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1. The global EPTO database:worldwide occurrences of aquatic insects

Author

Grigoropoulou, A. (Afroditi), Ab Hamid, S. (Suhaila), Acosta, R. (Raúl), Akindele, E. O. (Emmanuel Olusegun), Al-Shami, S. A. (Salman A.), Altermatt, F. (Florian), Amatulli, G. (Giuseppe), Angeler, D. G. (David G.), Arimoro, F. O. (Francis O.), Aroviita, J. (Jukka), Astorga-Roine, A. (Anna), Bastos, R. C. (Rafael Costa), Bonada, N. (Núria), Boukas, N. (Nikos), Brand, C. (Cecilia), Bremerich, V. (Vanessa), Bush, A. (Alex), Cai, Q. (Qinghua), Callisto, M. (Marcos), Chen, K. (Kai), Cruz, P. V. (Paulo Vilela), Dangles, O. (Olivier), Death, R. (Russell), Deng, X. (Xiling), Domínguez, E. (Eduardo), Dudgeon, D. (David), Eriksen, T. E. (Tor Erik), Faria, A. P. (Ana Paula J.), Feio, M. J. (Maria João), Fernández-Aláez, C. (Camino), Floury, M. (Mathieu), García-Criado, F. (Francisco), García-Girón, J. (Jorge), Graf, W. (Wolfram), Grönroos, M. (Mira), Haase, P. (Peter), Hamada, N. (Neusa), He, F. (Fengzhi), Heino, J. (Jani), Holzenthal, R. (Ralph), Huttunen, K.-L. (Kaisa-Leena), Jacobsen, D. (Dean), Jähnig, S. C. (Sonja C.), Jetz, W. (Walter), Johnson, R. K. (Richard K.), Juen, L. (Leandro), Kalkman, V. (Vincent), Kati, V. (Vassiliki), Keke, U. N. (Unique N.), Koroiva, R. (Ricardo), Kuemmerlen, M. (Mathias), Langhans, S. D. (Simone Daniela), Ligeiro, R. (Raphael), Van Looy, K. (Kris), Maasri, A. (Alain), Marchant, R. (Richard), Garcia Marquez, J. R. (Jaime Ricardo), Martins, R. T. (Renato T.), Melo, A. S. (Adriano S.), Metzeling, L. (Leon), Miserendino, M. L. (Maria Laura), Moe, S. J. (S. Jannicke), Molineri, C. (Carlos), Muotka, T. (Timo), Mustonen, K.-R. (Kaisa-Riikka), Mykrä, H. (Heikki), Cavalcante Do Nascimento, J. M. (Jeane Marcelle), Valente-Neto, F. (Francisco), Neu, P. J. (Peter J.), Nieto, C. (Carolina), Pauls, S. U. (Steffen U.), Paulson, D. R. (Dennis R.), Rios-Touma, B. (Blanca), Rodrigues, M. E. (Marciel Elio), de Oliveira Roque, F. (Fabio), Salazar Salina, J. C. (Juan Carlos), Schmera, D. (Dénes), Schmidt-Kloiber, A. (Astrid), Shah, D. N. (Deep Narayan), Simaika, J. P. (John P.), Siqueira, T. (Tadeu), Tachamo-Shah, R. D. (Ram Devi), Theischinger, G. (Günther), Thompson, R. (Ross), Tonkin, J. D. (Jonathan D.), Torres-Cambas, Y. (Yusdiel), Townsend, C. (Colin), Turak, E. (Eren), Twardochleb, L. (Laura), Wang, B. (Beixin), Yanygina, L. (Liubov), Zamora-Muñoz, C. (Carmen), Domisch, S. (Sami), Grigoropoulou, A. (Afroditi), Ab Hamid, S. (Suhaila), Acosta, R. (Raúl), Akindele, E. O. (Emmanuel Olusegun), Al-Shami, S. A. (Salman A.), Altermatt, F. (Florian), Amatulli, G. (Giuseppe), Angeler, D. G. (David G.), Arimoro, F. O. (Francis O.), Aroviita, J. (Jukka), Astorga-Roine, A. (Anna), Bastos, R. C. (Rafael Costa), Bonada, N. (Núria), Boukas, N. (Nikos), Brand, C. (Cecilia), Bremerich, V. (Vanessa), Bush, A. (Alex), Cai, Q. (Qinghua), Callisto, M. (Marcos), Chen, K. (Kai), Cruz, P. V. (Paulo Vilela), Dangles, O. (Olivier), Death, R. (Russell), Deng, X. (Xiling), Domínguez, E. (Eduardo), Dudgeon, D. (David), Eriksen, T. E. (Tor Erik), Faria, A. P. (Ana Paula J.), Feio, M. J. (Maria João), Fernández-Aláez, C. (Camino), Floury, M. (Mathieu), García-Criado, F. (Francisco), García-Girón, J. (Jorge), Graf, W. (Wolfram), Grönroos, M. (Mira), Haase, P. (Peter), Hamada, N. (Neusa), He, F. (Fengzhi), Heino, J. (Jani), Holzenthal, R. (Ralph), Huttunen, K.-L. (Kaisa-Leena), Jacobsen, D. (Dean), Jähnig, S. C. (Sonja C.), Jetz, W. (Walter), Johnson, R. K. (Richard K.), Juen, L. (Leandro), Kalkman, V. (Vincent), Kati, V. (Vassiliki), Keke, U. N. (Unique N.), Koroiva, R. (Ricardo), Kuemmerlen, M. (Mathias), Langhans, S. D. (Simone Daniela), Ligeiro, R. (Raphael), Van Looy, K. (Kris), Maasri, A. (Alain), Marchant, R. (Richard), Garcia Marquez, J. R. (Jaime Ricardo), Martins, R. T. (Renato T.), Melo, A. S. (Adriano S.), Metzeling, L. (Leon), Miserendino, M. L. (Maria Laura), Moe, S. J. (S. Jannicke), Molineri, C. (Carlos), Muotka, T. (Timo), Mustonen, K.-R. (Kaisa-Riikka), Mykrä, H. (Heikki), Cavalcante Do Nascimento, J. M. (Jeane Marcelle), Valente-Neto, F. (Francisco), Neu, P. J. (Peter J.), Nieto, C. (Carolina), Pauls, S. U. (Steffen U.), Paulson, D. R. (Dennis R.), Rios-Touma, B. (Blanca), Rodrigues, M. E. (Marciel Elio), de Oliveira Roque, F. (Fabio), Salazar Salina, J. C. (Juan Carlos), Schmera, D. (Dénes), Schmidt-Kloiber, A. (Astrid), Shah, D. N. (Deep Narayan), Simaika, J. P. (John P.), Siqueira, T. (Tadeu), Tachamo-Shah, R. D. (Ram Devi), Theischinger, G. (Günther), Thompson, R. (Ross), Tonkin, J. D. (Jonathan D.), Torres-Cambas, Y. (Yusdiel), Townsend, C. (Colin), Turak, E. (Eren), Twardochleb, L. (Laura), Wang, B. (Beixin), Yanygina, L. (Liubov), Zamora-Muñoz, C. (Carmen), and Domisch, S. (Sami)

Abstract

Motivation: Aquatic insects comprise 64% of freshwater animal diversity and are widely used as bioindicators to assess water quality impairment and freshwater ecosystem health, as well as to test ecological hypotheses. Despite their importance, a comprehensive, global database of aquatic insect occurrences for mapping freshwater biodiversity in macroecological studies and applied freshwater research is missing. We aim to fill this gap and present the Global EPTO Database, which includes worldwide geo-referenced aquatic insect occurrence records for four major taxa groups: Ephemeroptera, Plecoptera, Trichoptera and Odonata (EPTO). Main type of variables contained: A total of 8,368,467 occurrence records globally, of which 8,319,689 (99%) are publicly available. The records are attributed to the corresponding drainage basin and sub-catchment based on the Hydrography90m dataset and are accompanied by the elevation value, the freshwater ecoregion and the protection status of their location. Spatial location and grain: The database covers the global extent, with 86% of the observation records having coordinates with at least four decimal digits (11.1 m precision at the equator) in the World Geodetic System 1984 (WGS84) coordinate reference system. Time period and grain: Sampling years span from 1951 to 2021. Ninety-nine percent of the records have information on the year of the observation, 95% on the year and month, while 94% have a complete date. In the case of seven sub-datasets, exact dates can be retrieved upon communication with the data contributors. Major taxa and level of measurement: Ephemeroptera, Plecoptera, Trichoptera and Odonata, standardized at the genus taxonomic level. We provide species names for 7,727,980 (93%) records without further taxonomic verification. Software format: The entire tab-separated value (.csv) database can be downloaded and visualized at https://glowabio.org/project/epto_database/. Fifty individual datasets are also availab

Published
2023

2. Global patterns and controls of nutrient immobilization on decomposing cellulose in riverine ecosystems

Author

Costello, D. M. (David M.), Tiegs, S. D. (Scott D.), Boyero, L. (Luz), Canhoto, C. (Cristina), Capps, K. A. (Krista A.), Danger, M. (Michael), Frost, P. C. (Paul C.), Gessner, M. O. (Mark O.), Griffiths, N. A. (Natalie A.), Halvorson, H. M. (Halvor M.), Kuehn, K. A. (Kevin A.), Marcarelli, A. M. (Amy M.), Royer, T. V. (Todd, V), Mathie, D. M. (Devan M.), Albarino, R. J. (Ricardo J.), Arango, C. P. (Clay P.), Aroviita, J. (Jukka), Baxter, C. V. (Colden, V), Bellinger, B. J. (Brent J.), Bruder, A. (Andreas), Burdon, F. J. (Francis J.), Callisto, M. (Marcos), Camacho, A. (Antonio), Colas, F. (Fanny), Cornut, J. (Julien), Crespo-Perez, V. (Veronica), Cross, W. F. (Wyatt F.), Derry, A. M. (Alison M.), Douglas, M. M. (Michael M.), Elosegi, A. (Arturo), Eyto, E. (Elvira), Ferreira, V. (Veronica), Ferriol, C. (Carmen), Fleituch, T. (Tadeusz), Shah, J. J. (Jennifer J. Follstad), Frainer, A. (Andre), Garcia, E. A. (Erica A.), Garcia, L. (Liliana), Garcia, P. E. (Pavel E.), Giling, D. P. (Darren P.), Gonzales-Pomar, R. K. (R. Karina), Graca, M. A. (Manuel A. S.), Grossart, H.-P. (Hans-Peter), Guerold, F. (Francois), Hepp, L. U. (Luiz U.), Higgins, S. N. (Scott N.), Hishi, T. (Takuo), Iniguez-Armijos, C. (Carlos), Iwata, T. (Tomoya), Kirkwood, A. E. (Andrea E.), Koning, A. A. (Aaron A.), Kosten, S. (Sarian), Laudon, H. (Hjalmar), Leavitt, P. R. (Peter R.), Lemes da Silva, A. L. (Aurea L.), Leroux, S. J. (Shawn J.), LeRoy, C. J. (Carri J.), Lisi, P. J. (Peter J.), Masese, F. O. (Frank O.), McIntyre, P. B. (Peter B.), McKie, B. G. (Brendan G.), Medeiros, A. O. (Adriana O.), Milisa, M. (Marko), Miyake, Y. (Yo), Mooney, R. J. (Robert J.), Muotka, T. (Timo), Nimptsch, J. (Jorge), Paavola, R. (Riku), Pardo, I. (Isabel), Parnikoza, I. Y. (Ivan Y.), Patrick, C. J. (Christopher J.), Peeters, E. T. (Edwin T. H. M.), Pozo, J. (Jesus), Reid, B. (Brian), Richardson, J. S. (John S.), Rincon, J. (Jose), Risnoveanu, G. (Geta), Robinson, C. T. (Christopher T.), Santamans, A. C. (Anna C.), Simiyu, G. M. (Gelas M.), Skuja, A. (Agnija), Smykla, J. (Jerzy), Sponseller, R. A. (Ryan A.), Teixeira-de Mello, F. (Franco), Vilbaste, S. (Sirje), Villanueva, V. D. (Veronica D.), Webster, J. R. (Jackson R.), Woelfl, S. (Stefan), Xenopoulos, M. A. (Marguerite A.), Yates, A. G. (Adam G.), Yule, C. M. (Catherine M.), Zhang, Y. (Yixin), Zwart, J. A. (Jacob A.), Costello, D. M. (David M.), Tiegs, S. D. (Scott D.), Boyero, L. (Luz), Canhoto, C. (Cristina), Capps, K. A. (Krista A.), Danger, M. (Michael), Frost, P. C. (Paul C.), Gessner, M. O. (Mark O.), Griffiths, N. A. (Natalie A.), Halvorson, H. M. (Halvor M.), Kuehn, K. A. (Kevin A.), Marcarelli, A. M. (Amy M.), Royer, T. V. (Todd, V), Mathie, D. M. (Devan M.), Albarino, R. J. (Ricardo J.), Arango, C. P. (Clay P.), Aroviita, J. (Jukka), Baxter, C. V. (Colden, V), Bellinger, B. J. (Brent J.), Bruder, A. (Andreas), Burdon, F. J. (Francis J.), Callisto, M. (Marcos), Camacho, A. (Antonio), Colas, F. (Fanny), Cornut, J. (Julien), Crespo-Perez, V. (Veronica), Cross, W. F. (Wyatt F.), Derry, A. M. (Alison M.), Douglas, M. M. (Michael M.), Elosegi, A. (Arturo), Eyto, E. (Elvira), Ferreira, V. (Veronica), Ferriol, C. (Carmen), Fleituch, T. (Tadeusz), Shah, J. J. (Jennifer J. Follstad), Frainer, A. (Andre), Garcia, E. A. (Erica A.), Garcia, L. (Liliana), Garcia, P. E. (Pavel E.), Giling, D. P. (Darren P.), Gonzales-Pomar, R. K. (R. Karina), Graca, M. A. (Manuel A. S.), Grossart, H.-P. (Hans-Peter), Guerold, F. (Francois), Hepp, L. U. (Luiz U.), Higgins, S. N. (Scott N.), Hishi, T. (Takuo), Iniguez-Armijos, C. (Carlos), Iwata, T. (Tomoya), Kirkwood, A. E. (Andrea E.), Koning, A. A. (Aaron A.), Kosten, S. (Sarian), Laudon, H. (Hjalmar), Leavitt, P. R. (Peter R.), Lemes da Silva, A. L. (Aurea L.), Leroux, S. J. (Shawn J.), LeRoy, C. J. (Carri J.), Lisi, P. J. (Peter J.), Masese, F. O. (Frank O.), McIntyre, P. B. (Peter B.), McKie, B. G. (Brendan G.), Medeiros, A. O. (Adriana O.), Milisa, M. (Marko), Miyake, Y. (Yo), Mooney, R. J. (Robert J.), Muotka, T. (Timo), Nimptsch, J. (Jorge), Paavola, R. (Riku), Pardo, I. (Isabel), Parnikoza, I. Y. (Ivan Y.), Patrick, C. J. (Christopher J.), Peeters, E. T. (Edwin T. H. M.), Pozo, J. (Jesus), Reid, B. (Brian), Richardson, J. S. (John S.), Rincon, J. (Jose), Risnoveanu, G. (Geta), Robinson, C. T. (Christopher T.), Santamans, A. C. (Anna C.), Simiyu, G. M. (Gelas M.), Skuja, A. (Agnija), Smykla, J. (Jerzy), Sponseller, R. A. (Ryan A.), Teixeira-de Mello, F. (Franco), Vilbaste, S. (Sirje), Villanueva, V. D. (Veronica D.), Webster, J. R. (Jackson R.), Woelfl, S. (Stefan), Xenopoulos, M. A. (Marguerite A.), Yates, A. G. (Adam G.), Yule, C. M. (Catherine M.), Zhang, Y. (Yixin), and Zwart, J. A. (Jacob A.)

Abstract

Microbes play a critical role in plant litter decomposition and influence the fate of carbon in rivers and riparian zones. When decomposing low-nutrient plant litter, microbes acquire nitrogen (N) and phosphorus (P) from the environment (i.e., nutrient immobilization), and this process is potentially sensitive to nutrient loading and changing climate. Nonetheless, environmental controls on immobilization are poorly understood because rates are also influenced by plant litter chemistry, which is coupled to the same environmental factors. Here we used a standardized, low-nutrient organic matter substrate (cotton strips) to quantify nutrient immobilization at 100 paired stream and riparian sites representing 11 biomes worldwide. Immobilization rates varied by three orders of magnitude, were greater in rivers than riparian zones, and were strongly correlated to decomposition rates. In rivers, P immobilization rates were controlled by surface water phosphate concentrations, but N immobilization rates were not related to inorganic N. The N:P of immobilized nutrients was tightly constrained to a molar ratio of 10:1 despite wide variation in surface water N:P. Immobilization rates were temperature-dependent in riparian zones but not related to temperature in rivers. However, in rivers nutrient supply ultimately controlled whether microbes could achieve the maximum expected decomposition rate at a given temperature. Collectively, we demonstrated that exogenous nutrient supply and immobilization are critical control points for decomposition of organic matter.

Published
2022

3. Blue consequences of the green bioeconomy:clear-cutting intensifies the harmful impacts of land drainage on stream invertebrate biodiversity

Author

Rajakallio, M. (Maria), Jyväsjärvi, J. (Jussi), Muotka, T. (Timo), and Aroviita, J. (Jukka)

Subjects
benthic invertebrates, forestry, ecological integrity, freshwater, predictive modelling, logging, peatland drainage, clear‐cutting
Abstract

1. Growing bioeconomy is increasing the pressure to clear-cut drained peatland forests. Yet, the cumulative effects of peatland drainage and clear-cutting on the biodiversity of recipient freshwater ecosystems are largely unknown. 2. We studied the isolated and combined effects of peatland drainage and clear-cutting on stream macroinvertebrate communities. We further explored whether the impact of these forestry-driven catchment alterations to benthic invertebrates is related to stream size. We quantified the impact on invertebrate biodiversity by comparing communities in forestry-impacted streams to expected communities modelled with a multi-taxon niche model. 3.The impact of clear-cutting of drained peatland forests exceeded the sum of the independent effects of drainage and clear-cutting, indicating a synergistic interaction between the two disturbances in small streams. Peatland drainage reduced benthic biodiversity in both small and large streams, whereas clear-cutting did the same only in small streams. Small headwater streams were more sensitive to forestry impacts than the larger downstream sites. 4.We found 11 taxa (out of 25 modelled) to respond to forestry disturbances. These taxa were mainly different from those previously reported as sensitive to forestry-driven alterations, indicating the context dependence of taxonomic responses to forestry. In contrast, most of the functional traits previously identified as responsive to agricultural sedimentation also responded to forestry pressures. In particular, taxa that live temporarily in hyporheic habitats, move by crawling, disperse actively in water, live longer than 1 year, use eggs as resistance form and obtain their food by scraping became less abundant than expected, particularly in streams impacted by both drainage and clear-cutting. 5. Synthesis and applications. Drained peatland forests in boreal areas are reaching maturity and will soon be harvested. Clear-cutting of these forests incurs multiple environmental hazards but previous studies have focused on terrestrial ecosystems. Our results show that the combined impacts of peatland drainage and clear-cutting may extend across ecosystem boundaries and cause significant biodiversity loss in recipient freshwater ecosystems. This information supports a paradigm shift in boreal forest management, whereby continuous-cover forestry based on partial harvest may provide the most sustainable approach to peatland forestry.

Published
2021

4. Fungal assemblages in predictive stream bioassessment:a cross-taxon comparison along multiple stressor gradients

Author

Jyväsjärvi, J. (Jussi), Lehosmaa, K. (Kaisa), Aroviita, J. (Jukka), Turunen, J. (Jarno), Rajakallio, M. (Maria), Marttila, H. (Hannu), Tolkkinen, M. (Mikko), Mykrä, H. (Heikki), Muotka, T. (Timo), Jyväsjärvi, J. (Jussi), Lehosmaa, K. (Kaisa), Aroviita, J. (Jukka), Turunen, J. (Jarno), Rajakallio, M. (Maria), Marttila, H. (Hannu), Tolkkinen, M. (Mikko), Mykrä, H. (Heikki), and Muotka, T. (Timo)

Abstract

Degradation of freshwater ecosystems requires efficient tools for assessing the ecological status of freshwater biota and identifying potential cause(s) for their biological degradation. While diatoms and macroinvertebrates are widely used in stream bioassessment, the potential utility of microbial communities has not been fully harnessed. Using data from 113 Finnish streams, we assessed the performance of aquatic leaf-associated fungal decomposers, relative to benthic macroinvertebrates and diatoms, in modelling-based bioassessment. We built multi-taxon niche -type predictive models for fungal assemblages by using genus-based and sequence-based identification levels. We then compared the models’ precision and accuracy in the prediction of reference conditions (number of native taxa) to corresponding models for macroinvertebrates and diatoms. Genus-based fungal model nearly equalled the accuracy and precision of our best model (macroinvertebrates), whereas the sequence-based model was less accurate and tended to overestimate the number of taxa. However, when the models were applied to streams disturbed by anthropogenic stressors (nutrient enrichment, sedimentation and acidification), alone or in combination, the sequence-based fungal assemblages were more sensitive than other taxonomic groups, especially when multiple stressors were present. Microbial leaf decomposition rates were elevated in sediment-stressed streams whereas decomposition attributable to leaf-shredding macroinvertebrates was accelerated by nutrients and decelerated by sedimentation. Comparison of leaf decomposition results to model output suggested that leaf decomposition rates do not detect effectively the presence of multiple simultaneous disturbances. The rapid development of global microbial database may soon enable species-level identification of leaf-associated fungi, facilitating a more precise and accurate modelling of reference conditions in streams using fungal communities. This

Published
2021

5. Same species, same habitat preferences?:the distribution of aquatic plants is not explained by the same predictors in lakes and streams

Author

Gillard, M. B. (Morgane B.), Aroviita, J. (Jukka), and Alahuhta, J. (Janne)

Subjects
boreal water bodies, freshwater ecosystems, species distribution models, rivers, macrophytes
Abstract

1. Studying the geographical distribution of species can reveal conditions and processes that may drive species presence and abundance. Organism distribution has frequently been explained by climate, but the relative role of local environmental predictors is not fully understood. Moreover, in the freshwater realm, intrinsic differences existing between different categories of water bodies can lead to significant differences in species–environment relationships. Here, we tested the relative importance of broad‐scale climate and local environmental predictors in explaining plant species distributions in freshwater lakes and streams. 2. We built species distribution models to investigate which predictors best explain aquatic plant distribution in two categories of water bodies. We used species inventories and records of three climate and eight local environmental predictors for 150 lakes and 150 streams in Finland. 3. We found that sets of predictors that explain the distribution of macrophyte species are unique depending on if species are in a lake or a stream. Overall, air temperature and ecosystem size were essential to predict aquatic plant species presence in both water body categories. Broad‐scale climate predictors were always very important in explaining species distribution, while local environmental conditions such as water chemistry were of variable influence, depending on species and water body category. 4. These results are probably due to high spatial and temporal variability and range of water physico‐chemical parameters, especially in streams. Nonetheless, despite a lower relative importance than climatic factors, local environmental predictors also strongly affected species distributions. 5. Our findings highlight that incorporating local environmental conditions to species distribution models in addition to climate predictors is necessary to improve predictions, particularly for distribution of stream flora. Considering the species‐specific responses of aquatic plants to their environment, studying species individually with species distribution models represents a useful analysis.

Published
2020

6. Excess of nitrogen reduces temporal variability of stream diatom assemblages

Author

Huttunen, K.-L. (Kaisa-Leena), Muotka, T. (Timo), Karjalainen, S. M. (Satu Maaria), Laamanen, T. (Tiina), and Aroviita, J. (Jukka)

Subjects
Beta diversity, Community homogenization, Intra-annual, Temporal variability, Anthropogenic stress, Eutrophication
Abstract

Nutrient enrichment degrades water quality and threatens aquatic biota. However, our knowledge on (dis)similarities in temporal patterns of biota among sites of varying level of nutrient stress is limited. We addressed this gap by assessing temporal (among seasons) variation in algal biomass, species diversity and composition of diatom assemblages in three streams that differ in nutrient stress, but are otherwise similar and share the same regional species pool. We monitored three riffle sections in each stream bi-weekly from May to October in 2014. Temporal variation in water chemistry and other environmental variables was mainly synchronous among riffles within streams and often also among streams, indicating shared environmental forcing through time. We found significant differences in diatom assemblage composition among streams and, albeit less so, also among riffles within streams. Diatom assemblages in the two nutrient-enriched streams were more similar to each other than to those in the nutrient-poor stream. Taxa richness did not differ consistently among the streams, and did not vary synchronously at any spatial scale. Temporal variation in diatom assemblage composition decreased with increasing DIN:TotP ratio, likely via a negative effect on sensitive taxa while maintaining favorable conditions for certain tolerant taxa, irrespective of season. This relationship weakened but remained significant even after controlling for stochastic effects, suggesting deterministic mechanisms between nutrient levels and diatom assemblage stability. After controlling for stochastic effects temporal variability was best explained by DIN suggesting that excess of nitrogen reduces temporal variability(intra-annual beta diversity) of diatom assemblages. The high temporal variation, and especially the lack of temporal synchrony at the within streams scale, suggests that single sampling at a single site may be insufficient to reliably assess and monitor a complete stream water body. Our results also showed that measures including species identity outperform traditional diversity metrics in detecting nutrient stress in streams.

Published
2020

7. Aquatic bryophytes play a key role in sediment-stressed boreal headwater streams

Author

Turunen, J. (Jarno), Muotka, T. (Timo), Aroviita, J. (Jukka), Turunen, J. (Jarno), Muotka, T. (Timo), and Aroviita, J. (Jukka)

Abstract

Forestry-related land use can cause increasing instream sedimentation, burying and eradicating stream bryophytes, with severe ecological consequences. However, there is limited understanding of the relative roles and overall importance of the two frequently co-occurring stressors, increased fine sediments and loss of bryophytes, to stream biodiversity and ecosystem functions. By using random forest modeling and partial dependence functions, we studied the relative importance of stream bryophytes and fine sediments to multiple biological endpoints (leaf-decaying fungi, diatom, bryophyte, and benthic macroinvertebrate communities; leaf decomposition) using field survey data from headwater streams. Stream bryophyte abundance and richness were negatively related to fine sediment cover, highlighting the detrimental effect of sedimentation on bryophytes. However, bryophyte abundance was consistently more important a determinant of variation in community composition than was fine sediment cover. Leaf decomposition was influenced by shredder abundance, water temperature and, to a lesser degree, stream size. Our results suggest that the loss of stream bryophytes due to increasing sedimentation, rather than fine sediments per se, seems to be the key factor affecting multiple biological responses. Enhancing the re-establishment of bryophyte stands could partly compensate for the negative impacts of sedimentation on bryophytes and, consequently, on several other components of boreal stream ecosystems.

Published
2020

8. Is catchment geodiversity a useful surrogate of aquatic plant species richness?

Author

Toivanen, M. (Maija), Hjort, J. (Jan), Heino, J. (Jani), Tukiainen, H. (Helena), Aroviita, J. (Jukka), Alahuhta, J. (Janne), Toivanen, M. (Maija), Hjort, J. (Jan), Heino, J. (Jani), Tukiainen, H. (Helena), Aroviita, J. (Jukka), and Alahuhta, J. (Janne)

Abstract

Aim: Conserving freshwater biodiversity in a rapidly changing world requires updated planning schemes and research efforts. Geodiversity — the diversity of Earth surface forms, materials and processes — and biodiversity are interlinked at a fundamental level. This relationship is being considered in a growing number of studies, yet research from freshwater environments is scarce. We used geodiversity (rock‐type, soil‐type and geomorphological richness), local and climatic variables to explore whether geodiversity can be used as a surrogate for aquatic plant species richness in lakes and rivers. Location: Finland. Taxon: Aquatic plants. Methods: We compared geodiversity variables (measured within 1‐km² grid cells) to well‐studied local (e.g. area, alkalinity) and climate (e.g. growing degree‐days) variables, and examined the patterns between habitat types (lakes and rivers) and among all taxa and major functional groups (helophytes and hydrophytes). We modelled lake (n = 145) and river (n = 146) plant species richness with generalized linear models, and further partitioned variation to measure the independent and shared contributions of the geodiversity, climate and local environmental variable groups. As a complementary analysis, and to identify single important variables explaining variation in aquatic plant species richness, we utilized boosted regression trees. Results: We found a positive relationship between aquatic plant species richness and catchment geodiversity variation with recurring patterns across two different freshwater habitat types and two aquatic plant functional groups. Higher variation in geodiversity (measured at landscape scale) supported higher freshwater biodiversity (measured at the local scale) of lakes and rivers. Main conclusions: Geodiversity can be a useful addition to biodiversity modelling, and it should be considered in conservation schemes and monitoring efforts, further supporting the principle of conserving nature’s stage

Published
2019

9. Global patterns and drivers of ecosystem functioning in rivers and riparian zones

Author

Tiegs, S. D. (Scott D.), Costello, D. M. (David M.), Isken, M. W. (Mark W.), Woodward, G. (Guy), McIntyre, P. B. (Peter B.), Gessner, M. O. (Mark O.), Chauvet, E. (Eric), Griffiths, N. A. (Natalie A.), Flecker, A. S. (Alex S.), Acuna, V. (Vicenc), Albarino, R. (Ricardo), Allen, D. C. (Daniel C.), Alonso, C. (Cecilia), Andino, P. (Patricio), Arango, C. (Clay), Aroviita, J. (Jukka), Barbosa, M. V. (Marcus V. M.), Barmuta, L. A. (Leon A.), Baxter, C. V. (Colden V.), Bell, T. D. (Thomas D. C.), Bellinger, B. (Brent), Boyero, L. (Luz), Brown, L. E. (Lee E.), Bruder, A. (Andreas), Bruesewitz, D. A. (Denise A.), Burdon, F. J. (Francis J.), Callisto, M. (Marcos), Canhoto, C. (Cristina), Capps, K. A. (Krista A.), Castillo, M. M. (Maria M.), Clapcott, J. (Joanne), Colas, F. (Fanny), Colon-Gaud, C. (Checo), Cornut, J. (Julien), Crespo-Perez, V. (Veronica), Cross, W. F. (Wyatt F.), Culp, J. M. (Joseph M.), Danger, M. (Michael), Dangles, O. (Olivier), de Eyto, E. (Elvira), Derry, A. M. (Alison M.), Diaz Villanueva, V. (Veronica), Douglas, M. M. (Michael M.), Elosegi, A. (Arturo), Encalada, A. C. (Andrea C.), Entrekin, S. (Sally), Espinosa, R. (Rodrigo), Ethaiya, D. (Diana), Ferreira, V. (Veronica), Ferriol, C. (Carmen), Flanagan, K. M. (Kyla M.), Fleituch, T. (Tadeusz), Shah, J. J. (Jennifer J. Follstad), Frainer, A. (Andre), Friberg, N. (Nikolai), Frost, P. C. (Paul C.), Garcia, E. A. (Erica A.), Lago, L. G. (Liliana Garcia), Garcia Soto, P. E. (Pavel Ernesto), Ghate, S. (Sudeep), Giling, D. P. (Darren P.), Gilmer, A. (Alan), Goncalves, J. F. (Jose Francisco, Jr.), Gonzales, R. K. (Rosario Karina), Graca, M. A. (Manuel A. S.), Grace, M. (Mike), Grossart, H.-P. (Hans-Peter), Guerold, F. (Francois), Gulis, V. (Vlad), Hepp, L. U. (Luiz U.), Higgins, S. (Scott), Hishi, T. (Takuo), Huddart, J. (Joseph), Hudson, J. (John), Imberger, S. (Samantha), Iniguez-Armijos, C. (Carlos), Iwata, T. (Tomoya), Janetski, D. J. (David J.), Jennings, E. (Eleanor), Kirkwood, A. E. (Andrea E.), Koning, A. A. (Aaron A.), Kosten, S. (Sarian), Kuehn, K. A. (Kevin A.), Laudon, H. (Hjalmar), Leavitt, P. R. (Peter R.), Lemes da Silva, A. L. (Aurea L.), Leroux, S. J. (Shawn J.), Leroy, C. J. (Carri J.), Lisi, P. J. (Peter J.), MacKenzie, R. (Richard), Marcarelli, A. M. (Amy M.), Masese, F. O. (Frank O.), Mckie, B. G. (Brendan G.), Oliveira Medeiros, A. (Adriana), Meissner, K. (Kristian), Milisa, M. (Marko), Mishra, S. (Shailendra), Miyake, Y. (Yo), Moerke, A. (Ashley), Mombrikotb, S. (Shorok), Mooney, R. (Rob), Moulton, T. (Tim), Muotka, T. (Timo), Negishi, J. N. (Junjiro N.), Neres-Lima, V. (Vinicius), Nieminen, M. L. (Mika L.), Nimptsch, J. (Jorge), Ondruch, J. (Jakub), Paavola, R. (Riku), Pardo, I. (Isabel), Patrick, C. J. (Christopher J.), Peeters, E. T. (Edwin T. H. M.), Pozo, J. (Jesus), Pringle, C. (Catherine), Prussian, A. (Aaron), Quenta, E. (Estefania), Quesada, A. (Antonio), Reid, B. (Brian), Richardson, J. S. (John S.), Rigosi, A. (Anna), Rincon, J. (Jose), Risnoveanu, G. (Geta), Robinson, C. T. (Christopher T.), Rodriguez-Gallego, L. (Lorena), Royer, T. V. (Todd V.), Rusak, J. A. (James A.), Santamans, A. C. (Anna C.), Selmeczy, G. B. (Geza B.), Simiyu, G. (Gelas), Skuja, A. (Agnija), Smykla, J. (Jerzy), Sridhar, K. R. (Kandikere R.), Sponseller, R. (Ryan), Stoler, A. (Aaron), Swan, C. M. (Christopher M.), Szlag, D. (David), Teixeira-de Mello, F. (Franco), Tonkin, J. D. (Jonathan D.), Uusheimo, S. (Sari), Veach, A. M. (Allison M.), Vilbaste, S. (Sirje), Vought, L. B. (Lena B. M.), Wang, C.-P. (Chiao-Ping), Webster, J. R. (Jackson R.), Wilson, P. B. (Paul B.), Woelfl, S. (Stefan), Xenopoulos, M. A. (Marguerite A.), Yates, A. G. (Adam G.), Yoshimura, C. (Chihiro), Yule, C. M. (Catherine M.), Zhang, Y. X. (Yixin X.), Zwart, J. A. (Jacob A.), Tiegs, S. D. (Scott D.), Costello, D. M. (David M.), Isken, M. W. (Mark W.), Woodward, G. (Guy), McIntyre, P. B. (Peter B.), Gessner, M. O. (Mark O.), Chauvet, E. (Eric), Griffiths, N. A. (Natalie A.), Flecker, A. S. (Alex S.), Acuna, V. (Vicenc), Albarino, R. (Ricardo), Allen, D. C. (Daniel C.), Alonso, C. (Cecilia), Andino, P. (Patricio), Arango, C. (Clay), Aroviita, J. (Jukka), Barbosa, M. V. (Marcus V. M.), Barmuta, L. A. (Leon A.), Baxter, C. V. (Colden V.), Bell, T. D. (Thomas D. C.), Bellinger, B. (Brent), Boyero, L. (Luz), Brown, L. E. (Lee E.), Bruder, A. (Andreas), Bruesewitz, D. A. (Denise A.), Burdon, F. J. (Francis J.), Callisto, M. (Marcos), Canhoto, C. (Cristina), Capps, K. A. (Krista A.), Castillo, M. M. (Maria M.), Clapcott, J. (Joanne), Colas, F. (Fanny), Colon-Gaud, C. (Checo), Cornut, J. (Julien), Crespo-Perez, V. (Veronica), Cross, W. F. (Wyatt F.), Culp, J. M. (Joseph M.), Danger, M. (Michael), Dangles, O. (Olivier), de Eyto, E. (Elvira), Derry, A. M. (Alison M.), Diaz Villanueva, V. (Veronica), Douglas, M. M. (Michael M.), Elosegi, A. (Arturo), Encalada, A. C. (Andrea C.), Entrekin, S. (Sally), Espinosa, R. (Rodrigo), Ethaiya, D. (Diana), Ferreira, V. (Veronica), Ferriol, C. (Carmen), Flanagan, K. M. (Kyla M.), Fleituch, T. (Tadeusz), Shah, J. J. (Jennifer J. Follstad), Frainer, A. (Andre), Friberg, N. (Nikolai), Frost, P. C. (Paul C.), Garcia, E. A. (Erica A.), Lago, L. G. (Liliana Garcia), Garcia Soto, P. E. (Pavel Ernesto), Ghate, S. (Sudeep), Giling, D. P. (Darren P.), Gilmer, A. (Alan), Goncalves, J. F. (Jose Francisco, Jr.), Gonzales, R. K. (Rosario Karina), Graca, M. A. (Manuel A. S.), Grace, M. (Mike), Grossart, H.-P. (Hans-Peter), Guerold, F. (Francois), Gulis, V. (Vlad), Hepp, L. U. (Luiz U.), Higgins, S. (Scott), Hishi, T. (Takuo), Huddart, J. (Joseph), Hudson, J. (John), Imberger, S. (Samantha), Iniguez-Armijos, C. (Carlos), Iwata, T. (Tomoya), Janetski, D. J. (David J.), Jennings, E. (Eleanor), Kirkwood, A. E. (Andrea E.), Koning, A. A. (Aaron A.), Kosten, S. (Sarian), Kuehn, K. A. (Kevin A.), Laudon, H. (Hjalmar), Leavitt, P. R. (Peter R.), Lemes da Silva, A. L. (Aurea L.), Leroux, S. J. (Shawn J.), Leroy, C. J. (Carri J.), Lisi, P. J. (Peter J.), MacKenzie, R. (Richard), Marcarelli, A. M. (Amy M.), Masese, F. O. (Frank O.), Mckie, B. G. (Brendan G.), Oliveira Medeiros, A. (Adriana), Meissner, K. (Kristian), Milisa, M. (Marko), Mishra, S. (Shailendra), Miyake, Y. (Yo), Moerke, A. (Ashley), Mombrikotb, S. (Shorok), Mooney, R. (Rob), Moulton, T. (Tim), Muotka, T. (Timo), Negishi, J. N. (Junjiro N.), Neres-Lima, V. (Vinicius), Nieminen, M. L. (Mika L.), Nimptsch, J. (Jorge), Ondruch, J. (Jakub), Paavola, R. (Riku), Pardo, I. (Isabel), Patrick, C. J. (Christopher J.), Peeters, E. T. (Edwin T. H. M.), Pozo, J. (Jesus), Pringle, C. (Catherine), Prussian, A. (Aaron), Quenta, E. (Estefania), Quesada, A. (Antonio), Reid, B. (Brian), Richardson, J. S. (John S.), Rigosi, A. (Anna), Rincon, J. (Jose), Risnoveanu, G. (Geta), Robinson, C. T. (Christopher T.), Rodriguez-Gallego, L. (Lorena), Royer, T. V. (Todd V.), Rusak, J. A. (James A.), Santamans, A. C. (Anna C.), Selmeczy, G. B. (Geza B.), Simiyu, G. (Gelas), Skuja, A. (Agnija), Smykla, J. (Jerzy), Sridhar, K. R. (Kandikere R.), Sponseller, R. (Ryan), Stoler, A. (Aaron), Swan, C. M. (Christopher M.), Szlag, D. (David), Teixeira-de Mello, F. (Franco), Tonkin, J. D. (Jonathan D.), Uusheimo, S. (Sari), Veach, A. M. (Allison M.), Vilbaste, S. (Sirje), Vought, L. B. (Lena B. M.), Wang, C.-P. (Chiao-Ping), Webster, J. R. (Jackson R.), Wilson, P. B. (Paul B.), Woelfl, S. (Stefan), Xenopoulos, M. A. (Marguerite A.), Yates, A. G. (Adam G.), Yoshimura, C. (Chihiro), Yule, C. M. (Catherine M.), Zhang, Y. X. (Yixin X.), and Zwart, J. A. (Jacob A.)

Abstract

River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented “next-generation biomonitoring” by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.

Published
2019

10. Restoration increases transient storages in boreal headwater streams

Author

Marttila, H. (Hannu), Turunen, J. (Jarno), Aroviita, J. (Jukka), Tammela, S. (Simo), Luhta, P. (Pirkko‐Liisa), Muotka, T. (Timo), and Kløve, B. (Bjørn)

Abstract

Bed siltation can drastically alter the physical conditions of headwater streams and is therefore a stressor for stream ecosystems. We studied 32 headwater streams that represented near‐natural (reference; N = 11), sediment‐impacted (N = 12), or wood‐ (N = 4) or stone‐restored (N = 5) streams to quantify how extensive siltation and restoration with either large woody debris (LWD) or boulder structures influence transient storage conditions. We carried out repeated stream tracer experiments, field measurements of habitat characteristics, and numerical simulations to determine the effects of siltation and restoration on total transient storage. Compared with reference streams, impacted streams had a smaller storage zone cross‐sectional area (As/A) ratio and fraction of median travel time due to transient storage (F200), whereas restored streams had transient storage conditions similar to near‐natural conditions. Both of the two restoration methods had positive but differing impacts on bed sediment and transient storage properties. The LWD restoration created diverse total transient storage conditions, whereas boulder restoration decreased fine sediment cover. Addition of both LWD and boulders could thus aid the recovery of headwater streams from excessive sediment input and increase transient storage and in‐stream habitat complexity.

Published
2018

11. Dangerous relationships:biases in freshwater bioassessment based on observed to expected ratios

Author

Hämäläinen, H. (Heikki), Aroviita, J. (Jukka), Jyväsjärvi, J. (Jussi), and Kärkkäinen, S. (Salme)

Subjects
bioassessment, ecological status, reference condition approach, freshwaters, classification error, predictive models
Abstract

The ecological assessment of freshwaters is currently primarily based on biological communities and the reference condition approach (RCA). In the RCA, the communities in streams and lakes disturbed by humans are compared with communities in reference conditions with no or minimal anthropogenic influence. The currently favored rationale is using selected community metrics for which the expected values (E) for each site are typically estimated from environmental variables using a predictive model based on the reference data. The proportional differences between the observed values (O) and E are then derived, and the decision rules for status assessment are based on fixed (typically 10th or 25th) percentiles of the O/E ratios among reference sites. Based on mathematical formulations, illustrations by simulated data and real case studies representing such an assessment approach, we demonstrate that the use of a common quantile of O/E ratios will, under certain conditions, cause severe bias in decision making even if the predictive model would be unbiased. This is because the variance of O/E under these conditions, which seem to be quite common among the published applications, varies systematically with E. We propose a correction method for the bias and compare the novel approach to the conventional one in our case studies, with data from both reference and impacted sites. The results highlight a conceptual issue of employing ratios in the status assessment. In some cases using the absolute deviations instead provides a simple solution for the bias identified and might also be more ecologically relevant and defensible.

Published
2018

12. Combined effects of local habitat, anthropogenic stress, and dispersal on stream ecosystems:a mesocosm experiment

Author

Turunen, J. (Jarno), Louhi, P. (Pauliina), Mykrä, H. (Heikki), Aroviita, J. . (Jukka ), Putkonen, E. (Emmi), Huusko, A. (Ari), and Muotka, T. (Timo)

Subjects
mosses, restoration, connectivity, fungi, ecosystem function, leaf decomposition, fine sediments, community structure, benthic macroinvertebrates, macrophytes
Abstract

The effects of anthropogenic stressors on community structure and ecosystem functioning can be strongly influenced by local habitat structure and dispersal from source communities. Catchment land uses increase the input of fine sediments into stream channels, clogging the interstitial spaces of benthic habitats. Aquatic macrophytes enhance habitat heterogeneity and mediate important ecosystem functions, being thus a key component of habitat structure in many streams. Therefore, the recovery of macrophytes following in‐stream habitat modification may be prerequisite for successful stream restoration. Restoration success is also affected by dispersal of organisms from the source community, with potentially the strongest responses in relatively isolated headwater sites that receive a limited amount of dispersing individuals. We used a factorial design in a set of stream mesocosms to study the independent and combined effects of an anthropogenic stressor (sand sedimentation), local habitat (macrophytes, i.e., moss transplants), and enhanced dispersal (two levels: high vs. low) on organic matter retention, algal accrual rate, leaf decomposition, and macroinvertebrate community structure. Overall, all responses were simple additive effects with no interactions between treatments. Sand reduced algal accumulation, total invertebrate density, and density of a few individual taxa. Mosses reduced algal accrual rate and algae‐grazing invertebrates, but enhanced organic matter retention and the number of detritus and filter feeders. Mosses also reduced macroinvertebrate diversity by increasing the dominance by a few taxa. Mosses reduced leaf mass loss, possibly because the organic matter retained by mosses provided an additional food source for leaf‐shredding invertebrates and thus reduced shredder aggregation into leaf packs. The effect of mosses on macroinvertebrate communities and ecosystem functioning was distinct irrespective of the level of dispersal, suggesting strong environmental control of community structure. The strong environmental control of macroinvertebrate community composition even under enhanced dispersal suggests that re‐establishing key habitat features, such as natural stream vegetation, could aid ecosystem recovery in boreal streams.

Published
2018

13. Responses of biodiversity and ecosystem functions to land use disturbances and restoration in boreal stream ecosystems

Author

Muotka, T. (Timo), Aroviita, J. (Jukka), Turunen, J. (Jarno), Muotka, T. (Timo), Aroviita, J. (Jukka), and Turunen, J. (Jarno)

Abstract

Streams and rivers have been extensively altered by humans. Channelization and land use have changed stream habitats and water quality with adverse effects on biota and ecosystem functions. Impacted streams have been targets for restoration, but there is considerable lack of understanding how streams should be restored in an ecologically effective way. In this doctoral thesis, I studied the impacts of channelization (for timber floating) and agricultural diffuse pollution on stream biota. I also studied the effectiveness of restorations of forestry impacted streams stressed by excessive sand sedimentation from catchment drainage. Finally, I also studied the effects of mosses, fine sediment and enhanced dispersal on stream macroinvertebrate communities and ecosystem functions. I found that channelization did not have effect on diatom, macrophyte, macroinvertebrate and fish assemblages, whereas diffuse pollution had strong effects, with no interactions between the two stressors. I showed that excessive sedimentation from forest drainage was harmful for stream biota but had no effect on leaf decomposition and algal accrual rate. Restoration with boulders reduced sand cover and was more beneficial for in-stream biodiversity, whereas restoration with wood tended to increase hydrological retention of stream channels, thereby altering riparian plant assemblages toward more natural composition. In a mesocosm experiment, I found mosses to have a strong impact on macroinvertebrate communities and ecosystem functions. Mosses increased organic matter retention and reduced algal accrual rate and leaf decomposition. The effect of mosses on macroinvertebrates was stronger than that of sand sedimentation, and mosses mitigated some of the negative effects of sand. Extensive dispersal had a distinct imprint on invertebrate community composition but did not blur the effect of mosses and sand on communities, suggesting strong local-scale environmental control of composition. M, Tiivistelmä Ihmisen toiminta on laajasti muokannut virtavesiä. Uomien kanavointi ja maankäyttö ovat muuttaneet virtavesien elinympäristöjä ja veden laatua, millä on ollut haitallisia vaikutuksia virtavesien luonnon monimuotoisuuteen ja ekosysteemin toimintaan. Huonokuntoisia virtavesiä on kunnostettu paljon, mutta ymmärrys siitä, kuinka virtavesiä tulisi kunnostaa parhaan ekologisen lopputuloksen saavuttamiseksi, on edelleen vajaata. Tutkin tässä väitöskirjassa uittoperkausten ja maatalouden hajakuormituksen merkitystä ja yhteisvaikutusta virtavesien eliöyhteisöihin. Tutkin myös kunnostusten vaikutusta hiekasta kärsivissä metsätalouden muokkaamissa puroissa, sekä vesisammalten, hiekan ja eliöiden levittäytymisen merkitystä purojen pohjaeläinyhteisöjen ja ekosysteemin toimintojen muovautumisessa. Havaitsin, että uoman perkauksilla ei ollut vaikutusta virtavesien eliöyhteisöihin, mutta hajakuormituksen vaikutus oli voimakas. Perkauksella ja hajakuormituksella ei ollut yhteisvaikutuksia eliöyhteisöihin. Osoitin, että metsäojituksista aiheutuva ylimääräinen hiekan sedimentaatio on haitallista virtavesien eliöille, mutta sillä ei ollut vaikutusta lehtikarikkeen hajotukseen tai päällyslevien tuotantoon. Kunnostukset joissa käytettiin kiveä vähensivät hiekan peittävyyttä ja olivat hyödyllisempiä uoman eliöstölle kuin kunnostukset, joissa tehtiin puurakennelmia. Puukunnostukset kuitenkin lisäsivät uoman vedenpidätyskykyä ja siten muokkasivat rantavyöhykkeen kasvillisuutta luonnontilaisemmaksi. Havaitsin, että vesisammalilla on voimakas vaikutus pohjaeläinyhteisöjen koostumukseen. Sammalet vaikuttivat ekosysteemin toimintoihin lisäämällä eloperäisen aineksen pidättymistä ja vähentämällä lehtikarikkeen hajotusta ja päällyslevien tuotantoa. Sammalten vaikutus pohjaeläimiin oli voimakkaampi kuin hiekan, ja sammalet kykenivät jopa lieventämään joitakin hiekan negatiivisia vaikutuksia. Eliöiden levittäytymisellä oli selvä vaikutus yhteisöjen koostumukseen, mutta se ei hävittänyt

Published
2018

14. Responses of biodiversity and ecosystem functions to land use disturbances and restoration in boreal stream ecosystems

Author

Turunen, J. (Jarno), Muotka, T. (Timo), and Aroviita, J. (Jukka)

Subjects
diffuse pollution, virtavesikunnostukset, lajien levittäytyminen, pohjaeläimet, algal production, leaf decomposition, lehtikarikkeen hajotus, ravinteet, stream restoration, levän tuotanto, hydromorphology, hajakuormitus, sammalet, channelization, nutrients, hydromorfologia, bryophytes, sedimentaatio, mikrobit, sedimentation, dispersal, microbes, benthic macroinvertebrates
Abstract

Streams and rivers have been extensively altered by humans. Channelization and land use have changed stream habitats and water quality with adverse effects on biota and ecosystem functions. Impacted streams have been targets for restoration, but there is considerable lack of understanding how streams should be restored in an ecologically effective way. In this doctoral thesis, I studied the impacts of channelization (for timber floating) and agricultural diffuse pollution on stream biota. I also studied the effectiveness of restorations of forestry impacted streams stressed by excessive sand sedimentation from catchment drainage. Finally, I also studied the effects of mosses, fine sediment and enhanced dispersal on stream macroinvertebrate communities and ecosystem functions. I found that channelization did not have effect on diatom, macrophyte, macroinvertebrate and fish assemblages, whereas diffuse pollution had strong effects, with no interactions between the two stressors. I showed that excessive sedimentation from forest drainage was harmful for stream biota but had no effect on leaf decomposition and algal accrual rate. Restoration with boulders reduced sand cover and was more beneficial for in-stream biodiversity, whereas restoration with wood tended to increase hydrological retention of stream channels, thereby altering riparian plant assemblages toward more natural composition. In a mesocosm experiment, I found mosses to have a strong impact on macroinvertebrate communities and ecosystem functions. Mosses increased organic matter retention and reduced algal accrual rate and leaf decomposition. The effect of mosses on macroinvertebrates was stronger than that of sand sedimentation, and mosses mitigated some of the negative effects of sand. Extensive dispersal had a distinct imprint on invertebrate community composition but did not blur the effect of mosses and sand on communities, suggesting strong local-scale environmental control of composition. My thesis emphasizes that priority in stream restoration should be in the mitigation of diffuse pollution rather than restoration of channel morphology, especially in streams where channel alteration has been fairly modest, as in the case of timber floating. Addition of both boulders and large wood likely yields the best biodiversity response in the restoration of forestry impacted streams. Mosses are a key component of boreal lotic ecosystems; therefore, the recovery of mosses may be a prerequisite for the full recovery of biodiversity and ecosystem integrity of boreal streams. Tiivistelmä Ihmisen toiminta on laajasti muokannut virtavesiä. Uomien kanavointi ja maankäyttö ovat muuttaneet virtavesien elinympäristöjä ja veden laatua, millä on ollut haitallisia vaikutuksia virtavesien luonnon monimuotoisuuteen ja ekosysteemin toimintaan. Huonokuntoisia virtavesiä on kunnostettu paljon, mutta ymmärrys siitä, kuinka virtavesiä tulisi kunnostaa parhaan ekologisen lopputuloksen saavuttamiseksi, on edelleen vajaata. Tutkin tässä väitöskirjassa uittoperkausten ja maatalouden hajakuormituksen merkitystä ja yhteisvaikutusta virtavesien eliöyhteisöihin. Tutkin myös kunnostusten vaikutusta hiekasta kärsivissä metsätalouden muokkaamissa puroissa, sekä vesisammalten, hiekan ja eliöiden levittäytymisen merkitystä purojen pohjaeläinyhteisöjen ja ekosysteemin toimintojen muovautumisessa. Havaitsin, että uoman perkauksilla ei ollut vaikutusta virtavesien eliöyhteisöihin, mutta hajakuormituksen vaikutus oli voimakas. Perkauksella ja hajakuormituksella ei ollut yhteisvaikutuksia eliöyhteisöihin. Osoitin, että metsäojituksista aiheutuva ylimääräinen hiekan sedimentaatio on haitallista virtavesien eliöille, mutta sillä ei ollut vaikutusta lehtikarikkeen hajotukseen tai päällyslevien tuotantoon. Kunnostukset joissa käytettiin kiveä vähensivät hiekan peittävyyttä ja olivat hyödyllisempiä uoman eliöstölle kuin kunnostukset, joissa tehtiin puurakennelmia. Puukunnostukset kuitenkin lisäsivät uoman vedenpidätyskykyä ja siten muokkasivat rantavyöhykkeen kasvillisuutta luonnontilaisemmaksi. Havaitsin, että vesisammalilla on voimakas vaikutus pohjaeläinyhteisöjen koostumukseen. Sammalet vaikuttivat ekosysteemin toimintoihin lisäämällä eloperäisen aineksen pidättymistä ja vähentämällä lehtikarikkeen hajotusta ja päällyslevien tuotantoa. Sammalten vaikutus pohjaeläimiin oli voimakkaampi kuin hiekan, ja sammalet kykenivät jopa lieventämään joitakin hiekan negatiivisia vaikutuksia. Eliöiden levittäytymisellä oli selvä vaikutus yhteisöjen koostumukseen, mutta se ei hävittänyt hiekan ja sammalen vaikutusta, mikä viittaa korkeaan ympäristötekijöiden merkitykseen yhteisöjen rakentumisessa. Tutkielmani korostaa, että maatalousjokien tilan parantamisessa hajakuormituksen hallinta tulisi olla ensisijainen kunnostustavoite uoman rakenteen kunnostamisen sijaan. Metsätalouden vaikutuksista kärsivissä puroissa kivi- ja puumateriaalin käyttö samanaikaisesti tuottaa luultavimmin laajimman vaikutuksen purojen monimuotoisuuteen. Sammalilla on merkittävä vaikutus muiden eliöiden yhteisökoostumukseen ja ekosysteemin toimintoihin, joten sammalten palautuminen on tärkeä kunnostustavoite virtavesissä, joissa on luonnostaan paljon sammalkasvustoa.

Published
2018

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