Evaluating nitrate uptake in a Rocky Mountain stream using labelled 15N and ambient nitrate chemistry

Background aqueous chemistry and ¹⁵N_nitrate tracer injection methods were used to calculate in‐stream nitrate uptake metrics at Red Canyon Creek, a third‐order stream in the Rocky Mountains in the state of Wyoming, United States. ‘Net’ nitrate uptake lengths, which reflect both nitrate uptake and regeneration, and ‘gross’ nitrate uptake lengths, which exclude re‐mineralization, were quantified separately from background nitrate chemistry and ¹⁵N labelling tracer data, respectively. Gross nitrate uptake lengths, from tracer injections of ¹⁵N labelled nitrate, ranged from 502 to 3140 m. Net nitrate uptake lengths, from background nitrate chemistry downstream of a point source, ranged from 1170 to 4330 m. Diurnal changes in uptake lengths suggest the importance of nitrate utilization by autotrophs in the stream and benthic zone. The differences between net and gross nitrate uptake lengths along lower reaches of Red Canyon Creek allowed us to estimate the nitrate regeneration rate, which was 0·056–0·080 µmol m^?2 s^?1 during the day and 0·0062–0·0083 µmol m^?2 s^?1 at night. Spatial patterns of streambed pore water chemistry indicate those areas of the hyporheic zone where denitrification was likely occurring. Permanent log dams generated stronger redox gradients in the hyporheic zone than areas with transient beaver dams. By combining isotopically labelled nitrate additions, estimates of uptake from background aqueous nitrate chemistry and characterization of redox conditions in the hyporheic zone, we were able to determine the nitrate regeneration rate and the redox processes responsible for nitrogen cycling in the hyporheic zone. Copyright © 2010 John Wiley & Sons, Ltd.     

Relationship between dynamics of litterfall and riparian plant species in a tropical stream

We investigated the dynamics of organic matter and type of detritus in a riparian zone of the Atlantic Rain Forest domain, and specifically determined the inputs and stock of detritus contributed by plant species, and their relationship to temperature and precipitation. Our hypotheses tested were: (1) the species composition of riparian vegetation influences the amount and type of detritus delivered to a stream in an Atlantic Rain Forest, and (2) the dynamics of litterfall in the riparian zone is influenced by climate factors. The plant community was formed principally by pioneer and early successional species such as Apuleia leiocarpa, Erytrina velutina, Erytrina verna, Eucalyptus torelliana, Ficus glabra, Ficus insipida, Guarea guidonea, Guarea guidonia, Maprounea guianensis and Psidium guajava. There was a large number of G. guidonea (318 individuals/ha), followed by Cupania oblongifolia (91), Trichilia pallida (52), Piptadenia gonoacantha (26) and E. torelliana (14). G. guidonea contributed >50% of the total litterfall; however, some species which were present in high density in the plant community and did not yield significant biomass, indicating that detritus production was based on the contribution of a few species. We found 697, 856 and 804 g/m²/year from vertical, terrestrial, and lateral inputs, respectively, whereas to the annual benthic standing stock was 3257 g/m². Detritus was formed by leaves (60%), branches (32%), reproductive parts (3%), and unidentifiable fragments of organic-matter (5%). Inputs and benthic stock were markedly seasonal, with an increase of leaf litter during the dry season. Our results indicate that litterfall dynamics is basically composed of a few species that contribute with higher values of biomass. Moreover, ecological characteristics together with environmental factors can be viewed as the principal factors determining the energy balance of riparian ecosystems. The biological implications of the dynamics of organic matter have high importance for the maintenance and restoration of riparian zones. However, the amount of litterfall required to maintain the balance of the riparian community remains unclear in the tropical zone.     

高效净化氮磷污水的湿地水生植物筛选与组合

抚仙湖流域未进行生态修复的磷矿废弃地面积142×10^4m^2,对磷矿废弃地污染物流失量和区域内径流污染物含量进行调查观测,并提出磷矿废弃地水污染防治对策．富磷矿石剖面和堆土场在风化作用和降雨淋溶作用下,大量氟、磷等元素释放,造成磷矿区内地表径流和地下渗流污染结合实测的磷矿废弃地面积和土柱淋溶实验得到的污染物淋溶量,估算得到磷矿废弃地每年F和TP的淋溶流失量为60．65t／a和2734t／a,随地表径流迁移进入抚仙湖的F和TP分别为22．58t／a和7．27t／a由此可见,磷矿开采是抚仙湖的一个持久污染源,对湖泊营养化演变进程起了推动作用。     

Spatial patterns of soil nitrate in Japanese forested watersheds: importance of the near-stream zone as a source of nitrate in stream water

Spatial patterns of N dynamics in soil were evaluated within two small forested watersheds in Japan. These two watersheds were characterized by steep slopes (>30°) and high stream NO⁻₃ drainage rates (8·4 to 25·1 kg N ha⁻¹ yr⁻¹) that were greater than bulk precipitation N input rates (7·5 to 13·5 kg N ha⁻¹ yr⁻¹). Higher rates of nitrification potential at near-stream zones were reflected in greater NO⁻₃ contents for soil at the near-stream zones compared with ridge zones. Both stream discharge rates and NO⁻₃ concentrations in deep unsaturated soil at the near-stream zones were positively correlated to NO⁻₃ concentrations in stream water. These relationships, together with high soil NO⁻₃ contents at the near-stream zones, suggest that the near-stream zone was an important source of NO⁻₃ to stream water. Nitrate flux from these near-stream zones was also related to the drainage of cations (K⁺, Ca²⁺ and Mg²⁺). The steep slope of the watersheds resulted in small saturated areas that contributed to the high NO⁻₃ production (high nitrification rates) in the near-stream zone. © 1998 John Wiley & Sons, Ltd.     

Beaver dams along an agricultural stream in southern Ontario,Canada: their impact on riparian zone hydrology and nitrogen chemistry

The hydrology and nitrogen biogeochemistry of a riparian zone were compared before and after the construction of beaver dams along an agricultural stream in southern Ontario, Canada. The beaver dams increased surface flooding and raised the riparian water table by up to 1·0 m. Increased hydraulic gradients inland from the stream limited the entry of oxic nitrate‐rich subsurface water from adjacent cropland. Permeable riparian sediments overlying dense till remained saturated during the summer and autumn months, whereas before dam construction a large area of the riparian zone was unsaturated in these seasons each year. Beaver dam construction produced significant changes in riparian groundwater chemistry. Median dissolved oxygen concentrations were lower in riparian groundwater after dam construction (0·9–2·1 mg L^?1) than in the pre‐dam period (2·3–3·9 mg L^?1). Median NO₃‐N concentrations in autumn and spring were also lower in the post‐dam (0·03–0·07 mg L^?1) versus the pre‐dam period (0·1–0·3 mg L^?1). In contrast, median NH₄‐N concentrations in autumn and spring months were higher after dam construction (0·3–0·4 mg L^?1) than before construction (0·13–0·14 mg L^?1). Results suggest that beaver dams can increase stream inflow to riparian areas that limit water table declines and increase depths of saturated riparian soils which become more anaerobic. These changes in subsurface hydrology and chemistry have the potential to affect the transport and transformation of nitrate fluxes from adjacent cropland in agricultural landscapes. Copyright © 2009 John Wiley & Sons, Ltd.     

Refuge habitats for fishes during seasonal drying in an intermittent stream: movement,survival and abundance of three minnow species

Drought and summer drying can be important disturbance events in many small streams leading to intermittent or isolated habitats. We examined what habitats act as refuges for fishes during summer drying, hypothesizing that pools would act as refuge habitats. We predicted that during drying fish would show directional movement into pools from riffle habitats, survival rates would be greater in pools than in riffles, and fish abundance would increase in pool habitats. We examined movement, survival and abundance of three minnow species, bigeye shiner (Notropis boops), highland stoneroller (Campostoma spadiceum) and creek chub (Semotilus atromaculatus), during seasonal stream drying in an Ozark stream using a closed robust multi-strata mark-recapture sampling. Population parameters were estimated using plausible models within program MARK, where a priori models are ranked using Akaike’s Information Criterion. Creek chub showed directional movement into pools and increased survival and abundance in pools during drying. Highland stonerollers showed strong directional movement into pools and abundance increased in pools during drying, but survival rates were not significantly greater in pools than riffles. Bigeye shiners showed high movement rates during drying, but the movement was non-directional, and survival rates were greater in riffles than pools. Therefore, creek chub supported our hypothesis and pools appear to act as refuge habitats for this species, whereas highland stonerollers partly supported the hypothesis and bigeye shiners did not support the pool refuge hypothesis. Refuge habitats during drying are species dependent. An urgent need exists to further understand refuge habitats in streams given projected changes in climate and continued alteration of hydrological regimes.     

Effects of geomorphology and land use on stream water quality in southeastern Amazonia

Water quality in streams is determined by several factors, including geology, topography, climate, and anthropogenic changes. This study aimed to assess the effects of watershed physical, morphology, and precipitation seasonality on the water quality of two streams that supply drinking water to rural settlements and urban areas in the Cerrado-Amazonia transition region. We monitored 16 physico-chemical attributes of water at six different sample locations over three years (2013–2016). Our results indicate that eight of these physico-chemical attributes did not meet the standards for safe drinking water established by Brazilian legislation. Precipitation seasonality, degradation of riparian zones, stream length, and watershed slope were the most important predictors of impaired water quality. Our results highlight the importance of restoring and conserving riparian forests in order to maintain drinking water quality.     

Impact of redox and transport processes in a riparian wetland on stream water quality in the Fichtelgebirge region,southern Germany

Biologically mediated redox processes in the riparian zone, like denitrification, can have substantially beneficial impacts on stream water quality. The extent of these effects, however, depends greatly on the hydrological boundary conditions. The impact of hydrological processes on a wetland's nitrogen sink capacity was investigated in a forested riparian fen which is drained by a first‐order perennial stream. Here, we analysed the frequency distributions and time‐series of pH and nitrogen, silica, organic carbon and oxygen concentrations in throughfall, soil solution, groundwater and stream water, and the groundwater levels and stream discharges from a 3‐year period. During baseflow conditions, the stream was fed by discharging shallow, anoxic groundwater and by deep, oxic groundwater. Whereas the latter delivered considerable amounts of nitrogen (～0·37 mg l^?1) to the stream, the former was almost entirely depleted of nitrogen. During stormflow, near‐surface runoff in the upper 30 cm soil layer bypassed the denitrifying zone and added significant amounts to the nitrogen load of the stream. Nitrate‐nitrogen was close to 100% of deep groundwater and stream‐water nitrogen concentration. Stream‐water baseflow concentrations of nitrate, dissolved carbon and silica were about 1·6 mg l^?1, 4 mg l^?1 and 7·5 mg l^?1 respectively, and >3 mg l^?1, >10 mg l^?1 and <4 mg l^?1 respectively during discharge peaks. In addition to that macroscale bypassing effect, there was evidence for a corresponding microscale effect: Shallow groundwater sampled by soil suction cups indicated complete denitrification and lacked any seasonal signal of solute concentration, which was in contrast to piezometer samples from the same depth. Moreover, mean solute concentration in the piezometer samples resembled more that of suction‐cup samples from shallower depth than that of the same depth. We conclude that the soil solution cups sampled to a large extent the immobile soil‐water fraction. In contrast, the mobile fraction that was sampled by the piezometers exhibited substantially shorter residence time, thus being less exposed to denitrification, but predominating discharge of that layer to the stream. Consequently, assessing the nitrogen budget based on suction‐cup data tended to overestimate the nitrogen consumption in the riparian wetland. These effects are likely to become more important with the increased frequency and intensity of rainstorms that are expected due to climate change. Copyright © 2006 John Wiley & Sons, Ltd.     

Soluble iron sulfide species in natural waters: Reappraisal of their stoichiometry and stability constants

A wide range of stoichiometries has been previously proposed for soluble iron sulfide species and there is no general agreement on their importance in natural waters. The solubility of Fe(II) in 0.1 M NaClO₄ equilibrated at 20 - 0.1°C with various partial pressures of H₂S (0.1, 0.001, 0.0001, 0.00001 MPa) was measured in the pH range 3.1-7.9. Equilibrium was established within 1-6 h when amorphous FeS was the solid phase. The results could all be fitted using values for the solubility product constant (I = 0) of p*K_s = 3.00 - 0.12 and of the stability constant for a soluble Fe(HS) ₂ species (I = 0) of p#₂ = -6.45 - 0.12 where *K_s = aFe²⁺ · aHS-/aH⁺ and #₂ = aFe(HS) ₂/aFe²⁺ · (aHS^-)². Any soluble species of the form Fe_x (HS) _2x where x = &gif1; would fit the data equally well. Measurements at different partial pressures are inconsistent with labile species of the form Fe_xS_x. There was no evidence for a Fe(HS) ⁺ species. When a solution is saturated with respect to amorphous FeS, Fe(HS) ₂ will only be a significant proportion of Fe(II) when S(-II) is higher than 0.2mmoll^-1. The constants for Fe(HS) ₂ or Fe_x (HS) _2x (x S 2) are consistent with all freshwater data where constant values of measured ion activity products provide no evidence for soluble complex formation. For marine waters with high sulfide concentrations (S 6mmol l^-1), measured concentrations of Fe(II) are consistent with there being negligible soluble iron sulfide. The data are better fitted if the dissolved species are polymeric as predicted concentrations of the monomer Fe(HS) ₂ are significant. These findings suggest that rather than the dissolved species being Fe(HS) ₂, it is probably polymeric, that is Fe_x (HS) _2x (x S 2).     

Effects of land use on water column bacterial activity and enzyme stoichiometry in stream ecosystems

Fifty streams, located in southern Ontario, Canada, were visited in September 2008 to investigate the effect of varying land use, land cover, and associated resource inputs on water column bacterial abundance (BACT), production (BP), and extracellular enzyme activity and stoichiometry. Principle components analysis was used to summarize landscape data, producing three components (PCs), which explained 79.2% of the variability in the data. The PCs grouped into the following gradients: (PC1) urban land use and continuous annual cropping to wetland-like cover, (PC2) rotational cropping to forest-like cover, and (PC3) increasing rural and agricultural land uses with increasing watershed size. These landscape gradients created imbalanced resource availability. Nutrient resources were more abundant in streams with more intensive anthropogenic land uses, but carbon availability was primarily controlled by the abundance of natural land covers (wetland and wooded areas). BACT, BP, and enzyme activities were positively related primarily to nutrient availability and/or anthropogenic land use (Stepwise R ² range: 0.33?C0.73). The ratio of ??-glucosidase to alkaline phosphatase activity approached a 1:1 balance with increasing anthropogenic land use, decreased wetland and forest cover, and increased total dissolved nitrogen. The ratio of leucine-aminopeptidase to alkaline phosphatase activity approached 1:1 with both increased dissolved organic carbon and nitrogen. Moreover, enzyme C:N:P ratios moved closer to 1:1:1 with faster water column bacterial turnover times. These results suggest that water column microbial communities are better able to balance resource availability with growth in streams receiving nutrient subsidies from anthropogenic sources and under these conditions when carbon resources increase.     

Effects of ultraviolet radiation on the abundance,diversity and activity of bacterioneuston and bacterioplankton: insights from microcosm studies

The effects of ultraviolet-B (0.4 W m⁻²) radiation on the abundance, diversity and heterotrophic metabolism of bacterioneuston and bacterioplankton communities from Ria de Aveiro (Portugal) were assessed and compared to those of freshwater communities from Lake Vela (Portugal) in microcosm experiments. Exposure to 9 h of artificial ultraviolet radiation (UVR) led to 24–33% reduction in bacterial abundance and up to a 70% decrease in bacterial diversity. Maximum extracellular enzyme activity and monomer incorporation rates were reduced by 16–90% and 80–100%, respectively. Recovery of bacterial activity during post-UV dark incubations ranged from 10 to 100% for extracellular enzyme activity and 40% for monomer incorporation rates. In general, the heterotrophic activity of bacterioneuston was more inhibited by UVR than that of bacterioplankton. However, DGGE profiles revealed greater UVR-induced reductions in the diversity of bacterioplankton compared to bacterioneuston. The similarity between bacterioneuston and bacterioplankton communities in samples collected at early morning was lower than at noon (pre-exposed communities) and increased upon experimental irradiation, possibly indicating selection for UV-resistant bacteria. The observation that UV exposure resulted in enhanced reduction of bacterioneuston activity, but a lower reduction in bacterial diversity accompanied by enhanced dark recovery potential compared to bacterioplankton, indicates re-directioning of bacterioneuston metabolism towards stress defence/recovery strategies rather than the sustained heterotrophic metabolism. Our results indicate that UVR can significantly decrease the abundance, diversity and activity of bacteria inhabiting the surface and sub-surface layers of freshwater and estuarine systems with potentially important impacts on the biogeochemical cycles in these environments.     

Hydraulic habitat use with respect to body size of aquatic insect larvae: Case of six species from a French Mediterranean type stream

Macroinvertebrates play a key role in lotic ecosystems, as fish prey and processors of organic material. Therefore, their hydraulic preferences have to be integrated in instream habitat models for ecological stream management. This study characterized physical habitat use in terms of shear velocity for the larvae of three Ephemeropteran (Ephoron virgo, Oligoneuriella rhenana, and Serratella ignita), two Trichopteran (Cheumatopsyche lepida and Hydropsyche exocellata) and one Dipteran species (Blepharicera fasciata) in a Mediterranean stream at a relatively low water discharge. O. rhenana, C. lepida, H. exocellata, and B. fasciata larvae were mainly found in high shear velocity conditions, whereas E. virgo and S. ignita larvae were found in low shear velocity conditions. Knowing that habitat preferences should vary during ontogenesis (with respect to changes in biological requirements and/or morphological abilities to withstand high flow, for example), our second objective was to characterize differences in the hydraulic habitat use (in terms of shear velocity) for different size classes of these six species.Larvae of H. exocellata and B. fasciata mainly colonized high shear velocity conditions and numerous individuals of these species also used medium shear velocity conditions, independent of size class.The use of high shear velocity conditions increased with larval size for C. lepida and O. rhenana, whilst the use of low shear velocity conditions increased for larger larvae of E. virgo and S. ignita. Various hypotheses are proposed to explain these different strategies of habitat use during ontogenesis. We point out the lack of knowledge about physical habitat shifts during the larval growth of freshwater invertebrates.These results highlight the interest to consider the respective habitat requirements of different size classes of invertebrates in instream habitat models. Population bottlenecks should be overcome if hydraulic conditions are kept suitable for all size classes by stream managers.     

Water resources,their use,and water availability in Russia: Current estimates and forecasts

The results of recent studies carried out in the State Hydrological Institute were generalized to present new data on the estimation of long-term dynamics of water resources and water use for all administrative regions of RF, as well as current and anticipated variations in water resources in the nearest future. Estimates were constructed for changes in water use, load on water resources, and water availability, especially in the recent two decades, during which Russia experienced most significant changes in the major factors determining the state of water resources, i.e., climate change and socio-economic transformations. Estimates are given for constituent entities of RF and for hydroclimatic regions of the country as a whole.     

Nutrient dynamics in an alpine headwater stream: use of continuous water quality sensors to examine responses to wildfire and precipitation events

Stream water quality can change substantively during diurnal cycles, discrete flow events, and seasonal time scales. In this study, we assessed event responses in surface water nutrient concentrations and biogeochemical parameters through the deployment of continuous water quality sensors from March to October 2011 in the East Fork Jemez River, located in northern New Mexico, USA. Events included two pre‐fire non‐monsoonal precipitation events in April, four post‐fire precipitation events in August and September (associated with monsoonal thunderstorms), and two post‐fire non‐monsoonal precipitation events in October. The six post‐fire events occurred after the Las Conchas wildfire burned a significant portion of the contributing watershed (36%) beginning in June 2011. Surface water nitrate (NO₃? N) concentrations increased by an average of 50% after pre‐fire and post‐fire non‐monsoonal precipitation events and were associated with small increases in turbidity (up to 15 NTU). Beginning 1 month after the start of the large regional wildfire, monsoonal precipitation events resulted in large multi‐day increases in dissolved NO₃? N (6 × background levels), dissolved phosphate (100 × background levels), specific conductance (5 × background levels), and turbidity (>100 × background levels). These periods also corresponded with substantial sags in dissolved oxygen (<4 mg l^?1) and pH (<6.5). The short duration and rapid rates of change during many of these flow events, particularly following wildfire, highlight the importance of continuous water quality monitoring to quantify the timing and magnitude of event responses in streams and to examine large water quality excursions linked to catchment disturbance. Copyright © 2015 John Wiley & Sons, Ltd.     

Inter‐annual variability in the effects of riparian woodland on micro‐climate,energy exchanges and water temperature of an upland Scottish stream

The influence of riparian woodland on stream temperature, micro‐climate and energy exchange was investigated over seven calendar years. Continuous data were collected from two reaches of the Girnock Burn (a tributary of the Aberdeenshire Dee, Scotland) with contrasting land use characteristics: (1) semi‐natural riparian forest and (2) open moorland. In the moorland reach, wind speed and energy fluxes (especially net radiation, latent heat and sensible heat) varied considerably between years because of variable riparian micro‐climate coupled strongly to prevailing meteorological conditions. In the forested reach, riparian vegetation sheltered the stream from meteorological conditions that produced a moderated micro‐climate and thus energy exchange conditions, which were relatively stable between years. Net energy gains (losses) in spring and summer (autumn and winter) were typically greater in the moorland than the forest. However, when particularly high latent heat loss or low net radiation gain occurred in the moorland, net energy gain (loss) was less than that in the forest during the spring and summer (autumn and winter) months. Spring and summer water temperature was typically cooler in the forest and characterised by less inter‐annual variability due to reduced, more inter‐annually stable energy gain in the forested reach. The effect of riparian vegetation on autumn and winter water temperature dynamics was less clear because of the confounding effects of reach‐scale inflows of thermally stable groundwater in the moorland reach, which strongly influenced the local heat budget. These findings provide new insights as to the hydrometeorological conditions under which semi‐natural riparian forest may be effective in mitigating river thermal variability, notably peaks, under present and future climates. © 2014 The Authors. Hydrological Processes published by John Wiley & Sons Ltd.     

Ecohydrological responses to surface flow across borders: Two decades of changes in vegetation greenness and water use in the riparian corridor of the Colorado River delta

Hydrological and bioclimatic processes that lead to drought may stress plants and wildlife, restructure plant community type and architecture, increase monotypic stands and bare soils, facilitate the invasion of non-native plant species and accelerate soil erosion. Our study focuses on the impact of a paucity of Colorado River surface flows from the United States (U.S.) to Mexico. We measured change in riparian plant greenness and water use over the past two decades using remotely sensed measurements of vegetation index (VI), evapotranspiration (ET) and a new annualized phenology assessment metric (PAM) for ET. We measure these long-term (2000–2019) metrics and their short-term (2014–2019) response to an environmental pulse flow in 2014, as prescribed under Minute 319 of the 1944 Water Treaty between the two nations. In subsequent years, small-directed flows were provided to restoration areas under Minute 323. We use 250 m MODIS and 30 m Landsat imagery to evaluate three vegetation indices (NDVI, EVI, EVI2). We select EVI2 to parameterize an optical-based ET algorithm and test the relationship between ET from Landsat and MODIS by regression approaches. Our analyses show significant decreases in VIs and ET for both the 20-year and post-pulse 5-year periods. Over the last 20 years, EVI _Landsat declined 34% (30% by EVI_MODIS) and ET_Landsat-EVI declined 38% (27% by ET_MODIS-EVI), overall ca. 1.61 mm/day or 476 mm/year drop in ET; using PAM ET_Landsat-EVI the drop was from 1130 to 654 mm/year. Over the 5 years since the 2014 pulse flow, EVI_Landsat declined 20% (13% by EVI_MODIS) and ET_Landsat-EVI declined 23% (4% by ET_MODIS-EVI) with a 0.77 mm/day or a 209 mm/year 5-year drop in ET; using PAM ET_Landsat-EVI the drop was from 863 to 654 mm/year. Data and change maps show the pulse flow contributed enough water to slow the rate of loss, but only for the very short-term (1–2 years). These findings are critically important as they suggest further deterioration of biodiversity, wildlife habitat and key ecosystem services due to anthropogenic diversions of water in the U.S. and Mexico and from land clearing, fires and plant-related drought which affect hydrological processes.     

Throughfall patterns in sugarcane and riparian forest: understanding the effect of sugarcane age and land use conversion

Sugarcane is an annual crop with a dynamic canopy that changes over time mainly because of genetic adaptation. There is uncertainty about the temporal trends of throughfall (TF) in this important commercial crop. In the present paper, we used troughs to measure TF in a third and fourth ratoon and subsequently in a fourth and fifth ratoon. Additional measurements were carried out in an adjacent riparian forest. There were no significant differences between cycles of sugarcane, growth phases and riparian forest. The TF results for ratoon crop and riparian forest in 2011/2012 were 76% and 79.5% of gross rainfall, respectively, while in 2012/2013, they were 79% and 78%, respectively. However, TF was remarkably lower in the riparian forest relative to ratoon from the second half of the culm formation and elongation phase (280 days after harvest) until harvest. Copyright © 2016 John Wiley & Sons, Ltd.     

Structural characteristics of zooplankton of the Shardarinskoe Reservoir and their use in water quality assessment

Data on the Shardarinskoe Reservoir are used to assess the indicator role of zooplankton community under unstable hydrological regime. The structural characteristics of zooplankton featured significant seasonal variations. The averaged indices characterized reservoir water quality at the level of mesotrophic and eutrophic water bodies. The possible use of cyclopidas to characterize toxic pollution of water is discussed.