Recent Observation of a Proliferation of Ranunculus trichophyllus Chaix. in High-altitude Lakes of the Mount Everest Region

Lacoul, P.; Freedman, Bill

doi:10.1657/1523-0430(2006)38[394:rooapo]2.0.co;2

Cited by 27 publications

(23 citation statements)

References 25 publications

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“…The study of Lacoul and Freedman (2006) indicated that the depth of the 3rd lake in the Gokyo wetlands is 45 m, which agrees with our present measurements. However, we found that the deepest lake in the series is the 4th lake with a maximum depth of 62.4 m, not the 3rd lake as indicated by Lacoul and Freedman (2006).…”

Section: Resultssupporting

confidence: 92%

“…1). These lakes are intermorainic lateral lakes connected by seepage and streams draining meltwater from the Ngozumpa Glacier on the southern slopes of Mount Cho Oyu (Tartari et al 1998a;Lacoul and Freedman 2006). The region has a monsoon climate with annual rainfall of 950-1050 mm, a monthly minimum temperature of -7.7°C in January and a maximum of 16.2°C in August (Tartari et al 1998b).…”

Section: Study Sitesmentioning

confidence: 99%

“…The watershed is dominated by exposed bedrock and glacier debris of slow-weathering gneiss and quartz-silicatic rocks (Bortolami 1998). The vegetation is comprised by patches of juniper shrubs, rhododendron, forbs, and graminoids (Lacoul and Freedman 2006). The lake sediments are silt-clay in deeper water and sand-silt in the littoral areas (Tartari et al 1998b).…”

Section: Study Sitesmentioning

confidence: 99%

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First results on bathymetry and limnology of high-altitude lakes in the Gokyo Valley, Sagarmatha (Everest) National Park, Nepal

Sharma

Bajracharya

et al. 2011

Limnology

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The aim of this study was to investigate for the first time the morphology, physical and chemical characteristics of three high-altitude lakes in the Gokyo Valley, Everest National Park, Nepal. The moraine-dammed glacial lakes were studied for three seasons to create baseline data. The second, third, and fourth lakes in the Gokyo Valley are deeper than previously assumed. The vertical profiles of temperature and dissolved oxygen indicated that the thermocline zone varied between 10 and 20 m below the surface during the post-monsoon season. Although most of the analyzed metal concentrations were below the level recommended by the WHO for safe drinking water, lead (Pb) and cadmium (Cd) levels exceeded the limits in some of the samples. This has created great concern for human health. The probable route of these two pollutants is monsoon precipitation that carries industrial pollutants along its route. The sedimentation rates of Gokyo Lakes range from 0.069 to 0.089 cm per annum, which is within the limits of other high-altitude lakes. The present findings created a baseline database for some of the remote high-altitude lakes in Nepal that can be used for lake management and for assessing future changes in lake characteristics in the Himalayan region.

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Section: Resultssupporting

confidence: 92%

Section: Study Sitesmentioning

confidence: 99%

Section: Study Sitesmentioning

confidence: 99%

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First results on bathymetry and limnology of high-altitude lakes in the Gokyo Valley, Sagarmatha (Everest) National Park, Nepal

Sharma

Bajracharya

et al. 2011

Limnology

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“…Sporadic data includes observations of the recent invasion of Ranunculus trichophyllus in high-elevation lakes in the Himalayas, considered as a signal of a warming climate (Lacoul and Freedman 2006), poleward range shifts in four freshwater taxa in UK during the recent period of climate warming (Hickling et al 2006), and some solitary observations of new occurrences at high latitudes (for Figure 6. Projected distributions, variation in probability values and probabilities of occurrence from two individual models in Finland.…”

Section: Discussionmentioning

confidence: 99%

Predicting distribution patterns and recent northward range shift of an invasive aquatic plant: Elodea canadensis in Europe

Heikkinen¹,

Leikola²,

Fronzek³

et al. 2009

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Climate data and distribution data for the Canadian waterweed Elodea canadensis Michx. from North America, whole Europe and Finland were used to investigate the ability of bioclimatic envelope models to predict the distribution range and recent northward range shift of the species in Europe. Four diff erent main types of models were developed using the North American data, including either three 'baseline' climate variables (growing degrees days, temperature of the coldest month, water balance) or an extended set of seven climate variables, both averaged either over a 30 year time slice or a longer 90 year time slice. Ten diff erent random selections of pseudo-absences were generated from the North American data, on the basis of which ten separate generalized additive models (GAMs) were developed for each main model type. All the 40 developed GAMs were applied fi rst to North America and then transferred to whole Europe and Finland. All the models showed a statistically highly signifi cant accuracy in the three study areas. Although the diff erences among the four main model types were only minor, the two extended model types showed on average statistically better performance than the two baseline models based on Bayesian information criterion (BIC) values, the amount of deviance explained by the models, resubstitution validation and four-fold cross-validation in North America. Th ey also provided slightly more accurate predictions of climatically suitable area for Elodea canadensis in Finland both in 1961-1984 and 1985-2006. However, the projections from the individual extended models were more variable than projections from the baseline models. Th us model predictions based on a variety of predictor variables but only one selection of pseudo- Heikkinen et al. / BioRisk 2: 1-32 (2009) 2 absences may be subject to biases, and outputs from multiple models should be investigated to better account for uncertainties in modelling. Overall, our results suggest that more attention should be paid to the careful selection of predictor variables and the use of multiple pseudo-absence sets in the ecological niche modelling in order to increase the reliability of the projections of the range shifts of invasive species. RESEARCH ARTICLE A peer-reviewed open-access journal Biodiversity & Ecosystem Risk Assessment

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“…The research studies carried out in the lakes and ponds of Nepal have covered various aspects of limnology (Ferro 1978, Okino & Satoh 1986, Aizaki et al 1987, Nakanishi et al 1988, Jones et al 1989, McEachern 1994, Tartari et al 1998, Rai 2000, Lacoul & Freedman 2005, plankton, macrophytes, macroinvertebrates (Manca et al 1998, Bhatt et al 1999, Dhakal 2007, Lacoul & Freedman 2006, environmental change (Lami et al 1998, Sharma et al 2009, diatoms (Hickel 1973a, b;Lohman et al 1988, Jüttner et al 1996, Rothfritz et al 1997, Cantonati et al 2001, Jüttner et al 2003, 2004, Dahal & Jüttner 2004, Simkhada 2007. Studies on the composition of vegetation surrounding the lakes have been carried out by Baral (1992), Bhattarai (1997), , Rai (1998), , Siwakoti (2006) in order to understand the habitat type.…”

Section: Study Scopementioning

confidence: 99%

Scientific Discourse of Lakes in Nepal

Bhuju

Sharma

2013

Nepal Journal of Science and Technology

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Over 5,000 standing water bodies, including those <1 ha and spread in 74 districts of Nepal have been scanned on the topographic sheets (scale of 1:125,000). Majority of these lakes or ponds are either in the high altitudes (above 3,000 m) or in lowland Tarai (below 500 m). In a literature review we found over 163 research studies conducted since the first study of lakes in 1969 in Khumbu region, majority being at the initiative of national academia, their faculties and graduate students. However, a complete inventory of Nepal's lakes is still lacking. Their characteristics and distinction from wetlands are also to be defined as the existing laws and rules do not protect lakes or ponds categorically, rather they are blanketed under wetlands and/or other river like water resources. Research observations have shown that acid depositions are the most likely source of pollution affecting high altitude lakes in the Himalayan regions during spring. Their value as religious sites has also caused anthropogenic alteration in nutrient concentrations and biological assemblages of the lake. Encroachment to the lakes/ponds is rampant to which the natural processes of sedimentation, alien species invasion or any kind of obliteration become supportive. Capacity building, knowledge generation and threat management are vital to protect these natural heritages from untimely demise.

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Recent Observation of a Proliferation of Ranunculus trichophyllus Chaix. in High-altitude Lakes of the Mount Everest Region

Cited by 27 publications

References 25 publications

First results on bathymetry and limnology of high-altitude lakes in the Gokyo Valley, Sagarmatha (Everest) National Park, Nepal

First results on bathymetry and limnology of high-altitude lakes in the Gokyo Valley, Sagarmatha (Everest) National Park, Nepal

Predicting distribution patterns and recent northward range shift of an invasive aquatic plant: Elodea canadensis in Europe

Scientific Discourse of Lakes in Nepal

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