spatial heterogeneity in the taxa composition [F (11.94) >F crit(3.94) ] at P<0.05. The HCA revealed that crab larvae, fish eggs and larvae, beetle larvae, and copepods formed the first and richest cluster, while the rotifers, cladocerans and protozoans formed the sparse 2 nd , 3 rd and 4 th clusters, respectively. The low biotic diversity recorded could be attributed to growth-limiting perturbations created by ongoing in-stream sand mining in water columns.

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Section: Hierarchical Cluster Analysis (Hca)supporting

confidence: 73%

Spatial Fluctuations in Zooplankton Biotypes of the Imo River in a Niger Delta Area of Nigeria

Ogbuagu¹,

Ayoade²

2012

IJE

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“…Some authors have postulated that the densitydependent factors are the true regulators of wild populations (Turchin and Taylor 1992). Nevertheless, at present it is accepted that the population dynamics of wild populations is better understood by attempting to take into account the interaction among endogenous (density-dependents) and exogenous (density-independent) factors (Belgrano et al 2004;Higgings et al1997a, b;Leirs et al 1997;Lima et al 1999;Lima 2001;Lima et al 2000;Murdoch et al 2002;Murúa et al 2003;Royama 1992).…”

Section: Introductionmentioning

confidence: 97%

Population dynamics of two small pelagic fish in the central-south area off Chile: delayed density-dependence and biological interaction

Pedraza-García

Cubillos

2007

Environ Biol Fish

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It is widely believed that environmental variability is the main cause for fluctuations in commercially exploited small pelagic fish populations around the world. Nevertheless, density-dependent factors also can drive population dynamics. In this paper, we analyzed thirteen years of a relative abundance index of two clupeoids fish populations coexisting in the central-south area off Chile, namely the common sardine, Strangomera bentincki, and anchovy, Engraulis ringens. We applied the classical diagnostic tools of time series analysis to the observed time-series. Also, the realized per capita population growth rate was studied with the aim of detecting the feedback structure that is characterizing the population dynamics of the two species. The analysis suggests that population fluctuations of the two species have an important density-dependent component, displaying first-order (direct density-dependent) and secondorder (delayed density-dependent) simultaneously. The density-dependent component explained 70.5 and 55.6 % of the realized per capita population growth rate of common sardine and anchovy, respectively. The deterministic skeleton model showed an asymptotic convergence to equilibrium density. In presence of a stochastic environment, fluctuations were reproduced for the species showing a component of fluctuation with a period of 4 year. The intrinsic dynamics of each species is typical of interacting species resulting from trophic interactions. It is postulated that the second-order dynamics of S. bentincki and E. ringens in central-south Chile, may be the result from interactions with a specialist predator (the fishing fleet), interacting with exogenous environmental factors.

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“…Diversity measures correlate significantly with the North Atlantic Oscillation index. The NAOI (Hurrell 1996) has been used extensively in the analysis of climate-related effects (Beaugrand et al 2002;Belgrano et al 2004a;Blenckner and Hillebrand 2002;Ottersen et al 2001) and integrates a number of important abiotic variables such as temperature and precipitation. A potential problem with any correlative analysis is that temporal shifts in the NAOI co-vary with periods of passive restoration of aquatic habitats from other human impacts.…”

Section: Introductionmentioning

confidence: 99%

Effects of climate-driven temperature changes on the diversity of freshwater macroinvertebrates

2006

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Increasing temperatures due to climate change were found to influence abundance and timing of species in numerous ways. Whereas many studies have investigated climate-induced effects on the phenology and abundance of single species, less is known about climate-driven shifts in the diversity and composition of entire communities. Analyses of long-term data sets provide the potential to reveal such relationships. We analysed time series of entire communities of macrozoobenthos in lakes and streams in Northern Europe. There were no direct linear effects of temperature and climate indices (North Atlantic Oscillation index) on species composition and diversity, but using multivariate statistics we were able to show that trends in average temperature have already had profound impacts on species composition in lakes. These significant temperature signals on species composition were evident even though we analysed comparatively short time periods of 10-15 years. Future climate shifts may thus induce strong variance in community composition.

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Non-linear dynamics in marine-phytoplankton population systems

Cited by 18 publications

References 43 publications

Spatial Fluctuations in Zooplankton Biotypes of the Imo River in a Niger Delta Area of Nigeria

Spatial Fluctuations in Zooplankton Biotypes of the Imo River in a Niger Delta Area of Nigeria

Population dynamics of two small pelagic fish in the central-south area off Chile: delayed density-dependence and biological interaction

Effects of climate-driven temperature changes on the diversity of freshwater macroinvertebrates

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