Skip header and navigation

5 records – page 1 of 1.

Accounting for environmental variation in co-occurrence modelling reveals the importance of positive interactions in root-associated fungal communities.

https://arctichealth.org/en/permalink/ahliterature305463
Source
Mol Ecol. 2020 07; 29(14):2736-2746
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
07-2020
Author
Nerea Abrego
Tomas Roslin
Tea Huotari
Ayco J M Tack
Björn D Lindahl
Gleb Tikhonov
Panu Somervuo
Niels Martin Schmidt
Otso Ovaskainen
Author Affiliation
Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland.
Source
Mol Ecol. 2020 07; 29(14):2736-2746
Date
07-2020
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Abstract
Understanding the role of interspecific interactions in shaping ecological communities is one of the central goals in community ecology. In fungal communities, measuring interspecific interactions directly is challenging because these communities are composed of large numbers of species, many of which are unculturable. An indirect way of assessing the role of interspecific interactions in determining community structure is to identify the species co-occurrences that are not constrained by environmental conditions. In this study, we investigated co-occurrences among root-associated fungi, asking whether fungi co-occur more or less strongly than expected based on the environmental conditions and the host plant species examined. We generated molecular data on root-associated fungi of five plant species evenly sampled along an elevational gradient at a high arctic site. We analysed the data using a joint species distribution modelling approach that allowed us to identify those co-occurrences that could be explained by the environmental conditions and the host plant species, as well as those co-occurrences that remained unexplained and thus more probably reflect interactive associations. Our results indicate that not only negative but also positive interactions play an important role in shaping microbial communities in arctic plant roots. In particular, we found that mycorrhizal fungi are especially prone to positively co-occur with other fungal species. Our results bring new understanding to the structure of arctic interaction networks by suggesting that interactions among root-associated fungi are predominantly positive.
PubMed ID
32562300 View in PubMed
Less detail

Beyond metacommunity paradigms: habitat configuration, life history, and movement shape an herbivore community on oak.

https://arctichealth.org/en/permalink/ahliterature271095
Source
Ecology. 2015 Dec;96(12):3175-85
Publication Type
Article
Date
Dec-2015
Author
Chaozhi Zheng
Otso Ovaskainen
Tomas Roslin
Ayco J M Tack
Source
Ecology. 2015 Dec;96(12):3175-85
Date
Dec-2015
Language
English
Publication Type
Article
Keywords
Animals
Computer simulation
Ecosystem
Finland
Herbivory - physiology
Insects - classification - physiology
Models, Biological
Population Dynamics
Quercus
Abstract
Many empirical studies of metacommunities have focused on the classification of observational patterns into four contrasting paradigms characterized by different levels of movement and habitat heterogeneity. However, deeper insight into the underlying local and regional processes may be derived from a combination of long-term observational data and experimental studies. With the aim of exploring forces structuring the insect metacommunity on oak, we fit a hierarchical Bayesian state-space model to data from observations and experiments. The fitted model reveals large variation in species-specific dispersal abilities and basic reproduction numbers, R0. The residuals from the model show only weak correlations among species, suggesting a lack of strong interspecific interactions. Simulations with model-derived parameter estimates indicate that habitat configuration and species attributes both contribute substantially to structuring insect communities. Overall, our findings demonstrate that community-level variation in movement and life history are key drivers of metacommunity dynamics.
PubMed ID
26909424 View in PubMed
Less detail

Ecological and evolutionary implications of spatial heterogeneity during the off-season for a wild plant pathogen.

https://arctichealth.org/en/permalink/ahliterature257833
Source
New Phytol. 2014 Apr;202(1):297-308
Publication Type
Article
Date
Apr-2014
Author
Ayco J M Tack
Anna-Liisa Laine
Author Affiliation
Metapopulation Research Group, Department of Biosciences, University of Helsinki, PO Box 65 (Viikinkaari 1), FI-00014, Helsinki, Finland.
Source
New Phytol. 2014 Apr;202(1):297-308
Date
Apr-2014
Language
English
Publication Type
Article
Keywords
Ascomycota - physiology
Biological Evolution
Ecosystem
Extinction, Biological
Finland
Host-Pathogen Interactions - physiology
Plant Diseases - microbiology
Plantago - microbiology
Seasons
Time Factors
Abstract
While recent studies have elucidated many of the factors driving parasite dynamics during the growing season, the ecological and evolutionary dynamics during the off-season (i.e. the period between growing seasons) remain largely unexplored. We combined large-scale surveys and detailed experiments to investigate the overwintering success of the specialist plant pathogen Podosphaera plantaginis on its patchily distributed host plant Plantago lanceolata in the Åland Islands. Twelve years of epidemiological data establish the off-season as a crucial stage in pathogen metapopulation dynamics, with c. 40% of the populations going extinct during the off-season. At the end of the growing season, we observed environmentally mediated variation in the production of resting structures, with major consequences for spring infection at spatial scales ranging from single individuals to populations within a metapopulation. Reciprocal transplant experiments further demonstrated that pathogen population of origin and overwintering site jointly shaped infection intensity in spring, with a weak signal of parasite adaptation to the local off-season environment. We conclude that environmentally mediated changes in the distribution and evolution of parasites during the off-season are crucial for our understanding of host-parasite dynamics, with applied implications for combating parasites and diseases in agriculture, wildlife and human disease systems.
PubMed ID
24372358 View in PubMed
Less detail

Higher host plant specialization of root-associated endophytes than mycorrhizal fungi along an arctic elevational gradient.

https://arctichealth.org/en/permalink/ahliterature304907
Source
Ecol Evol. 2020 Aug; 10(16):8989-9002
Publication Type
Journal Article
Date
Aug-2020
Author
Nerea Abrego
Tea Huotari
Ayco J M Tack
Björn D Lindahl
Gleb Tikhonov
Panu Somervuo
Niels Martin Schmidt
Otso Ovaskainen
Tomas Roslin
Author Affiliation
Department of Agricultural Sciences University of Helsinki Helsinki Finland.
Source
Ecol Evol. 2020 Aug; 10(16):8989-9002
Date
Aug-2020
Language
English
Publication Type
Journal Article
Abstract
How community-level specialization differs among groups of organisms, and changes along environmental gradients, is fundamental to understanding the mechanisms influencing ecological communities. In this paper, we investigate the specialization of root-associated fungi for plant species, asking whether the level of specialization varies with elevation. For this, we applied DNA barcoding based on the ITS region to root samples of five plant species equivalently sampled along an elevational gradient at a high arctic site. To assess whether the level of specialization changed with elevation and whether the observed patterns varied between mycorrhizal and endophytic fungi, we applied a joint species distribution modeling approach. Our results show that host plant specialization is not environmentally constrained in arctic root-associated fungal communities, since there was no evidence for changing specialization with elevation, even if the composition of root-associated fungal communities changed substantially. However, the level of specialization for particular plant species differed among fungal groups, root-associated endophytic fungal communities being highly specialized on particular host species, and mycorrhizal fungi showing almost no signs of specialization. Our results suggest that plant identity affects associated mycorrhizal and endophytic fungi differently, highlighting the need of considering both endophytic and mycorrhizal fungi when studying specialization in root-associated fungal communities.
PubMed ID
32884673 View in PubMed
Less detail

Increasing frequency of low summer precipitation synchronizes dynamics and compromises metapopulation stability in the Glanville fritillary butterfly.

https://arctichealth.org/en/permalink/ahliterature271563
Source
Proc Biol Sci. 2015 May 7;282(1806):20150173
Publication Type
Article
Date
May-7-2015
Author
Ayco J M Tack
Tommi Mononen
Ilkka Hanski
Source
Proc Biol Sci. 2015 May 7;282(1806):20150173
Date
May-7-2015
Language
English
Publication Type
Article
Keywords
Animals
Butterflies - growth & development - physiology
Climate change
Finland
Larva - growth & development - physiology
Population Dynamics
Rain
Seasons
Abstract
Climate change is known to shift species' geographical ranges, phenologies and abundances, but less is known about other population dynamic consequences. Here, we analyse spatio-temporal dynamics of the Glanville fritillary butterfly (Melitaea cinxia) in a network of 4000 dry meadows during 21 years. The results demonstrate two strong, related patterns: the amplitude of year-to-year fluctuations in the size of the metapopulation as a whole has increased, though there is no long-term trend in average abundance; and there is a highly significant increase in the level of spatial synchrony in population dynamics. The increased synchrony cannot be explained by increasing within-year spatial correlation in precipitation, the key environmental driver of population change, or in per capita growth rate. On the other hand, the frequency of drought during a critical life-history stage (early larval instars) has increased over the years, which is sufficient to explain the increasing amplitude and the expanding spatial synchrony in metapopulation dynamics. Increased spatial synchrony has the general effect of reducing long-term metapopulation viability even if there is no change in average metapopulation size. This study demonstrates how temporal changes in weather conditions can lead to striking changes in spatio-temporal population dynamics.
Notes
Cites: Nature. 2003 Jan 2;421(6918):37-4212511946
Cites: Am Nat. 2004 Sep;164(3):364-7715478091
Cites: Science. 2011 Aug 19;333(6045):1024-621852500
Cites: Proc Natl Acad Sci U S A. 2010 Aug 24;107(34):15135-920696913
Cites: Nature. 2002 Nov 14;420(6912):168-7112432390
Cites: Science. 2000 Sep 22;289(5487):2068-7411000103
Cites: Proc Natl Acad Sci U S A. 2011 Aug 30;108(35):14397-40421788506
Cites: Oecologia. 2011 Oct;167(2):559-7121590332
Cites: Physiol Biochem Zool. 2011 Nov-Dec;84(6):543-5222030847
Cites: J Epidemiol Community Health. 2012 Sep;66(9):759-6022766781
Cites: Ecol Lett. 2013 Jun;16(6):799-80623438320
Cites: Ecol Lett. 2010 Apr;13(4):473-8420148927
Cites: Proc Natl Acad Sci U S A. 2009 Jul 7;106(27):11172-619541649
Cites: Oecologia. 2007 Sep;153(3):569-7817566782
Cites: Science. 2006 Jul 14;313(5784):224-616840700
Cites: Science. 2006 Jun 9;312(5779):1477-816763134
Cites: Annu Rev Physiol. 2005;67:177-20115709956
Cites: Science. 2005 Jun 24;308(5730):1912-515890845
Cites: Proc Natl Acad Sci U S A. 2014 Jul 22;111(29):10636-4124979776
Cites: J Anim Ecol. 2013 May;82(3):529-3923347450
Cites: Proc Biol Sci. 2014 Mar 22;281(1779):2013261224478296
Cites: Glob Chang Biol. 2013 Aug;19(8):2373-8023630036
PubMed ID
25854888 View in PubMed
Less detail