Browsing by Subject "species"

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  • Hekkala, Toni (Helsingin yliopisto, 2019)
    Arsenic (As) is a metalloid naturally present in the environment. Arsenic species vary in toxicity. Metal mining has contributed to the anthropogenic input of arsenic to groundwaters and surface waters. In this study, water samples were collected from 20 sample points in three mining-impacted study areas in Finland: the former Ylöjärvi Cu–W–As and Haveri Au–Cu mines, and the active Pyhäsalmi Zn–Cu mine. Six groundwater well samples, eleven surface water samples and three tailings seepage collection ditch samples were analyzed for dissolved arsenic speciation by HPLC-ICP-MS and for geochemical composition by ICP-MS, titration, and ion chromatography. Dissolved arsenic concentrations ranged from 14.2 to 6649 µg L-1 in samples collected at the Ylöjärvi study area, from 0.5 to 6.2 µg L-1 in samples collected at the Haveri study area, and from 0.2 to 9.4 µg L-1 in samples collected at the Pyhäsalmi study area. In all study areas, measured dissolved arsenic concentrations showed a general decrease from the tailings to the surroundings. Speciation analysis showed that two of the samples collected at the Ylöjärvi study area had arsenite [As(III)] as the dominant form of dissolved inorganic arsenic (iAs), three had arsenate [As(V)] as the dominant form of dissolved iAs, and four had a mixture of both. In the water samples collected at the Haveri and Pyhäsalmi study areas, all concentrations of dissolved arsenic species were below method detection limits. Also, none of the 22 water samples analyzed for arsenic speciation had dissolved MMA or DMA concentrations above method detection limits. Identification of dissolved arsenic species in the sampled waters in Haveri and Pyhäsalmi, and of MMA and DMA in all sampled waters requires more detailed study. A significant 2-tailed Pearson correlation between dissolved arsenic and dissolved molybdenum (Mo) (r=0.80**, n=20), and dissolved arsenic and dissolved potassium (K) (0.68**, n=19) suggests that in these three study areas the distributions of dissolved arsenic and Mo, as well as dissolved arsenic and K may be controlled by the same environmental variables. Anomalously high maximum concentrations of dissolved Al, Ca, Co, Cu, Fe, Ni, and SO4 were measured in surface water samples collected at the Ylöjärvi and Haveri study areas, and in a seepage collection ditch sample collected at the Pyhäsalmi study area.
  • Camarena‐Gómez, María Teresa; Ruiz‐González, Clara; Piiparinen, Jonna; Lipsewers, Tobias; Sobrino, Cristina; Logares, Ramiro; Spilling, Kristian (American Society of Limnology and Oceanography, 2021)
    Limnology and Oceanography 66: 1, 255-271
    In parts of the Baltic Sea, the phytoplankton spring bloom communities, commonly dominated by diatoms, are shifting toward the co-occurrence of diatoms and dinoflagellates. Although phytoplankton are known to shape the composition and function of associated bacterioplankton communities, the potential bacterial responses to such a decrease of diatoms are unknown. Here we explored the changes in bacterial communities and heterotrophic production during the spring bloom in four consecutive spring blooms across several sub-basins of the Baltic Sea and related them to changes in environmental variables and in phytoplankton community structure. The taxonomic structure of bacterioplankton assemblages was partially explained by salinity and temperature but also linked to the phytoplankton community. Higher carbon biomass of the diatoms Achnanthes taeniata, Skeletonema marinoi, Thalassiosira levanderi, and Chaetoceros spp. was associated with more diverse bacterial communities dominated by copiotrophic bacteria (Flavobacteriia, Gammaproteobacteria, and Betaproteobacteria) and higher bacterial production. During dinoflagellate dominance, bacterial production was low and bacterial communities were dominated by Alphaproteobacteria, mainly SAR11. Our results suggest that increases in dinoflagellate abundance during the spring bloom will largely affect the structuring and functioning of the associated bacterial communities. This could decrease pelagic remineralization of organic matter and possibly affect the bacterial grazers communities.
  • Sörenson, Eva; Bertos-Fortis, Mireia; Farnelid, Hanna; Kremp, Anke; Krüger, Karen; Lindehoff, Elin; Legrand, Catherine (Wiley & Sons, 2019)
    Environmental Microbiology Reports, 11: 425-433
    Phytoplankton and bacteria interactions have a significant role in aquatic ecosystem functioning. Associations can range from mutualistic to parasitic, shaping biogeochemical cycles and having a direct influence on phytoplankton growth. How variations in phenotype and sampling location, affect the phytoplankton microbiome is largely unknown. A high-resolution characterization of the bacterial community in cultures of the dinoflagellate Alexandrium was performed on strains isolated from different geographical locations and at varying anthropogenic impact levels. Microbiomes of Baltic Sea Alexandrium ostenfeldii isolates were dominated by Betaproteobacteria and were consistent over phenotypic and genotypic Alexandrium strain variation, resulting in identification of an A. ostenfeldii core microbiome. Comparisons with in situ bacterial communities showed that taxa found in this A. ostenfeldii core were specifically associated to dinoflagellate dynamics in the Baltic Sea. Microbiomes of Alexandrium tamarense and minutum, isolated from the Mediterranean Sea, differed from those of A. ostenfeldii in bacterial diversity and composition but displayed high consistency, and a core set of bacterial taxa was identified. This indicates that Alexandrium isolates with diverse phenotypes host predictable, species-specific, core microbiomes reflecting the abiotic conditions from which they were isolated. These findings enable in-depth studies of potential interactions occurring between Alexandrium and specific bacterial taxa.
  • Virkkala, Raimo; Leikola, Niko; Kujala, Heini; Kivinen, Sonja; Hurskainen, Pekka; Kuusela, Saija; Valkama, Jari; Heikkinen, Risto K. (Wiley, 2022)
    Ecological Applications
    The use of indicator species in forest conservation and management planning can facilitate enhanced preservation of biodiversity from the negative effects of forestry and other uses of land. However, this requires detailed and spatially comprehensive knowledge of the habitat preferences and distributions of selected focal indicator species. Unfortunately, due to limited resources for field surveys, only a small proportion of the occurrences of focal species is usually known. This shortcoming can be circumvented by using modeling techniques to predict the spatial distribution of suitable sites for the target species. Airborne laser scanning (ALS) and other remote sensing (RS) techniques have the potential to provide useful environmental data covering systematically large areas for these purposes. Here, we focused on six bird of prey and woodpecker species known to be good indicators of boreal forest biodiversity values. We used known nest sites of the six indicator species based on nestling ringing records. Thus, the most suitable nesting sites of these species provide important information for biodiversity-friendly forest management and conservation planning. We developed fine-grained, that is, 96 × 96 m grid cell resolution, predictive maps across the whole of Finland of the suitable nesting habitats based on ALS and other RS data and spatial information on the distribution of important forest stands for the six studied biodiversity indicator bird species based on nesting-habitat suitability modeling, that is, the MaxEnt model. Habitat preferences of the study species, as determined by MaxEnt, were in line with the previous knowledge of species-habitat relations. The proportion of suitable habitats of these species in protected areas (PAs) was considerable, but our analysis also revealed many potentially high-quality forest stands outside PAs. However, many of these sites are increasingly threatened by logging because of increased pressures for using forests for bioeconomy and forest industry based on National Forest Strategy. Predicting habitat suitability based on information on the nest sites of indicator species provides a new tool for systematic conservation planning over large areas in boreal forests in Europe, and a corresponding approach would also be feasible and recommendable elsewhere where similar data are available.
  • Forsblom, Louise; Engström-öst, Jonna; Lehtinen, Sirpa; Lips, Inga; Lindén, Andreas (2019)
    Journal of Plankton Research 41 (6), 925–938
    Abiotic variables subject to global change are known to affect plankton biomasses, and these effects can be species-specific. Here, we investigate the environmental drivers of annual biomass using plankton data from the Gulf of Finland in the northern Baltic Sea, spanning years 1993–2016. We estimated annual biomass time-series of 31 nanoplankton and microplankton species and genera from day-level data, accounting for the average phenology and wind. We found wind effects on day-level biomass in 16 taxa. We subsequently used state-space models to connect the annual biomass changes with potential environmental drivers (temperature, salinity, stratification, ice cover and inorganic nutrients), simultaneously accounting for temporal trends. We found clear environmental effects influencing the annual biomasses of Dinobryon faculiferum, Eutreptiella spp., Protoperidinium bipes, Pseudopedinella spp., Snowella spp. and Thalassiosira baltica and indicative effects in 10 additional taxa. These effects mostly concerned temperature, salinity or stratification. Together, these 16 taxa represent two-thirds of the summer biomass in the sampled community. The inter-annual variability observed in salinity and temperature is relatively low compared to scenarios of predicted change in these variables. Therefore, the potential impacts of the presented effects on plankton biomasses are considerable.
  • Heikkinen, Risto K.; Kartano, Linda; Leikola, Niko; Aalto, Juha; Aapala, Kaisu; Kuusela, Saija; Virkkala, Raimo (Elsevier, 2021)
    Global Ecology and Conservation 28, e01664
    The Habitats Directive of the European Union is a key legislative instrument in Europe, supporting the conservation of rare, threatened or endemic species. It aims at ensuring that the species listed in the Annexes of the Habitats Directive show a favourable conservation status, i.e., that they are able to maintain viable populations and that their natural range is sufficient and not decreasing currently, nor will in the future. However, climate change may hamper Habitats Directive species in achieving (or maintaining) a favourable conservation status, particularly when these impacts are amplified by adverse land use. Here, we studied Habitats Directive species in Finland for which ≥70% of the occurrences were recorded with the resolution of ≤100 m. The number of occurrence sites for the 52 species studied ranged from one site to 13,653 sites, summing up to 19,367 sites. For all these sites and their surroundings, we assessed the vulnerabilities caused by climate change and land use. The climate exposure of occurrence sites was measured based on the rapidity of climatic changes (i.e. climate velocity) in three climate variables (growing degree days, mean January air temperature, water balance) at each site. Risks caused by land use were assessed using two negative and four positive variables that respectively described the quantity of land cover and habitats that is either harmful (e.g. clear-cut forest and drained peatlands) or supportive (protected areas and suitable habitats) to species occurrences. To complement climate and land-use variables, three additional variables describing protection status of the sites and the number of occurrences of the same species in the landscape were examined. Comparison of the mean vulnerability values for each species showed that some of the species inhabit, on average, areas with high climate exposure. Moreover, in certain species climate change-induced vulnerabilities consistently coincide with negative land use. However, in many of the 52 species there was large variation in the vulnerability levels between individual occurrence sites, concerning both climate exposure and land-use variables. Considering the vulnerabilities due to climate change separately, 40–60% of the species occurrence sites are expected to face high exposure caused by rapid changes in summer or winter temperatures, which presents challenges in maintaining a favourable conservation status. Our results also revealed numerous species occurrences where high climate velocity coincided with a large amount of negative land use and low amount of suitable habitat, for which climate-wise conservation planning could be targeted.
  • Melero, Yolanda; Evans, Luke C.; Kuussaari, Mikko; Schmucki, Reto; Stefanescu, Constantí; Roy, David B.; Oliver, Tom H. (Springer Science and Business Media LLC, 2022)
    Communications Biology
    Climatic anomalies are increasing in intensity and frequency due to rapid rates of global change, leading to increased extinction risk for many species. The impacts of anomalies are likely to vary between species due to different degrees of sensitivity and extents of local adaptation. Here, we used long-term butterfly monitoring data of 143 species across six European bioclimatic regions to show how species’ population dynamics have responded to local or globally-calculated climatic anomalies, and how species attributes mediate these responses. Contrary to expectations, degree of apparent local adaptation, estimated from the relative population sensitivity to local versus global anomalies, showed no associations with species mobility or reproductive rate but did contain a strong phylogenetic signal. The existence of phylogenetically-patterned local adaptation to climate has important implications for forecasting species responses to current and future climatic conditions and for developing appropriate conservation practices.
  • Heino, Jani; Alahuhta, Janne; Fattorini, Simone (Wiley & Sons, 2019)
    Journal of Biogeography 2019; 46: 2548– 2557
    Aim Ecogeographical patterns have been widely studied in endothermic vertebrates, but relatively few studies have simultaneously examined patterns and causes of gradients in species richness, range size and body size in ectothermic insects. We examined patterns in species richness, mean range size and mean body size of ground beetle assemblages across the biogeographical provinces of Northern Europe, a region that was mostly covered by ice sheets during the latest Ice Age and that presents strong contemporary climatic gradients. Location Northern Europe. Methods We used literature information on the occurrence of ground beetles, and analysed patterns in species richness, mean range size and mean body size across the provinces using generalized linear models and boosted regression tree (BRT) analysis. Results We found a strongly decreasing gradient in species richness with increasing latitude, a strongly unimodal range size-latitude relationship, and a weak unimodal body size-latitude relationship in entire ground beetle assemblages. These gradients also varied among four major genera, suggesting that the overall patterns result from the nuances of smaller clades of ground beetles. The relative importance of contemporary environmental drivers also varied between species richness, mean range size and mean body size in BRT analysis. While species richness increased with mean annual temperature, mean range size showed an opposite relationship. Mean body size was most clearly associated with the precipitation of the driest month. Main Conclusions Our findings showed that the latitudinal species richness gradient was strong, and it was closely related to concomitant variation in temperature, whereas variations in mean range size and mean body size were more complex. These findings suggest that the causes for range size and body size variation in insects may be complex, requiring additional insights from studies conducted at local, regional and continental scales.
  • Vilmi, Annika; Tolonen, Kimmo T.; Karjalainen, Satu Maaria; Heino, Jani (Elsevier, 2019)
    Ecological Indicators, 99, 159-166
    We examined how niche position, niche breadth, biological traits and taxonomic relatedness affect interspecific variation in occupancy and abundance of two commonly-used biological indicator groups, i.e. diatoms and macroinvertebrates. We studied 291 diatom and 103 macroinvertebrate species that occupied the littoral zones of a large (305 km2) highly-connected freshwater system. We collated information on the biological traits and taxonomic relatedness of each species. Using principal coordinates analysis, we formed biological trait and taxonomic vectors describing distances between species and used the resulting vectors as predictor variables. As environmental data, we had site-specific physico-chemical variables, which were used in outlying mean index analyses to determine the niche position and niche breadth of each species. We used linear models to study if and how these two niche parameters and biological traits as well as taxonomic relatedness affected occupancy and abundance. We observed positive occupancy-abundance relationships for both diatoms and macroinvertebrates. We further found that, for both groups, occupancy was better explained by the predictor variables compared with abundance. We also observed that niche parameters, especially niche position, were the main determinants of variation in occupancy and abundance for both diatoms and macroinvertebrates. Local abundances of diatom and macroinvertebrate species were also, to a small degree, affected by biological traits or taxonomic relatedness. We further saw that the relationship between niche position and occupancy was negative, indicating that the more marginal the niche position, the rarer a species is. Our findings provide support for the use of diatoms and macroinvertebrates as ecological indicators as their occupancies and abundances were affected by niche parameters, which is not necessarily always clear in challenging study systems with high connectivity (i.e. high movement of material and species) among sites. These findings also suggest that indices using information on species’ occupancy, abundance and niche requirements are useful in environmental assessment.
  • Tuominen, Meeri (Helsingin yliopisto, 2021)
    Tämän maisterintutkielman tavoitteena on selvittää, kuinka paljon ja millaisia määräisyysvirheitä arvosanan M (magna cum laude approbatur) saaneet abiturientit tekevät ruotsin ylioppilaskokeeseen sisältyvässä kirjoitelmassa. Lisäksi vertaan pitkän ja keskipitkän oppimäärän kokeen tehneiden kirjoitelmista löytyviä virhemääriä ja -tyyppejä keskenään. Tutkimuksen aineisto koostuu yhteensä 60 Ylioppilastutkintolautakunnalta saamastani satunnaisesta kirjoitelmasta, joista 30 on pitkän oppimäärän (A-ruotsi) kokeesta ja 30 keskipitkän oppimäärän (B-ruotsi) kevään 2020 kokeesta. A-ruotsin kirjoitelmat (700–1100 merkkiä) ovat kaksi kertaa pidempiä kuin B-ruotsin kirjoitelmat (400–550 merkkiä). Analysoin kirjoitelmia Corderin (1974) luoman virheanalyysin avulla, lukuun ottamatta virheiden selittämistä tai arviointia. Etsin kirjoitelmista kaikki määräisyysvirheet, jonka jälkeen jaottelin ne pää- ja alakategorioihin. Jaottelin jokaisen määräisyysvirheitä sisältävän nominaalilausekkeen vain yhteen kategoriaan, vaikka lausekkeessa olisikin ollut useampi taivutusvirhe. Ruotsin kielen määräisyys ja artikkelien käyttö luo tunnetusti haasteita ruotsinoppijoille, sillä se eroaa huomattavasti esimerkiksi englannin ja suomen kielistä. Käyn läpi teoriaa ruotsin kielen määräisyydestä sekä esittelen aiempaa tutkimusta aiheeseen liittyen. Vaikka määräisyys koostuu sekä merkityksestä että muodosta, keskityn tässä tutkielmassa vain muotoon, sillä sitä painotetaan kouluopetuksessakin. Lisäksi selitän eron toisen ja vieraan kielen oppimisen välillä ja pohdin virheiden merkitystä kielenoppimisessa. Kielenoppimiseen liittyy Pienemannin (1998) prosessoitavuusteoria, jonka mukaan kielenoppiminen koostuu viidestä tasosta, joista edeltävä täytyy aina hallita siirtyäkseen seuraavalle tasolle. Määräisyys ja nominaalilausekkeiden taivutus kuuluvat tasoille 2 ja 3, jotka liittyvät sanojen taivutukseen sekä lausekkeiden sisäiseen kongruenssiin. Aineistosta löytyi yhteensä 160 määräisyysvirhettä, joista 107 on pitkän ruotsin ja 53 keskipitkän ruotsin kirjoitelmista. A-ruotsissa virheitä on keskimäärin neljä per kirjoitelma, B-ruotsissa kaksi. Pääkategorioita on neljä ja alakategorioita 15. Suurin pääkategoria on epämääräinen muoto määräisen muodon sijasta (58), toisiksi suurin määräinen muoto epämääräisen muodon sijasta (49), kolmanneksi suurin artikkelivirheet (27) ja pienin kongruenssivirheet (26). Yleisimpiä alakategorioita eli virhetyyppejä olivat epämääräinen muoto aiemmin mainituista asioista puhuttaessa, määräinen muoto epämääräistä muotoa vaativien attribuuttien jälkeen, artikkeliton muoto määräisen muodon sijasta sekä epämääräinen muoto prepositioilmauksissa. Aineistosta käy ilmi, että opiskelijat käyttävät useimmiten yksinkertaisimpia muotoja eli epämääräistä tai artikkelitonta muotoa. Muodon valitsemisen lisäksi vaikeuksia tuottaa sellaisten nominaalilausekkeiden muodostus, joihin sisältyy attribuutti. Tällaiset kongruenssivirheet olivat selvästi yleisempiä B-ruotsissa, mikä kertoo heikommasta nominaalilausekkeiden määräisyystaivutuksen osaamisesta. Määrällisesti A- ja B-ruotsin kirjoitelmissa oli saman verran virheitä suhteessa tekstien pituuteen, ainoastaan eri kategorioiden välillä oli eroja. Toisaalta A-ruotsin pidempiä ja haastavampia tekstejä kirjoittaessa tulee luonnollisesti enemmän virheitä kuin B-ruotsin lyhyissä teksteissä. Tulosten perusteella nämä opiskelijat ovat vielä prosessoitavuusteorian tasolla 2, sillä he eivät hallitse substantiivien määräisyysmuotojen käyttöä.
  • Suhonen, Jukka; Ilvonen, Jaakko J.; Korkeamäki, Esa; Nokkala, Christina; Salmela, Jukka (Wiley, 2022)
    Ecology and Evolution
    Understanding the risk of local extinction of a species is vital in conservation biology, especially now when anthropogenic disturbances and global warming are severely changing natural habitats. Local extinction risk depends on species traits, such as its geographical range size, fresh body mass, dispersal ability, length of flying period, life history variation, and how specialized it is regarding its breeding habitat. We used a phylogenetic approach because closely related species are not independent observations in the statistical tests. Our field data contained the local extinction risk of 31 odonate (dragonflies and damselflies) species from Central Finland. Species relatedness (i.e., phylogenetic signal) did not affect local extinction risk, length of flying period, nor the geographical range size of a species. However, we found that closely related species were similar in hind wing length, length of larval period, and habitat of larvae. Both phylogenetically corrected (PGLS) and uncorrected (GLM) analysis indicated that the geographical range size of species was negatively related to local extinction risk. Contrary to expectations, habitat specialist species did not have higher local extinction rates than habitat generalist species nor was it affected by the relatedness of species. As predicted, species’ long larval period increased, and long wings decreased the local extinction risk when evolutionary relatedness was controlled. Our results suggest that a relatively narrow geographical range size is an accurate estimate for a local extinction risk of an odonate species, but the species with long life history and large habitat niche width of adults increased local extinction risk. Because the results were so similar between PGLS and GLM methods, it seems that using a phylogenetic approach does not improve predicting local extinctions.
  • Vilmi, Annika; Karjalainen, Satu M.; Wang, Jianjun; Heino, Jani (2019)
    Journal of Biogeography 46 (7): 1419-1428
    Aim To discover how biological traits, ecological preferences and taxonomic relatedness are associated with occupancy and abundance of diatom species across lakes and streams. Location Finland. Taxon Diatoms. Methods We studied 288 diatom species from 492 stream sites and 230 diatom species from 290 lake sites. For each species, we calculated logit-transformed regional occupancy and log-transformed mean local abundance, and further determined biological traits, ecological preferences and taxonomic levels for each species. Boosted regression tree (BRT) analysis was used to reveal the linear and nonlinear associations of biological, ecological and taxonomic predictors with occupancy or abundance of lake and stream diatoms. Results There were strong and positive interspecific occupancy–abundance relationships across both lakes and streams. The BRT models explained more deviances in variation in occupancy and abundance and their relationship for lakes than streams. Biological traits, especially cell size, but also life-form and guild, were the strongest predictors of diatom occupancy and abundance in lakes and streams when controlling for ecological preferences and taxonomic relatedness. Main conclusions In general, biological traits were the strongest predictors of occupancy and abundance in both freshwater systems. Species with similar biological traits thus tended to show similar occupancies and abundances. As indicated by lower explained deviances, occupancy and abundance in streams seemed to be more complexly structured than in lakes, suggesting that these two freshwater system types differ in the formation of biodiversity patterns. This difference may be related to the differences in hydrological connectedness between lakes and streams. Understanding how variations in species’ occupancy and abundance are formed across various waterbodies is important for meaningful biodiversity conservation.
  • Purhonen, Jenna; Nerea, Abrego; Komonen, Atte; Huhtinen, Seppo; Kotiranta, Heikki; Læssøe, Thomas; Halme, Panu (Nature Publishing Group, 2021)
    Scientific Reports 11: 1
    The general negative impact of forestry on wood-inhabiting fungal diversity is well recognized, yet the effect of forest naturalness is poorly disentangled among different fungal groups inhabiting dead wood of different tree species. We studied the relationship between forest naturalness, log characteristics and diversity of different fungal morpho-groups inhabiting large decaying logs of similar quality in spruce dominated boreal forests. We sampled all non-lichenized fruitbodies from birch, spruce, pine and aspen in 12 semi-natural forest sites of varying level of naturalness. The overall fungal community composition was mostly determined by host tree species. However, when assessing the relevance of the environmental variables separately for each tree species, the most important variable varied, naturalness being the most important explanatory variable for fungi inhabiting pine and aspen. More strikingly, the overall species richness increased as the forest naturalness increased, both at the site and log levels. At the site scale, the pattern was mostly driven by the discoid and pyrenoid morpho-groups inhabiting pine, whereas at the log scale, it was driven by pileate and resupinate morpho-groups inhabiting spruce. Although our study demonstrates that formerly managed protected forests serve as effective conservation areas for most wood-inhabiting fungal groups, it also shows that conservation planning and management should account for group- or host tree -specific responses.