scholarly journals Understanding Mountain Lakes in a Changing World

Eos ◽  
2017 ◽  
Author(s):  
Isabella Oleksy ◽  
Joshua Culpepper
Keyword(s):  
Global Change ◽  
Mountain Lakes ◽  
Fort Collins ◽  
Changing World

Mountain Lakes and Global Change Workshop; Fort Collins, Colorado, 6–8 March 2017

scholarly journals Perspectives for an integrated understanding of tropical and temperate high-mountain lakes

2016 ◽  
Vol 75 (s1) ◽  
Author(s):  
Jordi Catalan ◽  
John C. Donato Rondón
Keyword(s):  
Global Change ◽  
Freshwater Ecosystems ◽  
Mountain Lakes ◽  
Molecular Techniques ◽  
Mountain Lake ◽  
Tropical Lakes ◽  
High Mountain ◽  
Essential Difference ◽  
High Mountain Lakes ◽  
High Mountain Lake

<p>High mountain lakes are extreme freshwater ecosystems and excellent sentinels of current global change. They are likely among the most comparable ecosystems across the world. The largest contrast occurs between lakes in temperate and tropical areas. The main difference arises from the seasonal patterns of heat exchange and the external loadings (carbon, phosphorus, metals). The consequence is a water column structure based on temperature, in temperate lakes, and oxygen, in tropical lakes. This essential difference implies that, in tropical lakes, one can expect a more sustained productivity throughout the year; a higher nutrient internal loading based on the mineralization of external organic matter; higher nitrification-denitrification potential related to the oxyclines; and a higher metal mobilization due to the permanently reduced bottom layer. Quantifying and linking these and other biogeochemical pathways to particular groups of organisms is in the current agenda of high-mountain limnology. The intrinsic difficulties of the taxonomic study of many of the organisms inhabiting these systems can be now overcome with the use of molecular techniques. These techniques will not only provide a much less ambiguous taxonomic knowledge of the microscopic world, but also will unveil new biogeochemical pathways that are difficult to measure chemically and will solve biogeographical puzzles of the distribution of some macroscopic organism, tracing the relationship with other areas. Daily variability and vertical gradients in the tropics are the main factors of phytoplankton species turnover in tropical lakes; whereas seasonality is the main driver in temperate communities. The study of phytoplankton in high-mountain lakes only makes sense in an integrated view of the microscopic ecosystem. A large part of the plankton biomass is in heterotrophic, and mixotrophic organisms and prokaryotes compete for dissolved resources with eukaryotic autotrophs. In fact, high-mountain lake systems are excellent model ecosystems for applying an investigation linking airshed to sediments functional views. Additionally, the study of the mountain lakes districts as functional metacommunity units may reveal key differences in the distribution of organisms of limited (slow) dispersal. We propose that limnological studies at tropical and temperate high mountain lakes should adhere to a common general paradigm. In which biogeochemical processes are framed by the airshed-to-sediment continuum concept and the biogeographical processes in the functional lake district concept. The solid understanding of the fundamental limnological processes will facilitate stronger contributions to the assessment of the impacts of the on-going global change in remote areas.</p>

Mangrove forests in a rapidly changing world: Global change impacts and conservation opportunities along the Gulf of Mexico coast

2018 ◽  
Vol 214 ◽  
pp. 120-140 ◽  
Author(s):  
Michael J. Osland ◽  
Laura C. Feher ◽  
Jorge López-Portillo ◽  
Richard H. Day ◽  
Daniel O. Suman ◽  
...  
Keyword(s):  
Global Change ◽  
Gulf Of Mexico ◽  
Mangrove Forests ◽  
Mexico Coast ◽  
Changing World

scholarly journals Enhancing Forest Productivity, Value, and Health through Silviculture in a Changing World

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1550
Author(s):  
Nelson Thiffault ◽  
Bradley D. Pinno
Keyword(s):  
Global Change ◽  
Forest Productivity ◽  
Changing World

Global change is inducing important stresses to forests worldwide [...]

scholarly journals Interactive effects of vertical mixing, nutrients and ultraviolet radiation: in situ photosynthetic responses of phytoplankton from high mountain lakes of Southern Europe

2012 ◽  
Vol 9 (7) ◽  
pp. 9791-9827
Author(s):  
E. W. Helbling ◽  
P. Carrillo ◽  
J. M. Medina-Sanchez ◽  
C. Durán ◽  
G. Herrera ◽  
...  
Keyword(s):  
Global Change ◽  
Solar Radiation ◽  
Ultraviolet Radiation ◽  
Vertical Mixing ◽  
Mountain Lakes ◽  
High Mountain ◽  
High Mountain Lakes ◽  
Phytoplankton Communities ◽  
Photosynthetic Responses

Abstract. Global change, together with human activities had resulted in increasing amounts of organic material (including nutrients) received by water bodies. This input further attenuates the penetration of solar radiation leading to the view that opaque lakes are more "protected" from solar ultraviolet radiation (UVR) than clear ones. Vertical mixing, however, complicates this view as cells are exposed to fluctuating radiation regimes, which effects have in general been neglected. Even more, the combined impacts of mixing, together with those of UVR and nutrients input are virtually unknown. In this study, we carried out in situ experiments in three high mountain lakes of Spain (Lake Enol in Asturias, and lakes Las Yeguas and La Caldera in Granada) to determine the combined effects of these three variables associated to global change on photosynthetic responses of natural phytoplankton communities. The experimentation consisted in all possible combinations of the following treatments: (a) solar radiation: UVR + PAR (280–700 nm) versus PAR alone (400–700 nm); (b) nutrient addition (phosphorus (P) and nitrogen (N)): ambient versus addition (P to reach to a final concentration of 30 μg P l−1, and N to reach a N : P molar ratio of 31) and, (c) mixing: mixed (one rotation from surface to 3 m depth (speed of 1 m every 4 min, total of 10 cycles) versus static. Our findings suggest that under in situ nutrient conditions there is a synergistic effect between vertical mixing and UVR, increasing phytoplankton photosynthetic inhibition and EOC from opaque lakes as compared to algae that received constant mean irradiance within the epilimnion. The opposite occurs in clear lakes where antagonistic effects were determined, with mixing partially counteracting the negative effects of UVR. Nutrients input mimicking atmospheric pulses from Saharan dust, reversed this effect and clear lakes became more inhibited during mixing, while opaque lakes benefited from the fluctuating irradiance regime. These climate change-related nutrients input and increased mixing would not only affect photosynthesis and production of lakes, but might also further influence the microbial loop and trophic interactions via enhanced EOC under fluctuating UVR exposure.

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