EcolChange-related conference – Biotic interactions and biodiversity patterns across scales

We are glad to announce the first Seminar of Doctoral School of Earth Sciences and Ecology on “Biotic interactions and biodiversity patterns accross scales.

The joint seminar with the Department of Botany (University of Tartu), Department of Ecology (Swedish University of Agricultural Sciences), Department of Ecology, Environment and Plant Sciences (Stockholm University) and Department of Agricultural Sciences (Helsinki University) will take place on May 4th, 2018 at University of Tartu.

 

The focus will be on doctoral students and young scientists to give them an opportunity to share their scientific work with an international audience and support the development of professional networks. The seminar will feature oral presentations (only invited contributions) and poster presentations.

The seminar is co-hosted by the Department of Botany of the University of Tartu, the Doctoral School of Earth Sciences and Ecology and the Centre of Excellence EcolChange.

All members of the Doctoral School of Earth Sciences and Ecology are welcome! The seminar has no participation fee, but registration is required.

Registration will close on April 30th (midnight)!

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EcolChange seminar – Inga Jüriado about lichen symbiosis

Seminar of Department of Botany and Centre of Excellence EcolChange

Speaker: Inga Jüriado is senior researcher in the team of lichenology at the Department of Botany.

Title of the talk: Relationships between mycobiont identity, photobiont specificity and ecological preferences in the genus Peltigera (Ascomycota) 

Time: Thursday, 12. April 2017 at 15.15

Place: Tartu, Lai 40-218 (Vaga auditorium)

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Lichen (and moss) biogeography… (pic from here)

Abstract:

Lichen symbioses always include at least one primary fungal symbiont, the mycobiont, and one or more photosynthetic partners, the photobionts (algae and/ or cyanobacteria). Although community scale patterns of photobiont diversity are most likely influenced by the environment, few molecular studies have so far addressed ecological segregation between closely related lichen photobionts. To find possible correlations between habitat specificity and photobiont selectivity photobiont diversity in Peltigera from different habitat types and growing on different substrates was compared. It is hypothesized that the cyanobacterial photobionts are not randomly distributed along the complex environmental gradient, but that their distributions correlate primarily with the species identities of host fungi and also with growth conditions.

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New publication – Shifts in tree functional composition amplify the response of forest biomass to climate

Text from emu.ee news

The scientist of Estonian University of Life Sciences involved in a study demonstrating that drought-induced changes in forest composition amplify effects of climate variability on forest carbon gain

Healthy forests play a key role in global ecosystems as they contain much of the terrestrial biodiversity and act as a net sink for atmospheric carbon. As climate change affects the forests, so do the forests affect climate change. The species composition of forests is changing due to climate change-induced shifts in rainfall and temperature and this causes more dramatic alterations in forest productivity than climate effects alone, according to a collaborative study of scientists of University of Florida, Estonian University of Life Sciences and Princeton University published in Nature.

The result of the means that forests facing global change are already starting to look different, but more importantly, it means the ability of those forests to soak up carbon is being altered as well, which could in turn bring about further climate change.

The study was based on forests of eastern United States, but the results can be generalized worldwide to natural forests and multi-species moderately managed forest where species composition is not controlled. “The changes we documented are easily blurred by other disturbances, which is probably why nobody had previously documented them. Without a long-term dataset with millions of trees, we would have been unable to detect these changes” said Prof. Ülo Niinemets, the scientist involved from Estonian University of Life Sciences.

The team based their findings on systematic forest inventories of trees in the eastern U.S. from the 1980s to the 2000s. The team looked specifically at forest biomass, tree species composition, and climate variability. The researchers found that decades of changes in water deficit have reduced forest biomass, leading to an increase of abundance of tree species that are more tolerant to drought but slower-growing. This shift results in significant changes in forest species composition with their accompanying ecological effects and, moreover, affects the capacity of forests to store carbon.

Forests are affected by other human activities such as farming or logging, and many are in a stage of ecological succession with lower biomass compared to mature forests. This history of disturbance made the researchers’ analysis challenging. To solve this, researchers compared forests on the basis of their age. “We compared forests in the 1980s of a given age (for example, an 80-year-old forest) to forests of the same age in the 2000s,” said Niinemets. “In areas where the climate got wetter, our analysis showed increases in biomass over the two decades, whereas in the areas that got drier, there were decreases in biomass. When we look at the eastern U.S. as a whole, there was an overall trend towards a drier climate from the 1980s to the 2000s, and therefore the overall effect of climate over the two decades was to reduce forest biomass.”

Drought-tolerant tree species tend to allocate more carbon to fine roots and less to their leaves and woody parts that would sequester more carbon. Niinemets  said that although they expected an increase in drought-tolerant tree abundance would prevent biomass losses triggered by water deficits, the opposite appears to be true. “Functional shifts amplified the effects of climate by making forest biomass more responsive to drying or wetting,” he said. “In hindsight, this makes sense, because drought-tolerant species tend to be slow growing. So, if drought causes a shift towards more drought-tolerant species, biomass will decline compared to forests dominated by fast-growing, drought-intolerant species.”

Overall, the study shows that forest biomass and tree species composition and their combined impact on carbon storage are affected by climatic variability on a sensitive and short timeline — just a few decades. “We are confident that our findings on climate-driven changes in species composition and resulting biological controls on forest productivity will stimulate further research into relationships between species composition, ecosystem function, and climate variability.”

Citation: Zhang, T., Niinemets, Ü., Sheffield, J., & Lichstein, J. W. (2018). Shifts in tree functional composition amplify the response of forest biomass to climate. Nature, DOI: 10.1038/nature26152 (link to full text)

Abstract:

Forests have a key role in global ecosystems, hosting much of the world’s terrestrial biodiversity and acting as a net sink for atmospheric carbon. These and other ecosystem services that are provided by forests may be sensitive to climate change as well as climate variability on shorter time scales (for example, annual to decadal). Previous studies have documented responses of forest ecosystems to climate change and climate variability, including drought-induced increases in tree mortality rates. However, relationships between forest biomass, tree species composition and climate variability have not been quantified across a large region using systematically sampled data. Here we use systematic forest inventories from the 1980s and 2000s across the eastern USA to show that forest biomass responds to decadal-scale changes in water deficit, and that this biomass response is amplified by concurrent changes in community-mean drought tolerance, a functionally important aspect of tree species composition. The amplification of the direct effects of water stress on biomass occurs because water stress tends to induce a shift in tree species composition towards species that are more tolerant to drought but are slower growing. These results demonstrate concurrent changes in forest species composition and biomass carbon storage across a large, systematically sampled region, and highlight the potential for climate-induced changes in forest ecosystems across the world, resulting from both direct effects of climate on forest biomass and indirect effects mediated by shifts in species composition.

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New publication – Glandular trichomes as a barrier against atmospheric oxidative stress: Relationships with ozone uptake, leaf damage, and emission of LOX products across a diverse set of species

Text from Research in Estonia page (translated from this Novaator article)

Study led by scientists from the Estonian University of Life Sciences indicate that many crops with hairier leaves tolerate ground-level ozone better. The relative content of ground-level ozone in the air has significantly increased since the beginning of the 20th century. It seems that this trend will continue in the future. However, this gas is an environmental poison and harmful to living organisms. Compared to the beginning of the current century, large-scale ozone damage to forest trees as well as on crops has been recorded all over the world.

In a recently-published paper, an international working group, which was led by Estonian plant physiologist from EMÜ, looked at how the gland-tipped hairs of plants protect against the harmful effects of ozone. Plant epidermis has about ten different types of these hairs. Their density also varies between species with some species lacking these hairs altogether. So far, the gland-tipped hairs were primarily associated with a plant’s ability to fight against herbivory.

This time, the scientists limited their focus to agriculturally important plants, such as pumpkins, cucumbers, lavender, rosemary, etc. The research group found that the gland-tipped hairs excrete compounds which have an ozone-neutralising effect. Plants with hairier leaves were significantly more resistant to a high concentration of ozone. Their leaves developed the brown spots marking ozone damage later than less-hairy species.

This paper is significant because, for the first time in history, the  gland-tipped hairs have assumed an important function as neutralisers of ozone.

 

Citation: Li, S., Tosens, T., Harley, P. C., Jiang, Y., Kanagendran, A., Grosberg, M., Jaamets, K. & Niinemets, Ü. (2018). Glandular trichomes as a barrier against atmospheric oxidative stress: relationships with ozone uptake, leaf damage and emission of LOX products across a diverse set of species. Plant, cell & environment, doi.org/10.1111/pce.13128 (link to full text).

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Gravitational life-history effects on male trichomes. So far probably not tested in plants… (pic from here)

Abstract:

There is a spectacular variability in trichome types and densities and trichome metabolites across species, but the functional implications of this variability in protecting from atmospheric oxidative stresses remain poorly understood. The aim of this study was to evaluate the possible protective role of glandular and non‐glandular trichomes against ozone stress. We investigated the interspecific variation in types and density of trichomes and how these traits were associated with elevated ozone impacts on visible leaf damage, net assimilation rate, stomatal conductance, chlorophyll fluorescence, and emissions of lipoxygenase pathway products in 24 species with widely varying trichome characteristics and taxonomy. Both peltate and capitate glandular trichomes played a critical role in reducing leaf ozone uptake, but no impact of non‐glandular trichomes was observed. Across species, the visible ozone damage varied 10.1‐fold, reduction in net assimilation rate 3.3‐fold, and release of lipoxygenase compounds 14.4‐fold, and species with lower glandular trichome density were more sensitive to ozone stress and more vulnerable to ozone damage compared to species with high glandular trichome density. These results demonstrate that leaf surface glandular trichomes constitute a major factor in reducing ozone toxicity and function as a chemical barrier that neutralizes the ozone before it enters the leaf.

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EcolChange seminar – Ülo Mander and Jaan Pärn about the global laughing gas balances of organic soils

Seminar of Department of Geography and Centre of Excellence EcolChange

Speakers: Ülo Mander is the professor of Physical Geography and Landscape Ecology in the University of Tartu, Estonia. Jaan Pärn is is postdoctoral research fellow at Keele University and the University of Birmingham, United Kingdom

Topic of the talk: Presentation of brand-new Nature Communications and Scientific Reports papers (link 1 and link 2, respectively) on the global laughing gas balances of organic soils, summarizing results of the 7-year long study mostly conducted by researchers and PhD students of the Department of Geography, University of Tartu.

Time: Tuesday, 20. March 2017 at 16.15

Place: Coffee room of the Department of Geography, University of Tartu (room 334, Vanemuise 46), Tartu.

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This blog post was compiled in an airport, therefore the illustration (pic from here)

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EcolChange seminar – Kadri Koorem about biotic interactions in range-expanding plant species

Seminar of Department of Botany and Centre of Excellence EcolChange

Speaker: Kadri Koorem is postdoctoral researcher of Tartu University at NIOO-KNAW, The Netherlands.

Title of the talk: Biotic interactions of range-expanding plant species

Time: Thursday, 22. March 2017 at 15.15

Place: Tartu, Lai 40-218 (Vaga auditorium)

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Abstract:

Current climate change has enabled many organisms to expand their range to higher altitudes and latitudes. While the movement of organisms like plants is relatively well recorded, much less is known how such process influences the interactions between plants and their biotic environment. I will show what we’ve learned about the interactions between range expanding plants, native plants, soil organisms and insects.

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New publication – Homogenization and impoverishment of taxonomic and functional diversity of ants in Eucalyptus plantations

Text Carlos P. Carmona

Eucalyptus species are among the most most controversial and frequently used species in forests plantations worldwide. These plantations occupy a huge surface in many countries, with almost 8 millions ha in Brazil alone, where they are generally located in heterogeneous landscapes which also include native forest patches and a variety of other non-forest land uses. Eucalyptus plantations generally receive a high input of fertilizers and are very water demanding. On top of that, forestry practices in these plantations have profound impacts on soil structure. On the other hand, when compared to non-forest uses, these plantations can harbor some native species typical from forests and increase landscape connectivity, facilitating the movements of these species. Therefore, it is unclear what is their impact in diversity, and some studies have shown that there are not more species poor than primary forests.

However, the concept of biological diversity goes beyond the taxonomic aspect. In this sense, it is increasingly clear that the diversity and identity of the traits of organisms is a better indicator of the functioning of ecosystems than species richness per se. Some taxonomic groups are particularly interesting for evaluating the impact of human activities. Ants are one of these groups; ants are involved in a great number of ecological processes, ranging from soil cycling to seed dispersion and decomposition of organic matter, and are also very good indicators of anthropic disturbances. Consequently, studying the functional diversity of ants in Eucalyptus plantations could give us a better idea of the ecological impacts of this land use.

In this study, conducted at the Alto Tietê and Itatinga River basins, in São Paulo, Brazil, we compared the functional trait structure of ant communities in four types of forests: young (7 years old) Eucalyptus plantations currently being managed for wood and cellulose production; old (28 years) Eucalyptus plantations also under intensive ongoing management; abandoned Eucalyptus plantations; and original native rain forest. We sampled ant communities from these forests, capturing individuals of 78 different species of ants, and measured several morphological traits in them (traits like distance between the eyes, head size, eye length, or mandible size, which were related to different processes, such as foraging, thermal and drought resistance, or behavior). In addition to their taxonomic diversity, we used these traits and the species composition of each forest to estimate the functional structure of our ant communities using a novel framework that allows to consider intraspecific variability in trait values (thus acknowledging that not all the individuals of the same species have the same trait values).

Interestingly, whereas the number of species present in managed Eucalyptus plantations was almost half of that found in native forests, abandoned Eucalyptus plantations had as many species as native forests. However, we found that ant communities in Eucalyptus plantations, regardless of their management status, had much lower functional diversity than native forests. This effectively means that Eucalyptus plantations have a great impact on diversity and ecosystem functioning, an impact that does not disappear even after long a long period of abandonment. Moreover, the patches of native forests were also much more different between them than the patches of Eucalyptus forests, which implies that these plantations have a negative impact on diversity at the landscape scale. Altogether, our results imply that many of the species that colonized the abandoned plantations were functionally very similar between them, probably because they share characteristics that allow them to survive in this kind of environment. Our findings support the idea that Eucalyptus plantations can severely affect the taxonomic and functional diversities of ant communities, and that these impacts have long-term effects, even in unmanaged plantations. However, we would not have been able to detect these impacts by merely looking at the taxonomical facet of diversity, which calls for a more comprehensive evaluation of the impacts of human activities on biological communities. On the bright side, and communities from long term abandoned Eucalyptus plantations showed a tendency to converge with the communities from the original forests, which suggests that the implementation of restoration strategies, such as passive restoration between stands of tree plantation, may mitigate some impacts of this land use on ant communities, and on the ecological processes in which these insects are essential.

 

Citation: Martello, F., de Bello, F., de Castro Morini, M. S., Silva, R. R., de Souza-Campana, D. R., Ribeiro, M. C., & Carmona, C. P. (2018). Homogenization and impoverishment of taxonomic and functional diversity of ants in Eucalyptus plantations. Scientific reports, 8(1), 3266. (link to full text)

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Mean and standard deviation of taxonomic (A) and functional (BD) α diversity indices of ant communities located in native rain forest, 28-year-old unmanaged Eucalyptus plantations, seven-year-old commercial Eucalyptus plantations and 28-year-old Eucalyptus plantations. Different letters associated with the environments represent significant differences in the means assessed by Tukey’s Post-hoc analysis. (Graph from the paper)

Abstract:

Despite its negative impacts on the environment and biodiversity, tree plantations can contribute to biodiversity conservation in fragmented landscapes, as they harbor many native species. In this study, we investigated the impact of Eucalyptus plantations on the taxonomic and functional diversity of ant communities, comparing ant communities sampled in managed and unmanaged (abandoned for 28 years) Eucalyptus plantations, and native Atlantic rain forests. Eucalyptus plantations, both managed and unmanaged, reduced the functional diversity and increased the similarity between ant communities leading to functional homogenization. While communities in managed plantations had the lowest values of both taxonomic and functional ant diversities, ant communities from unmanaged plantations had similar values of species richness, functional redundancy and Rao’s Q compared to ant communities from forest patches (although functional richness was lower). In addition, communities in unmanaged Eucalyptus plantations were taxonomically and functionally more similar to communities located in managed plantations, indicating that Eucalyptus plantations have a severe long-term impact on ant communities. These results indicate that natural regeneration may mitigate the impact of Eucalyptus management, particularly regarding the functional structure of the community (α diversity), although it does not attenuate the effects of long term homogenization in community composition (β diversity).

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EcolChange seminar – Maarika Mänd about pollinating strawberries

Seminar of Department of Botany and Centre of Excellence EcolChange

Speaker: Prof. Marika Mänd is head of the Chair of Plant Health at the Estonian University of Life Sciences.

Title of the talk: Pollinators in plant protection: hazards and utility possibilities

Time: Thursday, 15. March 2017 at 15.15

Place: Tartu, Lai 40-218 (Vaga auditorium)

Abstract:

Strawberry is an extremely important crop in Europe, with a very good marketing potential. However, it suffers heavily from the grey mould disease, against which organic growers have no protection methods. Microorganisms for biological control are available, but either are not practical or too expensive to use for reliable plant protection. The key question is how to deliver the crop protectant to the flowers at the right time, and in quantities large enough. One solution is to use bees who transport the plant protection product to flowers. This technique requires knowledge on several interactions between the vector, the target crop and the pest organism.

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EcolChange seminar – Aveliina Helm about everyone’s nature conservation

Seminar of Department of Botany and Centre of Excellence EcolChange

Speaker: Aveliina Helm is senior researcher at macroecology workgroup of the Department of Botany.

Title of the talk: Everyone’s nature conservation – what it is and why it is needed?

Time: Thursday, 01. March 2017 at 15.15

Place: Tartu, Lai 40-218 (Vaga auditorium)

Abstract:

Actions for protecting biodiversity need to be taken on the local scale, thus we need broad involvement of general public in conservation efforts. Everyone’s nature conservation is a concept that emphasizes the role of voluntary conservation efforts of individuals and small communities in improving the condition of habitats and species. I will introduce the conservation actions within everyone’s nature conservation and hope to have everybody’s input to the discussion about the possibilities of incentivizing general public in conservation actions.

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EcolChange seminar – Üllas Erlich about economic evaluation of nature

Seminar of Department of Botany and Centre of Excellence EcolChange

Speaker: Üllas Ehrlich is professor of environmental economics at the School of Business and Governance of Tallinn University of Technology.

Title of the talk: Economic evaluation of non-market values of nature

Time: Thursday, 22. February 2017 at 14.15

Place: Tartu, Lai 40-218 (Vaga auditorium)

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The ultimate market bubble (pic from here)

Abstract:

According to welfare economics, individuals are trying to use available goods and services in the manner and proportions that would maximize their welfare. Only some products and services have monetary equivalent or price and one can buy them on the market. Such goods are called market goods and their value or ability to raise an individual’s welfare is proportional to the market price. However, an individual’s welfare depends not only on market goods but a significant role in welfare is played also by such goods and services that are not traded in the market and therefore have no monetary equivalent in the market. Such goods are called non-market goods. Examples of non-market goods might be clean air, scenery, knowledge about biological species, for example, pandas (Ailuropoda melanoleuca). In economics, every good and service that increases an individual’s welfare has economic value. A problem is how to attribute value to non-market goods in order to make them comparable to other goods traded in the market in decision-making process. This is especially important in the case of a competitive or exclusive way of using a resource. The speaker discusses options and gives examples of the economic evaluation of non-market natural resources.

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