Young ISDR

(image from here ) VELEZ, M.I., JARAMILLO, C., SALAZAR, F.,  BENITO, X ., FRITZ, S., TAPIA, P., LUBINIECKI, D., KAR., N. & ESCOBAR, J . 2017.   Aquatic ecosystems in a newly formed ecospace: Early Pliocene lakes in the Central Andean Altiplano.  Palaeogeography, Palaeoclimatology, Palaeoecology   Uplift of the Altiplano in the Central Andes of South America had profound effects on land, oceans and atmosphere. Very little, however, is known about the ecosystems that developed on the ecospaces first formed once the Altiplano reached its present high altitude . We present a micropaleontological (diatoms and ostracods) and stratigraphic analysis of Pliocene Member C of the El Descanso Formation that outcrops near the town of Yaurí, Perú . Lithofacies analysis indicates that fluvial conditions were eventually replaced by several lacustrine and marsh environments. Diatom and ostracod assemblages indicate that these bodies ...

(from here ) TAMMELIN, M. & KAUPPILA, T . 2018.   Quaternary landforms and basin morphology control the natural eutrophy of boreal lakes and their sensitivity to anthropogenic forcing. Frontiers in Ecology and Evolution 6:65. doi: 10.3389/fevo.2018.00065 Both natural and anthropogenic changes in boreal lakes have been studied utilizing paleolimnological methods, but the spatial variation in the natural conditions of lakes and its connection to geological factors has drawn less attention. Our aims were to examine the spatial distribution of naturally eutrophic lakes on the previously glaciated terrain of central-eastern Finland and the relationship between pre-human disturbance water quality and geological factors related to the basins and their catchments. Furthermore, we studied the pre- to post-human disturbance changes in the diatom assemblages and water quality of 48 lakes (51 sampling sites) across the pre-disturbance phosphorus gradie...

BENITO, X. , TROBAJO, R. & IBÁÑEZ, C. 2015.  Benthic diatoms in a Mediterranean delta: ecological indicators and a conductivity transfer function for paleoenvironmental studies.  Journal of Paleolimnology  54: 171–188  The contemporary distribution of benthic diatoms and their use as ecological indicators were examined in a coastal wetland, the Ebro Delta, as a representative of environmental conditions in Mediterranean coastal wetlands. A total of 424 diatom taxa were identified across 24 sites encompassing a wide range of wetland habitat types (coastal lagoons, salt and brackish marshes, shallow bays, microbial mats and nearshore marine waters) and conductivities. Canonical correspondence analysis showed that water conductivity and water depth were the main factors structuring the diatom assemblages. Cluster analysis identified five habitat types according to the similarity in diatom species composition: salt marshes, brackish marshes, ...

Melina Feitl writes about links between diatom valve size and climate  variability Why  Pantocsekiella ocellata ? Diatoms are widely used proxies for reconstructing past climatic and environmental change because of their ecological sensitivity to physical and chemical lake characteristics [1]. These fossil reconstructions are often based on the known ecological ranges of modern taxa.  The Arctic, although particularly interesting climatically, has relatively sparse studies on diatom taxonomy, ecology, and biogeography because of logistical issues involving its remote location.  One of the most important members of the Arctic (and sub-arctic) diatom flora is the planktic species  Pantocsekiella ocellata  (Pantocsek) K.T. Kiss & E. Ács, formerly reported as  Cyclotella ocellata  Pantocsek.   P. ocellata  was first described by Pantocsek in 1902; valves were circular with a marginal ring of striae and a...

by Heather  Moorhouse* The tropical diatom genus Afrocymbella has only 12 known species, all of which are found in the African Rift Valley lakes 1 . They have been observed both free-living in the water column and attached to rocks and plants, and are solitary or colonial 1 . One such species is Afrocymbella barkeri Cocquyt & Ryken sp. nov. (19.9-63.8 µm) (Fig. 1), a newly described diatom found in Lake Chala 1  (Fig. 2) , a tropical crater lake that lies directly on the border of Kenya and Tanzania , just south of the equator  (Fig. 3) .  This species was named after Prof. Philip Barker whose seminal work on diatoms in the East African Rift valley lakes has helped understand past climate and environmental change in the region. Afrocymbella barkeri is common at the end of the dry and windy season in Lake Chala, which corresponds to the northern hemisphere summer. The summer winds mix the lake water column and cause nutrient-rich deep water to rise to t...