Factors Influencing the Distribution of Phytoplankton in 97 Headwater Lakes in Insular Newfoundland

Abstract

1987. Factors influencing the distribution of phytoplankton in $7 headwater lakes in insular Newfoundland. Can. ). Fish. Aquat. Sci. 44: 639-649.Phytoplankton samples collected from 97 headwater lakes throughout insular Newfoundland were analyzed and used as a basis for a statistical evaluation of the environmental factors influencing species distributions. A selected subset of 77 taxa were clustered using a complete-linkage cluster analysis. The final 12 clusters represent the associations of species found occurring together in insular Newfoundland. Physical, chemical, and morphometric data collected with the phytoplankton served to characterize the environment. Factor analysis simplified the original variables, many of which were highly correlated and uninterpretable, into seven derived environmental factors: dystrophy, hardness, salinity, lake size, season, watershed influence, and orthophosphate enrichment. The resulting orthogonal B y rotated (VAWI MAX) scores comprising these seven factors were correlated with species abundances. Spearman correlations showed several relationships between species distributions and the seven derived environmental factors. Although the analysis identified a subset of naturally acidic, dystrophic lakes, it failed to reveal any evidence of anthropogenic acidification in the lakes studied. For the most part, the members from each of the cluster groups demonstrated similar relationships with the derived environmental factors. The evidence suggests that the cluster groups may represent species associations; groups of species that co-occur because of their common requirements for specific environmental conditions. Phytoplankton autecological findings resulting from this study of insular Newfoundland lakes correspond well with conclusions derived independently from a comparable study of 95 headwater lakes in Labrador.Des echantillons de phytoplancton recueillis dans 97 lacs d'amont de Terre-Neuve ont et6 analyses et utilises comme base pour une evaluation statistique des factel-~rs environnementaux qui influent sur la repartition des esp6ces. Un sous-ensemble de 77 taxons a kt6 group4 I'aide d'une analyse en grappes int6gration complete. Les 12 groupes obtenus representent les associations des espPces vivant ensemble dans Bes eaux de Terre-Neuve.Les donnees physiques, chimiques et morphom6triques recueislies avec le phytoplancton ont servi a la caracterisation de l'environnement. L'analyse des facteurs a simplifie les variables originales dont un grand nombre 4taient fortement correlees et impossibles 3. interpreter; on a ainsi obtenu sept facteurs environnementaux d6rives : dystrsphie, duretk, salinite, superficie du lac, saison, influence du bassin versant et enrichissement a B'ot-thophosphate. Les pointages obtenus (VAWIMAX) de ces sept facteurs, ii rotation a angle droit, etaient correles a l'abndance des eskces. Les coefficients de correlation des rangs de Spearman ont revel6 piusieurs relations entre les repartitions des especes et les sept facteurs environnementaux dkriv6s. Qu...

Relationship between abundance of N2-fixing cyanobacteria and environmental features of Spanish rice fields

“…Many authors found a direct relationship between cyanobacterial presence and the mineralization variables (Ca, hardness, etc.) as we have [4]. These results may be explained by the high Ca requirements of many Nz-fixing cyanobacteria [21].…”

Ecological characteristics of the freshwater Ostracoda in Bolu Region (Turkey)

“…Similar association was documented in a different taxonomic group. Earle et al (1987), for example, reported that clustering groups of 77 phytoplankton taxa collected from 97 headwater lakes in Newfoundland (Canada) were based on specific environmental requirements of species. Our results support their findings.…”

Seasonal patterns of total and energy reserve lipids of dominant zooplanktonic crustaceans from a hyper-eutrophic lake

“…Except for a few cases, algae were usually identified to species level. A combined minimum of 500 cells, colonies, and filaments were counted per sample as in Earle et al (1987). Counts were expressed as wet biomass (rag/m3).…”