Microsatellite polymorphism in the edaphic spruce, Picea asperata, originating from the mountains of China

Abstract

Nutrient enrichment and water depth modify consumer control in rocky shore macroalgal communities

The objective of my thesis is to assess mechanisms of ecological community control in macroalgal communities in the Baltic Sea. In the top-down model, predatory fish feed on invertebrate mesograzers, releasing algae partly from grazing pressure. Such a reciprocal relationship is called trophic cascade. In the bottom-up model, nutrients increase biomass in the food chain. The nutrients are first assimilated by algae and, via food chain, increase also abundance of grazers and predators. Previous studies on oceanic shores have described these two regulative mechanisms in the grazer - alga link, but how they interact in the trophic cascades from fish to algae is still inadequately known. Because the top-down and bottom-up mechanisms are predicted to depend on environmental disturbances, such as wave stress and light, I have studied these models at two distinct water depths. There are five factorial field experiments behind the thesis, which were all conducted in the Finnish Archipelago Sea. In all the experiments, I studied macroalgal colonization - either density, filament length or biomass - on submerged colonization substrates. By excluding predatory fish and mesograzers from the algal communities, the studies compared the strength of the top-down control to natural algal communities. A part of the experimental units were, in addition, exposed to enriched nitrogen and phosphorus concentrations, which enabled testing of bottom-up control. These two models of community control were further investigated in shallow (<1 m) and deep (ca. 3 m) water. Moreover, the control mechanisms were also expected to depend on grazer species. Therefore different grazer species were enclosed into experimental units and their impacts on macroalgal communities were followed specifically. The community control in the Baltic rocky shores was found to follow theoretical predictions, which have not been confirmed by field studies before. Predatory fish limited grazing impact, which was seen as denser algal communities and longer algal filaments. Nutrient enrichment increased density and filament length of annual algae and, thus, changed the species composition of the algal community. The perennial alga Fucus vesiculosusA and the red alga Ceramium tenuicorne suffered from the increased nutrient availabilities. The enriched nutrient conditions led to denser grazer fauna, thereby causing strong top-down control over both the annual and perennial macroalgae. The strength of the top-down control seemed to depend on the density and diversity of grazers and predators as well as on the species composition of macroalgal assemblages. The nutrient enrichment led to, however, weaker limiting impact of predatory fish on grazer fauna, because fish stocks did not respond as quickly to enhanced resources in the environment as the invertebrate fauna. According to environmental stress model, environmental disturbances weaken the top-down control. For example, on a wave-exposed shore, wave stress causes more stress to animals close to the surface than deeper on the shore. Mesograzers were efficient consumers at both the depths, while predation by fish was weaker in shallow water. Thus, the results supported the environmental stress model, which predicts that environmental disturbance affects stronger the higher a species is in the food chain. This thesis assessed the mechanisms of community control in three-level food chains and did not take into account higher predators. Such predators in the Baltic Sea are, for example, cormorant, seals, white-tailed sea eagle, cod and salmon. All these predatory species were recently or are currently under intensive fishing, hunting and persecution, and their stocks have only recently increased in the region. Therefore, it is possible that future densities of top predators may yet alter the strengths of the controlling mechanisms in the Baltic littoral zone.

Fugue in G minor : Little

Soitinnus: Urut

The little organ book

Ennen jokaista preludia esitetään koraali johon kyseinen preludi perustuu.

Sotilaiden epäviralliset ryhmänormit kolmessa jalkaväkikomppaniaa koskevassa empiirisessä tutkimuksessa (Knut Pipping, Roger Little, John Hockey)

Tutkimuksessa oli tavoitteena selvittää, millaisia sotilaiden epävirallisia ryhmänormeja tutkijat ovat havainneet eräissä sotilasyksiköissä jotka ovat toimineet sodassa tai sodan olosuhteita osittain vastanneissa tilanteissa. Keskeisinä lähteinä käytetään seuraavia kolmea sotilasyksikköön kohdistunutta tutkimusta: - Knut Pipping: "Kompaniet som samhälle Iakttagelser i ett finskt frontförband 1941-1944" (1947), suomenkielinen laitos ”Komppania pienoisyhteiskuntana” (1978), englanninkielinen laitos ”Infantry Company as a Society” (2008) - Roger W. Little: “Buddy Relations and Combat Performance” (1964) ja sen perustana ollut Littlen väitöskirja “A Study of the relationship between collective solidarity and combat role performance” (1955) - John Hockey: "Squaddies Portrait of a Subculture" (1986). Tutkimusongelmat olivat seuraavat: 1) Millaisia sotilaiden epävirallisia ryhmänormeja tai virallisista normeista poikkeavia käyttäytymismuotoja esiintyi kolmessa sodan ajan tai poikkeusolojen sotilasyksikössä Knut Pippingin, Roger Littlen ja John Hockeyn komppanioita koskeneiden tutkimusten mukaan? 2) Esiintyikö ao. tutkimuksissa (sotilasyksiköissä) samansisältöisiä tai edes suunnilleen samansisältöisiä normeja tai virallisista normeista poikkeavia käyttäytymismuotoja? Tutkimusmenetelmänä on Pippingin, Littlen ja Hockeyn tutkimusten ja tutkimustulosten systemaattinen läpikäynti ja vertailu sen selvittämiseksi, millaisia epävirallisia normeja kohteena olleissa sotilasyksiköissä on havaittu. Kohteina olevat tutkimukset käytiin läpi seuraavan skeeman mukaisesti: - sotilasyksikön virallinen organisaatio ml. viralliset johtajat - sotilasyksikön henkilöstö - sotilasyksikön toimintaympäristö ja tehtävät tutkimusajankohtana - sotilasyksikön sosiaaliset ryhmät - sotilasyksikössä havaittuja epävirallisia normeja. Tutkimuksessa tuli ilmi, että tutkituissa sotilasyksiköissä esiintyi joitakin samantyyppisiä epävirallisia normeja siitä huolimatta, että sotilasyksiköt olivat eri maista ja toimivat eri vuosikymmeninä ja erilaisissa sodissa ja tilanteissa. Sotilasyksiköissä havaittiin mm., että: - miehistöön kuuluvat sotilaat katsoivat, että heille annetut vaarallisetkin tehtävät, ainakin järkeviksi katsotut, piti hoitaa ainakin jollakin minimitasolla ja kaikkien piti osallistua tähän - miehistötasolla sotilaiden piti ainakin tietynlaisissa tilanteissa olla lojaaleja toisille samanarvoisille tai ainakin lähipiirissä oleville - lähipiirin sotilaihin kohdistuva lojaalisuus saattoi ohittaa viralliseen organisaatioon kohdistuvat velvoitteet - kaikissa yksiköissä esiintyi taistelussa käyttäytymistä koskevia epävirallisia normeja; esimerkiksi "liiallista rohkeutta" ei hyväksytty - joissakin tilanteissa vaaralliseen tilanteeseen liittyvän normin noudattaminen lisäsi yksittäiseen sotilaaseen kohdistuvaa välitöntä hengenvaaraa - lähipiirissä olevien sotilaiden henkilökohtaiseen omaisuuteen tai varusesineisiin ei saanut kajota - sen sijaan suhtautuminen muuhun valtion omaisuuteen oli liberaalimpaa.

Climbing in the Arctic Mountains

kuv., 10 x 22 cm

Macroalgae across environmental gradients : tools for managing rocky coastal areas of the northern Baltic Sea

Macroalgae are the main primary producers of the temperate rocky shores providing a three-dimensional habitat, food and nursery grounds for many other species. During the past decades, the state of the coastal waters has deteriorated due to increasing human pressures, resulting in dramatic changes in coastal ecosystems, including macroalgal communities. To reverse the deterioration of the European seas, the EU has adopted the Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD), aiming at improved status of the coastal waters and the marine environment. Further, the Habitats Directive (HD) calls for the protection of important habitats and species (many of which are marine) and the Maritime Spatial Planning Directive for sustainability in the use of resources and human activities at sea and by the coasts. To efficiently protect important marine habitats and communities, we need knowledge on their spatial distribution. Ecological knowledge is also needed to assess the status of the marine areas by involving biological indicators, as required by the WFD and the MSFD; knowledge on how biota changes with human-induced pressures is essential, but to reliably assess change, we need also to know how biotic communities vary over natural environmental gradients. This is especially important in sea areas such as the Baltic Sea, where the natural environmental gradients create substantial differences in biota between areas. In this thesis, I studied the variation occurring in macroalgal communities across the environmental gradients of the northern Baltic Sea, including eutrophication induced changes. The aim was to produce knowledge to support the reliable use of macroalgae as indicators of ecological status of the marine areas and to test practical metrics that could potentially be used in status assessments. Further, the aim was to develop a methodology for mapping the HD Annex I habitat reefs, using the best available data on geology and bathymetry. The results showed that the large-scale variation in the macroalgal community composition of the northern Baltic Sea is largely driven by salinity and exposure. Exposure is important also on smaller spatial scales, affecting species occurrence, community structure and depth penetration of algae. Consequently, the natural variability complicates the use of macroalgae as indicators of human-induced changes. Of the studied indicators, the number of perennial algal species, the perennial cover, the fraction of annual algae, and the lower limit of occurrence of red and brown perennial algae showed potential as usable indicators of ecological status. However, the cumulated cover of algae, commonly used as an indicator in the fully marine environments, showed low responses to eutrophication in the area. Although the mere occurrence of perennial algae did not show clear indicator potential, a distinct discrepancy in the occurrence of bladderwrack, Fucus vesiculosus, was found between two areas with differing eutrophication history, the Bothnian Sea and the Archipelago Sea. The absence of Fucus from many potential sites in the outer Archipelago Sea is likely due to its inability to recover from its disappearance from the area 30-40 years ago, highlighting the importance of past events in macroalgal occurrence. The methodology presented for mapping the potential distribution and the ecological value of reefs showed, that relatively high accuracy in mapping can be achieved by combining existing available data, and the maps produced serve as valuable background information for more detailed surveys. Taken together, the results of the theses contribute significantly to the knowledge on macroalgal communities of the northern Baltic Sea that can be directly applied in various management contexts.

A new map of Denmark, Norway, Sweden, & Moscovy shewing their present general divisions, cheif, [!] cities or towns, rivers, mountains, &c.

[N. 1:8500000].

Little Red Riding Hood

Kuvitusta satuun Punahilkka.