Effects of watershed liming on the soil chemistry of Woods Lake,New York

The effects of watershed liming on the exchange complex of a forest soil were investigated at Woods Lake, in the west-central Adirondack Park, New York. Attempts to neutralize lake acidity via direct application of calcite during the 1980"s were short-lived due to a short hydraulic retention time. The Experimental Watershed Liming Study (EWLS) was initiated to investigate watershed base addition as a potentially more long-term strategy for mitigation of lake acidity. In this paper we discuss the changes in the exchangeable soil complex which occurred in response to the calcite addition and attempt a mass balance for calcite applied to the watershed.An extensive sampling program was initiated for the watershed study. Soil samples were collected from pits prior to and in the two years following treatment to evaluate changes in soil chemistry. Calcite addition significantly altered the exchange complex in the organic horizon. Increases in pH caused deprotonation of soil organic matter and increases in cation exchange capacity, providing additional exchange sites for the retention of added calcium. Exchangeable acidity decreased to very low values, allowing the base saturation of upper organic horizons to increase to nearly 100 percent.Post-treatment sampling found that approximately 48 percent of the calcite remained undissolved in the soil"s Oe horizon two years later. Dissolution of the calcite was affected by field moisture conditions, with greater dissolution in wetter areas of the watershed. Mass balances calculated for calcium applied to the watershed suggest that only 4 percent of the calcium was removed through the lake outlet. Approximately 96 percent of the calcium applied remained within the watershed; as undissolved calcite, on soil exchange sites or stored in the vegetation, groundwater or surface waters of the watershed.     

Phytoplankton community structure of a deep subalpine Italian Lake (Lake Orta,N. Italy) four years after the recovery from acidification by liming

The phytoplankton succession in Lake Orta, heavy metals and ammonium polluted for decades and subjected to liming intervention in 1989–90, was studied during 1994. The existence of three main succession stages, with different structures of the community emerged. Chlorophyta are the most important taxonomic group in every season. The spring community was dominated by chlorophytes, Dinobryon sertularia and Kephyrion sp., the summer by Synedra sp. and Westella botryoides, the autumn by Rhizosolenia eriensis and W. botryoides, the winter by Synedra sp., R. eriensis and Synechococcus sp. The abundance of Chlorophyta, less important in other deep subalpine lakes, and the dominance of taxa able to thrive in polluted environments, could be related to the presence of trace metals in the sediments.     

Effect of whole catchment liming on the episodic acidification of two adirondack streams

During the fall of 1989 7.7Mg/ha of calcium carbonate was applied on two tributary catchments (40 ha and 60 ha) to Woods Lake, a small (25 ha) acidic headwater lake in the western Adirondack region of New York. Stream-water chemistry in both catchment tributaries responded immediately. Acid-neutralizing capacity (ANC) increased by more than 200 eq/L in one of the streams and more than 1000 eq/L in the other, from pre-liming values which ranged from –25 to +40 eq/L. The increase in ANC was primarily due to increases in dissolved Ca²⁺ concentrations. Most of the initial response of the streams was due to the dissolution of calcite that fell directly into the stream channels and adjacent wetlands. A small beaver impoundment and associated wetlands were probably responsible for the greater response observed in one of the streams.After the liming of subcatchmentIV (60 ha), Ca²⁺ concentrations increased with increasing stream discharge in the stream during fall rain events, suggesting a contribution from calcite dissolved within the soil and transported to the stream by surface runoff or shallow interflow. Concentrations of other ions not associated with the calcite (e.g. Na⁺) decreased during fall rain events, presumably due to mixing of solute-rich base flow with more dilute shallow interflow. The strong relation between changes in Ca²⁺ and changes in NO ₃ ^– concentrations during spring snowmelt, (r² = 0.93, slope = 0.96, on an equivalent basis) suggests that both solutes had a common source in the organic horizon of the soil. Increases in NO ₃ ^– concentrations during snowmelt were balanced by increases in Ca²⁺ that was released either directly from the calcite or from exchange sites, mitigating episodic acidification of the stream. However, high ambient NO ₃ ^– concentrations and relatively low ambient Ca²⁺ concentrations in the stream during the spring caused the stream to become acidic despite the CaCO₃ treatment.In stream WO2 (40ha), Ca²⁺ concentrations were much higher than in stream WO4 because of the dissolution of calcite which fell directly into the upstream beaver pond and its associated wetlands. Calcium concentrations decreased as both NO ₃ ^– concentrations and stream discharge increased, due to the dilution of Ca-enriched beaver pond water by shallow interflow. Despite this dilution, Ca²⁺ concentrations were high enough to more than balance strong acid anion (SO ₄ ^– , NO ₃ ^– , Cl^–) concentrations, resulting in a positive ANC in this stream throughout the year. These data indicate that liming of wetlands and beaver ponds is more effective than whole catchment liming in neutralizing acidic surface waters.     

Impacts of acidification on macroinvertebrate communities in streams of the western Adirondack Mountains,New York,USA

Limited stream chemistry and macroinvertebrate data indicate that acidic deposition has adversely affected benthic macroinvertebrate assemblages in numerous headwater streams of the western Adirondack Mountains of New York. No studies, however, have quantified the effects that acidic deposition and acidification may have had on resident fish and macroinvertebrate communities in streams of the region. As part of the Western Adirondack Stream Survey, water chemistry from 200 streams was sampled five times and macroinvertebrate communities were surveyed once from a subset of 36 streams in the Oswegatchie and Black River Basins during 2003–2005 and evaluated to: (a) document the effects that chronic and episodic acidification have on macroinvertebrate communities across the region, (b) define the relations between acidification and the health of affected species assemblages, and (c) assess indicators and thresholds of biological effects. Concentrations of inorganic Al in 66% of the 200 streams periodically reached concentrations toxic to acid-tolerant biota. A new acid biological assessment profile (acidBAP) index for macroinvertebrates, derived from percent mayfly richness and percent acid-tolerant taxa, was strongly correlated (R² values range from 0.58 to 0.76) with concentrations of inorganic Al, pH, ANC, and base cation surplus (BCS). The BCS and acidBAP index helped remove confounding influences of natural organic acidity and to redefine acidification-effect thresholds and biological-impact categories. AcidBAP scores indicated that macroinvertebrate communities were moderately or severely impacted by acidification in 44–56% of 36 study streams, however, additional data from randomly selected streams is needed to accurately estimate the true percentage of streams in which macroinvertebrate communities are adversely affected in this, or other, regions. As biologically relevant measures of impacts caused by acidification, both BCS and acidBAP may be useful indicators of ecosystem effects and potential recovery at the local and regional scale.     

Response of predatory zooplankton populations to the experimental acidification of Little Rock Lake, Wisconsin

To assess the effects of lake acidification on large predatoryzooplankton, we monitored population levels of four limnetictaxa for 6 years in a lake with two basins, one of which wasexperimentally acidified (2 years at each of three levels: pH5.6, 5.2 and 4.7). Concentrations of phantom midge (Chaoborusspp.), the most abundant large predator, remained similar inthe treatment and reference basins until the fourth year (pH5.2) when they increased in the treatment basin. In contrast,Epischuru lacustris and Leptodora kindtii disappeared from limneticsamples, and water mites declined to near zero upon acidification.Treatment basin populations of E.Iacustris declined sharplyduring the second year of acidification. The nature of the declinesuggested sensitivity of an early life stage during the firstyear at pH 5.6. Leptodora kindtii showed no population responseat pH 5.6, but declined to essentially zero at pH 5.2. Treatmentbasin populations of water mites fluctuated until decliningin the fifth and sixth years (pH 4.7). These changes indicatea variety of direct and indirect responses to lake acidification.     

Anguillicola crassus infection in Anguilla rostrata from small tributaries of the Hudson River watershed, New York, USA

We studied the invasion of the exotic nematode parasite Anguillicola crassus in the American eel Anguilla rostrata using tributaries of the Hudson River estuary. Yellow-phase American eels were sampled from 6 tributaries, and their swim bladders were examined for nematode infection. Prevalence averaged 39% with an intensity of 2.4 nematodes per eel. Parasite distribution was not significant along a latitudinal gradient; on the other hand, physical barriers (dams and natural waterfalls) significantly reduced infections upstream. Urbanization may increase the susceptibility of eels to infection; we found significantly elevated infection rates when urbanized lands exceeded 15% of the tributary catchment area. Yellow-phase eel condition was not affected by parasite infection. The invasion of the entire Hudson River watershed is ongoing and therefore will continue to be a management concern. Further analysis of the parasite-host interaction in North America is warranted.     

Atmospheric deposition and watershed nitrogen export along an elevational gradient in the Catskill Mountains, New York

Cumulative effects of atmospheric N deposition mayincrease N export from watersheds and contribute tothe acidification of surface waters, but naturalfactors (such as forest productivity and soildrainage) that affect forest N cycling can alsocontrol watershed N export. To identify factors thatare related to stream-water export of N, elevationalgradients in atmospheric deposition and naturalprocesses were evaluated in a steep, first-orderwatershed in the Catskill Mountains of New York, from1991 to 1994.Atmospheric deposition of SO ₄ ^2– , andprobably N, increased with increasing elevation withinthis watershed. Stream-water concentrations ofSO ₄ ^2– increased with increasing elevationthroughout the year, whereas stream-waterconcentrations of NO ₃ ^– decreased withincreasing elevation during the winter and springsnowmelt period, and showed no relation with elevationduring the growing season or the fall. Annual exportof N in stream water for the overall watershed equaled12% to 17% of the total atmospheric input on thebasis of two methods of estimation. This percentagedecreased with increasing elevation, from about 25%in the lowest subwatershed to 7% in the highestsubwatershed; a probable result of an upslope increasein the thickness of the surface organic horizon,attributable to an elevational gradient in temperaturethat slows decomposition rates at upper elevations. Balsam fir stands, more prevalent at upper elevationsthan lower elevations, may also affect the gradient ofsubwatershed N export by altering nitrification ratesin the soil. Variations in climate and vegetationmust be considered to determine how future trends inatmospheric deposition will effect watershed export ofnitrogen.     

An integrated framework for building trustworthy data-driven epidemiological models: Application to the COVID-19 outbreak in New York City

Epidemiological models can provide the dynamic evolution of a pandemic but they are based on many assumptions and parameters that have to be adjusted over the time the pandemic lasts. However, often the available data are not sufficient to identify the model parameters and hence infer the unobserved dynamics. Here, we develop a general framework for building a trustworthy data-driven epidemiological model, consisting of a workflow that integrates data acquisition and event timeline, model development, identifiability analysis, sensitivity analysis, model calibration, model robustness analysis, and projection with uncertainties in different scenarios. In particular, we apply this framework to propose a modified susceptible–exposed–infectious–recovered (SEIR) model, including new compartments and model vaccination in order to project the transmission dynamics of COVID-19 in New York City (NYC). We find that we can uniquely estimate the model parameters and accurately project the daily new infection cases, hospitalizations, and deaths, in agreement with the available data from NYC’s government’s website. In addition, we employ the calibrated data-driven model to study the effects of vaccination and timing of reopening indoor dining in NYC.     

Peat and solution chemistry responses to CaCO3 application in wetlands next to Woods Lake,New York

We studied the effect of a calcite (CaCO₃) treatment on peat and pore water chemistry in poor fen and conifer swamp wetlands next to Woods Lake and its tributaries to evaluate the role of wetlands in an Experimental Watershed Liming Study (EWLS). Peat was characteristically organic rich and nutrient poor, with exchangeable Ca concentrations of < 13 cmol_ckg^–1. We estimated that between 0.4 to 4 Mg (CaCO₃) ha^–1 fell directly on three study sites; however, one year after the treatment the increase in Ca concentration (0–8 cm depth) was equivalent to a (CaCO₃) dosage of 3 Mg ha^–1 with an additional 2–4 Mg ha^–1 of undissolved (CaCO₃) still present, suggesting the peat retained Ca supplied from uplands. Most aspects of peat chemistry including microbial respiration and SO₄ reduction did not respond to the treatment.Peat pore water (5 and 20 cm depths) had a mean pH of 4.82 before treatment with high concentrations of dissolved organic carbon (DOC mean of 790 mol C/l) and low Ca²⁺ concentration (mean of 32 mol/l). The (CaCO₃) treatment increased concentrations of Ca²⁺ to a mean of 87 mol/l and dissolved inorganic carbon (DIC) from 205 to a mean of 411 mol/l, whereas it decreased monomeric Al concentration from 19 to 10 mol/l. Otherwise, pore water chemistry showed little response to the treatment, at least within natural spatial and temporal variation of solute concentrations. The results suggest that liming watersheds with the relatively low (CaCO₃) dosage applied in this study can benefit acidic waters downstream by exporting more Ca and DIC and less monomeric Al, with otherwise little effect on the peat itself.     

Bioavailability and size-fraction of dissolved organic carbon, nitrogen, and sulfur at the Arbutus Lake watershed, Adirondack Mountains, NY

The heterogeneity of DOM is closely linked with the various sources and the diversity of biogeochemical processes. We studied the spatial and temporal patterns of the quantity (bioavailable [B-] and refractory concentrations by laboratory incubations) and quality (δ¹³C, aromaticity, and size-fraction by ultrafiltration [low molecular weight (LMW) < 1 kDa and high molecular weight (HMW) > 1 kDa]) of dissolved organic C (DOC), N (DON), and S (DOS) for surface waters (two upland streams, two wetland-affected streams, and lake outlet) over a 14-month period within the Arbutus Lake watershed in the Adirondack Mountains of New York State, USA. The % BDOC and % BDON of this watershed averages ranged from 6 to 18 % and from 12 to 43 %, respectively. The DOC and DON concentrations increased as water was transported through wetland areas of the Arbutus Lake watershed. DOC and DON constituents in the surface waters passing through a wetland were composed mostly of refractory HMW components (% HMWDOC: 55 %, % HMWDON: 60 %) with a higher level of aromaticity compared to upland streams (% HMWDOC: approximately 35 %, % HMWDON: approximately 30 %). DOS was dominated by the refractory (% BDOS range 6–13 %) and LMW (% LMWDOS range 62–96 %) form and we suggest that bacterial dissimilatory sulfate reduction might play an important role in generating this distinct DOS biogeochemistry. The aromaticity was positively related to total DOC concentration, but negatively to % BDOC. Arbutus Lake DOM was dominated by bioavailable and LMW characteristics, compared to wetland-affected streams where refractory and HMW DOM fractions were more prevalent. Our study suggests the different variability of DOM characteristics among elements (C, N, S) using a “bioavailability-molecular size model” showing a diagenetic perspective due to the relative refractoriness of the LMW DOS. This study also highlights the importance of multiple approaches for understanding DOM biogeochemistry with respect to molecular size, bioavailability, aromaticity, stoichiometry, isotopic values, and elemental concentrations.     

Photosynthetic characteristics of Myriophyllum spicatum and six submersed aquatic macrophyte species native to Lake George, New York

SUMMARY.

• 1 The macrophyte community of Lake George, New York is diverse, composing of forty-eight submersed species representing a wide range of habitats, depth ranges and life-history strategies. The photosynthetic rates of seven representative submersed aquatic macrophytes were determined in laboratory studies using measurements of short-term changes in oxygen concentration at eight light intensities from 0 to 1000 μmol m^?2 s^?1 at 20°C. The species examined were: Elodea canadensis, Myriophyllum spicatum, Potamogeton amplifolius, P. gramineus, P. praelongus, P. robbinsii, and Vallisneria americana.
• 2 Comparisons of maximum net photosynthesis, Michaelis–Menten V_max and K_m for photosynthesis versus irradiance, and dark respiration rates correlated with changes in community composition and species distribution with depth.
• 3 In particular, Myriophyllum spicatum exhibited a high photosynthetic rate (V_max) and high light requirement (both in compensation point and higher half-saturation constant (K_m) indicative of a high light-adapted species. In contrast, the native species exhibited shade-tolerant characteristics.
• 4 Simple daily carbon balance models indicate that M. spicatum has a higher positive carbon balance near the surface than the native species, but carbon balance decreased more rapidly with decreased light. All species showed greatly reduced carbon balances under a simulated M. spicatum canopy, indicating that native species might not survive. Myriopyllum spicatum leaves would experience self-shading and eventual sloughing.

     

Fluctuations in the muskellunge (Esox masquinongy Mitchill) population of Chautauqua Lake,New York

Synopsis Population and exploitation estimates were made from angler recaptures of Chautauqua Lake muskellunge,Esox masquinongy Mitchill. Fish were tagged during Conservation Department studies in 1941–1946, 1961–1965 and 1976–1978. Population estimates of adult fish ranged from one to seven fish per hectare and angler exploitation rates of tagged fish fluctuated from 3.8% to 14.1%. Relative catch indicators suggest a major decline in the lake's muskellunge population during the last decade. Overexploitation, habitat alteration and interspecific competition with recently introduced fish species were cited as probable causes of the decline.     

Combining system dynamic model and CLUE-S model to improve land use scenario analyses at regional scale: A case study of Sangong watershed in Xinjiang,China

Uses of models of land use change are primary tools for analyzing the causes and consequences of land use changes, assessing the impacts of land use change on ecosystems and supporting land use planning and policy. However, no single model is able to capture all of key processes essential to explore land use change at different scales and make a full assessment of driving factors and impacts. Based on the multi-scale characteristics of land use change, combination and integration of currently existed models of land use change could be a feasible solution. Taken Sangong watershed as a case study, this paper describes an integrated methodology in which the conversion of land use and its effect model (CLUE), a spatially explicit land use change model, has been combined with a system dynamic model (SD) to analyze land use dynamics at different scales. A SD model is used to calculate area changes in demand for land types as a whole while a CLUE model is used to transfer these demands to land use patterns. Without the spatial consideration, the SD model ensures an appropriate treatment of macro-economic, demographic and technology developments, and changes in economic policies influencing the demand and supply for land use in a specific region. With CLUE model the land use change has been simulated at a high spatial resolution with the spatial consideration of land use suitability, spatial policies and restrictions to satisfy the balance between land use demand and supply. The application of the combination of SD and CLUE model in Sangong watershed suggests that this methodology have the ability to reflect the complex behaviors of land use system at different scales to some extent and be a useful tool for analysis of complex land use driving factors such as land use policies and assessment of its impacts on land use change. The established SD model was fitted or calibrated with the 1987–1998 data and validated with the 1998–2004 data; combining SD model with CLUE-S model, future land use scenarios were analyzed during 2004–2030. This work could be used for better understanding of the possible impacts of land use change on terrestrial ecosystem and provide scientific support for land use planning and managements of the watershed.     

The seasonal cycle of inorganic carbon species in Cazenovia Lake,New York, 1977 *

SUMMARY. Spatial and temporal distributions of inorganic carbon and related ionic species (Ca²⁺, H⁺) were monitored weekly for 1 year in Cazenovia Lake, a small mesotrophic marl lake. Attendant [H₂CO*₃]([H₂CO₃] + [CO₂(aq)]) and CaCO₃ equilibrium conditions were determined through application of equilibrium equations adjusted for appropriate temperatures and ionic strength. A seasonal cycle was demonstrated for the inorganic carbon species which was temporally correlated to the lake's thermal and productivity cycles. Vertical homogeneity in carbonate chemistry was evident during turnover periods while dramatic differences developed between the epilimnion and hypolimnion during winter and summer stratification. The lake was supersaturated throughout the year with H₂CO*₃, though saturation was approached during the productive summer months in the epilimnion. The epilimnion was supersaturated with respect to CaCO₃, from the start of spring turnover to the end of autumn turnover. Calcium (Ca²⁺) levels within the epilimnion decreased through much of the same period. Dissolution of CaCO₃ in the hypolimnion is indicated by increases in Ca²⁺ and alkalinity as stratification periods progress. Analysis of potentially influencing factors indicates that the seasonal trends were mostly a result of CO₂ metabolism. This was further supported by concurrent algal biomass and ¹⁴C uptake.     

Characterization of Thrombolitic Bioherm Cyanobacterial Assemblages in a Meromictic Marl Lake (Fayetteville Green Lake,New York)

The Fayetteville Green Lake is a small (0.258 km²) meromictic marl lake that is host to a thrombolitic bioherm inhabited by coccoid and filamentous cyanobacteria. To date there has been only limited study of bioherm cyanobacterial community ecology, and none focusing on their molecular diversity. Samples of the bioherm were collected along vertical and spatial transects on a portion of the thrombolite in early fall 2010. Cyanobacterial assemblage spatial variability and operational taxonomic unit composition was analyzed by automated rRNA intergenic spacer analysis (ARISA). A total of 123 cyanobacterial ARISA operational taxonomic units were observed across all fingerprints. Cyanobacterial assemblages were variable across depth and spatial gradients, and may be structured by gradients in light availability and habitat stability. Cyanobacterial community fingerprints were more taxonomic unit rich, diverse, and had greater fingerprint similarity in deeper samples than those at the surface. Several operational taxonomic units were common to all samples taken, while the majority of assemblage components were heterogeneous between transects and depths. Hence, our results suggest that cyanobacterial communities on the thrombolite in Green Lake represent a mixture of taxa that are selected for by prevailing physicochemical conditions, while other taxa are selected for on spatial scales of meters and may represent more specialized cyanobacteria on the thrombolite. Moreover, our data suggest that the depth-dependent structure of bioherm cyanobacterial assemblages may be a consequence of habitat conditions, which may include light intensity and quality, temperature variation and habitat stability.     

A survey of waterfowl for echinostomes and schistosomes from Lake Wanaka and the Waitaki River watershed, New Zealand

Waterfowl from Lake Wanaka and the Waitaki Lakes watershed of New Zealand's South Island were surveyed to find natural hosts with adult echinostomes and schistosomes to provide sufficient numbers of eggs for laboratory studies. The Canada goose (Branta canadensis) was found to host an echinostome determined to be a New Zealand strain of Echinostoma revolutum. The New Zealand scaup (Aythya novaeseelandia) concurrently hosts three species of echinostomes (E. revolutum, Echinoparyphium cinctum and E. recurvatum) plus two species of avian schistosomes (Trichobilharzia sp. and Dendritobilharzia pulverulenta). In the Canada goose and the New Zealand scaup, adult gravid echinostomes predominated over juveniles. In other waterfowl surveyed, very few echinostomes were found, with juveniles predominating.     

希腊莱斯沃斯岛中新世木化石研究进展

希腊莱斯沃斯岛是世界上最为著名的木化石产地之一,出露有由中新世火山活动而形成的大规模矿化森林,保存有大量的植物以及部分动物化石。其中大多数木化石横卧或直立原地埋藏,并保留比较完整的根系,是目前保存最完整的新生代矿化森林生态系统。本文对莱斯沃斯岛已报道的木化石进行详细梳理分析,共计8科15属32种,包括裸子植物6科11属22种,被子植物2科4属10种,并着重介绍了发现自莱斯沃斯的代表性木化石特有类群系统古生物学属性。通过木化石反映的植物类群,初步恢复莱斯沃斯岛中新世属于北半球亚热带气候,总体比较温暖潮湿,有着明显的季节性变化特征。最后对莱斯沃斯岛木化石的埋藏环境进行了简要讨论,并对今后的研究进行了展望。