Search results for "Marine ecology"
showing 10 items of 33 documents
Upwelled plankton community modulates surface bloom succession and nutrient availability in a natural plankton assemblage
2022
Upwelling of nutrient-rich waters into the sunlit surface layer of the ocean supports high primary productivity in eastern boundary upwelling systems (EBUSs). However, subsurface waters contain not only macronutrients (N, P, Si) but also micronutrients, organic matter and seed microbial communities that may modify the response to macronutrient inputs via upwelling. These additional factors are often neglected when investigating upwelling impacts on surface ocean productivity. Here, we investigated how different components of upwelled water (macronutrients, organic nutrients and seed communities) drive the response of surface plankton communities to upwelling in the Peruvian coastal zone. Re…
Cellular effects of bacterial N-3-Oxo-dodecanoyl-L-Homoserine lactone on the sponge Suberites domuncula (Olivi, 1792): insights into an intimate inte…
2014
International audience; Sponges and bacteria have lived together in complex consortia for 700 million years. As filter feeders, sponges prey on bacteria. Nevertheless, some bacteria are associated with sponges in symbiotic relationships. To enable this association, sponges and bacteria are likely to have developed molecular communication systems. These may include molecules such as N-acyl-L-homoserine lactones, produced by Gram-negative bacteria also within sponges. In this study, we examined the role of N-3-oxododecanoyl-L-homoserine lactone (3-oxo-C12-HSL) on the expression of immune and apoptotic genes of the host sponge Suberites domuncula. This molecule seemed to inhibit the sponge inn…
Limnogēno purvu veģetācija Latvijā
2006
Advisor: Pakalne, Māra
Functional Redundancy and Complementarities of Seed Dispersal by the Last Neotropical Megafrugivores
2013
Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:28:22Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:42:48Z : No. of bitstreams: 1 2-s2.0-84873586375.pdf: 1508075 bytes, checksum: 7e697f6c67a83195e9b0cb525355980e (MD5) Made available in DSpace on 2014-05-27T11:28:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-07 Background: Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. Th…
Altered epiphyte community and sea urchin diet in Posidonia oceanica meadows in the vicinity of volcanic CO2 vents
2017
Ocean acidification (OA) predicted for 2100 is expected to shift seagrass epiphyte communities towards the dominance of more tolerant non-calcifying taxa. However, little is known about the indirect effects of such changes on food provision to key seagrass consumers. We found that epiphyte communities of the seagrass Posidonia oceanica in two naturally acidified sites (i.e. north and south sides of a volcanic CO2 vent) and in a control site away from the vent at the Ischia Island (NW Mediterranean Sea) significantly differed in composition and abundance. Such differences involved a higher abundance of non-calcareous crustose brown algae and a decline of calcifying polychaetes in both acidif…
Modeling Macroalgal Forest Distribution at Mediterranean Scale: Present Status, Drivers of Changes and Insights for Conservation and Management
2020
Macroalgal forests are one of the most productive and valuable marine ecosystems, but yet strongly exposed to fragmentation and loss. Detailed large-scale information on their distribution is largely lacking, hindering conservation initiatives. In this study, a systematic effort to combine spatial data on Cystoseira C. Agardh canopies (Fucales, Phaeophyta) was carried out to develop a Habitat Suitability Model (HSM) at Mediterranean scale, providing critical tools to improve site prioritization for their management, restoration and protection. A georeferenced database on the occurrence of 20 Cystoseira species was produced collecting all the available information from published and grey lit…
Long-Term Coexistence of Rotifer Cryptic Species
2011
Despite their high morphological similarity, cryptic species often coexist in aquatic habitats presenting a challenge in the framework of niche differentiation theory and coexistence mechanisms. Here we use a rotifer species complex inhabiting highly unpredictable and fluctuating salt lakes to gain insights into the mechanisms involved in stable coexistence in cryptic species. We combined molecular barcoding surveys of planktonic populations and paleogenetic analysis of diapausing eggs to reconstruct the current and historical coexistence dynamics of two highly morphologically similar rotifer species, B. plicatilis and B. manjavacas. In addition, we carried out laboratory experiments using …
Vides pH ietekme sūnu sporu dīgšanā un sūnaugu attīstībā
1939
Latvijas purvu veģetācijas klasifikācija un dinamika
1998
Rakstu krājumā apkopoti pēdējo gadu Latvijas purvu un ezeru krastu veģetācijas pētījumu rezultāti. Analizēti Teiču purva veidošanās apstākļi pēc putekšņu diagrammām. Publicētas purvu augu sabiedrību sintaksonomijas shēmas un sinoptiskās tabulas.
Reto un izzūdošo Latvijas savvaļas orhideju bioloģiskās īpatnības in situ un in vitro
2012
Promocijas darbs (publikāciju kopa) tika izstrādāts V/a „Nacionālais Botāniskais dārzs Augu valsts bioloģiskās daudzveidības in vitro saglabāšanas nodaļā laika posmā no 2008. līdz 2011. gadam. Ģenētiskie pētījumi tika veikti LU Bioloģijas institūta Augu Ģenētikas laboratorijā 2010. un 2012. gadā.