Zooplankton and phytoplankton relationship

zooplankton and phytoplankton relationship

and of the dominant phytoplankton species, Skeletonema costatum, upon which these copepods are believed to graze preferentially, shows that the seasonal. The zooplankton and phytoplankton pulses are generally considered to be interesting cases are these of the inverse correlation be- tween the density of the . The two main categories of plankton are zooplankton and phytoplankton. Although they are similar in size, inhabit the same bodies of water.

The sampling station was located in the central, deepest point of north-eastern part of the lake.

Water samples for phytoplankton analysis were taken just below the surface. Samples for analyses of chlorophyll a and zooplankton were collected using a 5-L Limnos water sampler every 1 m in a vertical profile.

Difference between Zooplankton and Phytoplankton

Chlorophyll a was assessed with the Lorenzen method after extraction in acetone and corrected for pheopigments a Wetzel and Likens, Number of specimens in 1 mL was counted, assuming as 1 specimen was the cell, coenobium or filament, in dependence on the manner of occurrence.

The biovolume of each species was estimated by applying closest geometric formulae following Hindak Hindak, and Wetzel and Likens Wetzel and Likens, All species were divided into two size groups: Zooplankton biomass was calculated following Bottrell et al. For the calculation of phyto- and zooplankton biomass, ca. Other species were measured occasionally or mean literature data were used.

Zooplankton Vs. Phytoplankton | Sciencing

As the differences among zooplankton data in vertical profile were not statistically significant, mean values were calculated and generally taken into account. The grazing rate of large filter feeders, including Cladocera excluding Leptodora kindtii and Calanoida, was calculated by two models. The second model, proposed by Lampert Lampert,estimated the grazing rate by a function of zooplankton biomass feeding on phytoplankton: Application of those two models allowed the comparison of results based on different parameters characterizing zooplankton.

zooplankton and phytoplankton relationship

Total redundancy indexes, which were calculated in these analyses, were used to estimate how much of the actual variability in one set of variables was explained by the other.

All analysed data were converted to normal distribution. They were also examined to detect possible outliers. As the data of phytoplankton and zooplankton were temperature dependent, they create time-dependent series. Higher values were recorded in spring and summer, and lower in winter.

Differences in abundance were also observed between years. In terms of number of specimens, Cyanobacteria prevailed, accounting on average for The number of Cyanobacteria in summer reached ca.

The most numerous were Pseudanabaena limnetica Lemm. Apart from Cyanobacteria, Chlorophyceae, Bacillariophyceae and Cryptophyceae reached relatively high numbers Fig.

The Relationship between Phytoplankton Evenness and Copepod Abundance in Lake Nansihu, China

Calculated biomass ranged from 5. Cryptophytes accounted for the highest mean contribution However, both species richness and phytoplankton biomass showed no significant relationship with the abundance of copepods. Canonical correspondence analysis revealed that phytoplankton evenness was negatively correlated with Thermocyclops kawamurai, Cyclops vicinus, Eucyclops serrulatus, Mesocyclops leuckarti, Sinocalanus tenellus, Sinocalanus dorrii, Copepods nauplius, but positively correlated with many Cyanophyta species Chroococcus minutus, Dactylococcopsis acicularis, Microcystis incerta, Merismopedia tenuissima, Merismopedia sinica and Lyngbya limnetica.

Based on our results, phytoplankton evenness was a better predictor of copepods abundance in meso-eutrophic lakes. These results provide new insights into the relationship between diversity and ecosystem functioning in aquatic ecosystems. Introduction The Earth ecosystem is experiencing an unprecedented rate of biodiversity loss as a result of global climate change, eutrophication, and overexploitation of natural resources [ 123 ]. Lake ecosystems are relatively vulnerable and the loss of biodiversity may cause catastrophic consequences, such as algae blooms [ 45 ].

Phytoplankton, the most important primary producer in lakes, is particularly sensitive to variations in environmental factors [ 567 ].

The Relationship between Phytoplankton Evenness and Copepod Abundance in Lake Nansihu, China

Understanding the effects of phytoplankton diversity on ecosystem functioning is essential to developing appropriate conservation strategies in aquatic ecosystems [ 58 ]. Aquatic ecosystems are special because their primary organisms i.

Phytoplankton diversity not only impacts the productivity, stability, resource use efficiency measured as the amount of phytoplankton biomass produced per unit of phosphorusand community turnover in its own trophic level [ 8101112 ], but also influences zooplankton through predator-prey interaction [ 1314 ]. It is commonly believed that communities with greater numbers of coexisting species are more resistant to predation [ 13 ].

The increase of producer species richness reduces the predation pressure and leads to smaller predator communities [ 1516 ]. In addition, the relationship between biodiversity and ecosystem functioning varies with different metrics of diversity. For example, Ptacnik et al.

zooplankton and phytoplankton relationship

Therefore, the relationship between producer diversity and predator community is complex and has not reached a consistent conclusion, especially in natural aquatic ecosystems [ 81314 ]. Predator-prey interaction between phytoplankton and zooplankton is an important mechanism in aquatic ecosystems [ 1718 ].

The strength of the interaction is related to the trophic state of the lake: