Shifts in phytoplankton species richness and biomass along a latitudinal gradient – consequences for relationships between biodiversity and ecosystem functioning

Abstract

Summary 1. Analysing phytoplankton community data from 205 small, mainly oligotrophic Swedish lakes along a 13° latitudinal gradient, we found that the duration of the open‐water season (DT > 0) was best related to phytoplankton species richness and biomass, probably because DT > 0 can be used as a proxy for nutrient concentrations, as well as for light and temperature conditions in lakes. 2. The relationships between DT > 0 and phytoplankton species richness and biomass were not linear but showed significant shifts, that is, richness suddenly doubled at DT > 0 = 170 days and phytoplankton biomass began to strongly increase at DT > 0 around 220 days. 3. The doubling in species richness corresponded to a change in the seasonal plankton succession from one to two peaks per year, and the shift in biomass corresponded to a shift in nutrient concentrations. 4. The geographical differences in richness and biomass shifts resulted in an exponential biodiversity–ecosystem functioning relationship along a DT > 0 gradient. 5. We conclude that phytoplankton species richness and biomass are driven by different environmental factors, resulting in a nonlinear biodiversity–ecosystem functioning relationship. The shape of the diversity–functioning relationship varies along with variations in environmental drivers, which is of highest importance for ongoing discussions about impacts of global change on biodiversity and ecosystem functioning.

Plankton Community Stability and Its Relationship with Phytoplankton Species Richness in Lake Nansihu, China

“…Aquatic ecosystems are unique, and the stabilization of their main organisms, phytoplankton and zooplankton, has been found to be influenced by variations in producer diversity [5,6]. Thus, studies on the diversity-stability relationship in plankton communities are essential to developing appropriate conservation strategies in aquatic ecosystems [7,8].…”

Perspectives on the use of lakes and ponds as model systems for macroecological research

“…To date more than thirty hypotheses have been proposed to explain this pattern (see Willig et al, 2003; for a review), and according to Mittelbach et al (2007) they can be grouped into three main types: i) ecological hypotheses focused on the maintenance of diversity, mainly due to higher energy input (or productivity) (Weyhenmeyer et al, 2013); ii) historical hypotheses which sustain that the extent and duration of tropical climate on the Earth's history allowed longer time for the species to diversify and accumulate (Hawkins et al, 2007); and iii) evolutionary hypotheses which propose higher diversification rates in the tropics (Allen and Gillooly, 2006). Grouped within the historical hypotheses, the effect of Pleistocene glaciations on current richness gradients deserves an especial mention.…”

“…This is in agreement to the perspective that no single mechanism is enough to account for the origin of geographical diversity gradients . Nonetheless, there is large body of evidence on the determinants of species diversity and community structure in lakes (Amarasinghe and Welcomme, 2002;Fallu et al, 2002;Rosenfield, 2002;Hessen et al, 2006;Lappalainen and Soininen, 2006;Mehner et al, 2007;Muylaert et al, 2010;Olden et al, 2010;Collen et al, 2013;Weyhenmeyer et al, 2013). Despite the multiplicity of hypotheses and groups, formal meta-analyses (or informal ones, such as Stendera et al, 2012) may allow identifying the main general drivers of lake diversity.…”

Effects of Environmental Factors on the Temporal Stability of Phytoplankton Biomass in a Eutrophic Man-Made Lake

“…Phytoplankton is the most important primary producer in aquatic ecosystems and it is characterized by a short generation time and efficient trophic transfer, and is sensitive to the variations of environmental factors [1][2][3][4]. Recently, more and more lakes face eutrophication caused by human activities and global climate warming [5][6][7][8][9].…”

“…Recently, more and more lakes face eutrophication caused by human activities and global climate warming [5][6][7][8][9]. As a result, catastrophic consequences such as species turnover and algae blooms are common in aquatic ecosystems [3,5,6,10]. Thus, studies on the stability of phytoplankton community and its influencing factors are essential to develop appropriate conservation strategies in aquatic ecosystems [11][12][13][14].…”