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1.
Jes Jessen Rasmussen Annette Baattrup-Pedersen Tenna Riis Nikolai Friberg 《Aquatic Ecology》2011,45(2):231-242
We surveyed macrophyte community structure and measured community metabolism and nutrient uptake along a temperature gradient
(9.7–17.4°C) in four Icelandic streams influenced by geothermal heating. The study streams are part of the geothermal area
in Hengill that is uniquely characterised by streams with comparable water chemistry despite the geothermal influence. Stream
metabolism was studied applying the diurnal upstream–downstream dissolved oxygen change technique. Nutrient uptake was studied
by adding solutions of nitrogen and phosphorus together with a conservative tracer. Rates of primary production (GPP) and
uptake of nitrate–N and phosphate-P increased with increasing stream temperature. GPP was 20 times higher (up to 12.99 g O2 m−2 day−1) and rates of nutrient uptake were up to 30-times higher (up to 22.99, 13.31 and 7.94 mg m−2 h−1 for ammonium, nitrate and phosphate, respectively) in the warmest streams compared with the coldest. Furthermore, macrophytes,
when present, were strongly controlling ecosystem processes. Our study implies that temperature may affect stream ecosystem
processes both directly (i.e. physiologically) and indirectly (i.e. by changing other structural parameters). 相似文献
2.
Macrophyte communities in unimpacted European streams: variability in assemblage patterns, abundance and diversity 总被引:5,自引:5,他引:0
Annette Baattrup-Pedersen Krzysztof Szoszkiewicz Rebi Nijboer Mattie O’Hare Teresa Ferreira 《Hydrobiologia》2006,566(1):179-196
Macrophytes are an important component of aquatic ecosystems and are used widely within the Water Framework Directive (WFD)
to establish ecological quality. In the present paper we investigated macrophyte community structure, i.e., composition, richness
and diversity measures in 60 unimpacted stream and river sites throughout Europe. The objectives were to describe assemblage
patterns in different types of streams and to assess the variability in various structural and ecological metrics within these
types to provide a basis for an evaluation of their suitability in ecological quality assessment. Macrophyte assemblage patterns
varied considerably among the main stream types. Moving from small-sized, shallow mountain streams to medium-sized, lowland
streams there was a clear transition in species richness, diversity and community structure. There was especially a shift
from a predominance of species-poor mosses and communities dominated by liverwort in the small-sized, shallow mountain streams
to more species-rich communities dominated by vascular plants in the medium-sized, lowland streams. The macrophyte communities
responded to most of the features underlying the typological framework defined in WFD. The present interpretation of the WFD
typology may not, however, be adequate for an evaluation of stream quality based on macrophytes. First and most important,
by using this typology we may overlook an important community type, which is characteristic of small-sized, relatively steep-gradient
streams that are an intermediate type between the small-sized, shallow mountain streams and the medium-sized, lowland streams.
Second, the variability in most of the calculated metrics was slightly higher when using the pre-defined typology. The consistency
of these results should be investigated by analysing a larger number of sites. Particularly the need of re-defining the typology
to improve the ability to detect impacts on streams and rivers from macrophyte assemblage patterns should be investigated.
Electronic supplementary material Electronic supplementary material is available for this article at
and accessible for authorised users. 相似文献
3.
Mattie T. O’Hare Annette Baattrup-Pedersen Rebi Nijboer Krzysztof Szoszkiewicz Teresa Ferreira 《Hydrobiologia》2006,566(1):197-210
The impact of altering hydro-morphology on three macrophyte community types was investigated at 107 European stream sites.
Sites were surveyed using standard macrophyte and habitat survey techniques (Mean Trophic Rank Methodology and River Habitat
Survey respectively). Principal Components Analysis shows the macrophyte community of upland streams live in a more structurally
diverse physical habitat than lowland communities. Variables representing the homogeneity and diversity of the physical environment
were used to successfully separate un-impacted from impacted sites, e.g. homogeneity of depth and substrate increased with
decreasing quality class for lowland sites (ANOVA p < 0.05). Macrophyte attribute groups and structural metrics such as species richness were successfully linked to hydro-morphological
variables indicative of impact. Most links were specific to each macrophyte community type, e.g., the attribute group liverworts,
mosses and lichens decreased in abundance with increasing homogeneity of depth and decreasing substrate size at lowland sites
but not at upland sites. Elodea canadensis, Sparganium emersum and Potamogeton crispus were indicative of impacted lowland sites. Many of the indicator species are also known to be tolerant to other forms of
impact. The potential for a macrophyte tool indicative of hydro-morphological impact is discussed. It is concluded one could
be constructed by combining indicator species and metrics such as species richness and evenness. 相似文献
4.
Aquatic mosses are important primary producers in High-Arctic lakes, but little information is available on their contribution to the overall production in these lakes. In order to predict effects of climate change on whole-lake ecosystem characteristics, more knowledge is needed on the role of moss in primary production, the extent of nutrient limitation of moss primary production and whether moss serves as food resource for secondary producers. In this study, we conducted an in situ growth experiment of an aquatic moss in a High-Arctic lake in NE Greenland and used these data to determine annual net production of this moss in the whole lake. We also measured tissue-N and tissue-P in order to assess nutrient limitation of moss production, measured in situ decomposition rates by litter bag experiments over 1 year and assessed the role of moss as food source by analysing stable isotope 15N and 13C of relevant organism groups in the lake. Net primary production of moss was 1.3 gC m?2 year?1 and constituted 23 % of the total benthic primary production and 18 % of the total lake primary production. Stoichiometric assessments suggested N and P limitation of moss growth. On average, 15 % of the standing biomass was decomposed per year. Our results also indicate that moss is not directly used as food resource by herbivores, but the most abundant herbivore, Lepidurus arcticus, is feeding on the epiphytic biofilm on the moss. Moss biomass is instead incorporated into the microbial decomposer pathway. All together, the study shows that moss plays an important ecological role as primary producer in High-Arctic lakes and functions as substrate for periphytic biofilm that serves as food resource for important herbivore invertebrates. 相似文献
5.
Emma?G?theEmail author Allan?Timmermann Kathrin?Januschke Annette?Baattrup-Pedersen 《Hydrobiologia》2016,783(1):79-91
Most river restoration projects have applied relatively small-scale measures focused on improving specific instream conditions, with only limited outcomes for biodiversity in rivers and their adjacent riparian habitats. Here, we investigate the effects of both small- and large-scale restoration projects on floodplain vegetation across 20 European catchments. We focused on the roles of different restoration parameters (i.e., the number, spatial extent and type of restoration measure applied and restoration age) and specific environmental characteristics in regulating changes in plant diversity and trait composition following restoration. Among restoration characteristics, restoration type was the only significant determinant of plant community responses, with stream channel widening having the strongest effects, particularly on the diversity and composition of species traits favoured by increases in physical disturbance (e.g. flooding) and open habitat patch availability (e.g. plant growth form, life strategy and life span). Of the environmental variables, altitude and discharge were positively and most strongly related to responses of both species and trait diversity. Our results emphasise the value of (i) choosing relevant restoration measures that affect environmental conditions of importance for the target organism group and (ii) conducting restoration projects in environmental settings where the likelihood of restoration “success” is maximised. 相似文献
6.
Teixeira-de Mello Franco Meerhoff Mariana González-Bergonzoni Ivan Kristensen Esben Astrup Baattrup-Pedersen Annette Jeppesen Erik 《Environmental Biology of Fishes》2016,99(1):133-144
Environmental Biology of Fishes - The characteristics of riparian vegetation along streams vary with natural and anthropogenic factors. Deforestation for agricultural purposes has consequences for... 相似文献
7.
Long-term effects of stream management on plant communities in two Danish lowland streams 总被引:1,自引:1,他引:0
Submerged macrophytes grow abundantly in most shallow streams common in the cultivated lowlands of northwestern Europe. Weed-cutting has been practised for years in many of these streams to reduce the risk of flooding of adjacent land. Our objective was to quantify long-term impacts of weed-cutting on macrophyte communities in two Danish rivers. We found that the total macrophyte coverage was similar in the weed-cut and uncut reaches in the two rivers, but species richness, diversity and patch complexity were higher in the uncut reaches. The spatial distribution of macrophytes on the stream bottom was also more heterogeneous in the uncut stream reaches. We also found evidence of a strong effect of weed-cutting on macrophyte species composition. P. natans was abundant in the uncut reaches in both streams but practically eliminated in the cut reaches, despite the fact that its basic habitat requirements were met. Also, the established phase strategy of the macrophyte community was affected by weed-cutting. Species displaying characteristically ruderal traits were more abundant in the cut reaches and species with competitive abilities were only abundant in the uncut stream reaches. We suggest that important species traits in streams, where the weed is cut regularly, are associated with rapid growth and high dispersal-capacity. Our results indicate that weed-cutting can contribute significantly to a decline in species diversity in streams. To provide optimal conditions for diverse stream macrophyte communities, we therefore suggest that weed-cutting should be minimised. 相似文献
8.
Andrea Oddershede Cyrille Violle Annette Baattrup-Pedersen Jens-Christian Svenning Christian Damgaard 《Journal of Plant Ecology》2019,12(2):327
Aims
For temperate regions such as Northern Europe, predicted climate change patterns include an increase in winter precipitation causing increased risk of flooding, whereas periods of droughts will become more frequent in summer. The aim of this study is to explore variations in plant functional trait distributions along a hydrological gradient spanning from recurrent drought events to recurrent flooding—mimicking future precipitation patterns. 相似文献
9.
Buffer strip width and agricultural pesticide contamination in Danish lowland streams: Implications for stream and riparian management 总被引:1,自引:0,他引:1
Jes J. Rasmussen Annette Baattrup-Pedersen Peter Wiberg-Larsen Ursula S. McKnight Brian Kronvang 《Ecological Engineering》2011,37(12):1990-1997
According to the European Water Framework Directive, member states are obliged to ensure that all surface water bodies achieve at least good ecological status and to identify major anthropogenic stressors. Non-point source contamination of agricultural pesticides is widely acknowledged as one of the most important anthropogenic stressors in stream ecosystems.We surveyed the occurrence of 31 pesticides and evaluated their potential toxicity for benthic macroinvertebrates using Toxic Units (TU) in 14 Danish 1st-and 2nd-order streams in bed sediments and stream water during storm flow and base flow. Total pesticide concentrations and toxic potential were highest during storm flow events with maximum TU ranging from −6.63 to −1.72. We found that minimum buffer strip width in the near upstream area was the most important parameter governing TU. Furthermore, adding a function for minimum buffer strip width to the Runoff Potential (RP) model increased its power to predict measured TUs from 46% to 64%. However, including a function for tile drainage capacity is probably equally important and should be considered in future research in order to further optimise the RP model. Our results clearly emphasise the importance of considering buffer strips as risk mitigation tools in terms of non-point source pesticide contamination. We furthermore apply our results for discussing the minimum dimensions that vegetated buffer strips should have in order to sufficiently protect stream ecosystems from pesticide contamination and maintain good ecological status. 相似文献
10.