The power of the past: using sediments to track the effects of multiple stressors on lake ecosystems

2010 ◽  
Vol 55 ◽  
pp. 43-59 ◽  
Author(s):  
JOHN P. SMOL
Keyword(s):  
Multiple Stressors ◽  
Lake Ecosystems ◽  
The Past

A paleolimnological investigation of the effects of forest fire on lake water quality in northwestern Ontario over the past ca. 150 years

2002 ◽  
Vol 80 (12) ◽  
pp. 1329-1336 ◽  
Author(s):  
Andrew M Paterson ◽  
David S Morimoto ◽  
Brian F Cumming ◽  
John P Smol ◽  
Julian M Szeicz
Keyword(s):  
Water Quality ◽  
Forest Fire ◽  
Biological Response ◽  
Species Assemblage ◽  
Lake Water Quality ◽  
Lake Ecosystems ◽  
Fire Scar ◽  
The Past ◽  
Study Lake ◽  
Drainage Ratio

Fire is an important mechanism of disturbance in boreal ecosystems; however, the effects of fire on lake ecosystems are still not well understood. This study provides a detailed assessment of the impacts of fire on the limnology of a small oligotrophic lake (Lake 42), located approximately 200 km northwest of Thunder Bay, Ont. The study lake is characterized by a small drainage ratio (watershed area : surface area) and a relatively long water residence time. Age establishment and fire scar analyses determined that at least one, and perhaps two, major fires had burned to the lake's shoreline in the past ca. 150 years. Using a paleoecological approach, diatoms were examined in a 210Pb-dated sediment core. Following watershed fires, minimal changes were noted in the diatom species assemblage. These findings may be explained by the low sedimentation rates and small drainage ratio of the study lake, although other studies suggest that the biological response may be minimal compared with physical–chemical responses in some ecosystems. Beginning in the early 1980s, however, distinct changes were noted in the species assemblage and in diatom-inferred total phosphorus. Our findings suggest that the study lake may be more sensitive to precipitation inputs of nutrients than to inputs resulting from watershed disturbances.Key words: paleolimnology, diatoms, forest fire, water quality.

scholarly journals Control and remediation methods for eutrophic lakes in the past 30 years

2020 ◽  
Vol 81 (6) ◽  
pp. 1099-1113 ◽  
Author(s):  
Yuan Zhang ◽  
Pingping Luo ◽  
Shuangfeng Zhao ◽  
Shuxin Kang ◽  
Pengbo Wang ◽  
...  
Keyword(s):  
New Technologies ◽  
Management Strategies ◽  
Cyanobacterial Blooms ◽  
Small Scale ◽  
Short Term ◽  
Eutrophic Lakes ◽  
Lake Ecosystems ◽  
The Past ◽  
Incomplete Removal

Abstract Accelerated eutrophication, which is harmful and difficult to repair, is one of the most obvious and pervasive water pollution problems in the world. In the past three decades, the management of eutrophication has undergone a transformation from simple directed algal killing, reducing endogenous nutrient concentration to multiple technologies for the restoration of lake ecosystems. This article describes the development and revolution of three remediation methods in application, namely physical, chemical, and biological methods, and it outlines their possible improvements and future directions. Physical and chemical methods have obvious and quick effects to purify water in the short term and are more suitable for small-scale lakes. However, these two methods cannot fundamentally solve the eutrophic water phenomenon due to costly and incomplete removal results. Without a sound treatment system, the chemical method easily produces secondary pollution and residues and is usually used for emergency situations. The biological method is cost-effective and sustainable, but needs a long-term period. A combination of these three management techniques can be used to synthesize short-term and long-term management strategies that control current cyanobacterial blooms and restore the ecosystem. In addition, the development and application of new technologies, such as big data and machine learning, are promising approaches.

scholarly journals Dynamics of Murray-Darling floodplain forests under multiple stressors: The past, present, and future of an Australian icon

2011 ◽  
Vol 47 (12) ◽  
Author(s):  
Ralph Mac Nally ◽  
Shaun C. Cunningham ◽  
Patrick J. Baker ◽  
Gillis J. Horner ◽  
James R. Thomson
Keyword(s):  
Multiple Stressors ◽  
Floodplain Forests ◽  
The Past

scholarly journals Find the future from the past: Paleolimnology in Indonesia

2018 ◽  
Vol 31 ◽  
pp. 08002 ◽  
Author(s):  
Tri Retnaningsih Soeprobowati ◽  
Sri Widodo Agung Suedy ◽  
Hadiyanto
Keyword(s):  
Human Activities ◽  
Inductively Coupled Plasma ◽  
Lake Ecosystem ◽  
Ecosystem Monitoring ◽  
Climate History ◽  
Lake Ecosystems ◽  
Inductively Coupled ◽  
The Past ◽  
Floral Diversity ◽  
The Future

Agriculture, hydro electricity power, fisheries, source of drinking water, recreation, and industrial use has led to wide-spread impairment of Indonesia surface waters. Indonesia is rich with various freshwaters, including 840 unique lakes with different size and types, 735 ponds, and 162 dams that covering about 21,000 km2 of area, contain about 500 km3 of water functions as both economically and ecologically purposes. Indonesia is also one of the biggest listed freshwater endemic species in Asia. However, an increase of population and human activities affect a decrease in quantity and quality of several lake ecosystems that able to induce the destruction up to extinction of the lake ecosystem. An increase of lake utilization, with partial management system without considering the preservation and sustainability of ecosystem had reduced lake functions. Paleolimnological approach is one of science and technological approach to support the successfull of grand design of Indonesian lakes conservation and rehabilitation, specifically on the program of lakes’ development ecosystem monitoring, evaluation, and information system. The studied on (paleo) limnology in Indonesia had been collected and compared. The vertical distribution of trace elements of Ni, Mg, and B were analyzed by Inductively Coupled Plasma (ICP) with mass spectrophotometry for 44 cm sediment core from Telaga Pengilon Dieng, Java. The paleolimnological studies in Indonesia have been limited, particularly for Indonesian as the first author. Lakes’ sediment records the changes condition of catchment area, like a diary book. Reconstruction of the past environmental condition is required to predict the future condition. This can be done using the organism preserved in the sediment, such as diatoms and pollen. Diatoms are unicellular algae that are used extensively in paleoecology. The diatom assemblages in sedimentary records can make direct and indirect inferences about past environmental conditions. The palynological data on the terrestrial and aquatic ecosystem are used as an indicator of recent and paleoecological changes, particularly on the climate, history and floral diversity. Paleolimnological analysis increasingly attention is being given to developing the technique to model human activities.

scholarly journals A window to the world of global insect declines: Moth biodiversity trends are complex and heterogeneous

2021 ◽  
Vol 118 (2) ◽  
pp. e2002549117
Author(s):  
David L. Wagner ◽  
Richard Fox ◽  
Danielle M. Salcido ◽  
Lee A. Dyer
Keyword(s):  
Costa Rica ◽  
Multiple Stressors ◽  
Abiotic Factors ◽  
Dispersal Ability ◽  
Considerable Time ◽  
Geographic Ranges ◽  
Continental Scale ◽  
The Past ◽  
Abundance And Diversity

Moths are the most taxonomically and ecologically diverse insect taxon for which there exist considerable time-series abundance data. There is an alarming record of decreases in moth abundance and diversity from across Europe, with rates varying markedly among and within regions. Recent reports from Costa Rica reveal steep cross-lineage declines of caterpillars, while other sites (Ecuador and Arizona, reported here) show no or only modest long-term decreases over the past two decades. Rates of decline for dietary and ecological specialists are steeper than those for ecologically generalized taxa. Additional traits commonly associated with elevated risks include large wingspans, small geographic ranges, low dispersal ability, and univoltinism; taxa associated with grasslands, aridlands, and nutrient-poor habitats also appear to be at higher risk. In temperate areas, many moth taxa limited historically by abiotic factors are increasing in abundance and range. We regard the most important continental-scale stressors to include reductions in habitat quality and quantity resulting from land-use change and climate change and, to a lesser extent, atmospheric nitrification and introduced species. Site-specific stressors include pesticide use and light pollution. Our assessment of global macrolepidopteran population trends includes numerous cases of both region-wide and local losses and studies that report no declines. Spatial variation of reported losses suggests that multiple stressors are in play. With the exception of recent reports from Costa Rica, the most severe examples of moth declines are from Northern Hemisphere regions of high human-population density and intensive agriculture.

scholarly journals Stress Induced Cardiomyopathy (Takotsubo) in a Post-Operative Pregnancy Induced Hypertension Patient Operated for Caesarean Section: A Case Report

2021 ◽  
pp. 146-150
Author(s):  
Shweta Takalkar ◽  
Pratibha Deshmukh ◽  
Sweety Pasari ◽  
Priyanka Deshmukh ◽  
Vivek Chakole
Keyword(s):  
Case Report ◽  
Caesarean Section ◽  
Psychiatric Illness ◽  
Multiple Stressors ◽  
Mode Of Delivery ◽  
Pregnancy Induced Hypertension ◽  
Acute Blood Loss ◽  
The Past ◽  
Induced Hypertension ◽  
History Of

This is a case of a 30 year old female, with Pregnancy Induced Hypertension and history of psychiatric illness in the past, subsequently developed TCM in the intra-operative period. ECG showed subtle fresh changes. There were multiple stressors for our patient namely acute blood loss, spinal anaesthesia and history of psychiatric illness. The decision on the timing and mode of delivery should be guided by obstetrical reasons. A multidisciplinary team of cardiologists, obstetricians, neonatologists, and psychologists should be involved. This case highlights the importance of being extra vigilant in patients having psychiatric disorders undergoing any surgical procedure especially caesarean section.

Carbon budgets of boreal lakes: state of knowledge, challenges, and implications

2015 ◽  
Vol 23 (3) ◽  
pp. 275-287 ◽  
Author(s):  
M.U. Mohamed Anas ◽  
Kenneth A. Scott ◽  
Björn Wissel
Keyword(s):  
Boreal Forest ◽  
Carbon Balance ◽  
Multiple Stressors ◽  
Boreal Lakes ◽  
Landscape Context ◽  
Carbon Budgets ◽  
Lake Ecosystems ◽  
Environmental Perturbations ◽  
Forest Biome

Converging evidence suggests that freshwater systems play an important role in the carbon cycles at both regional and global scales. In addition, there are serious concerns that ongoing and future changes to the environment could alter these dynamics. This is particularly important in the boreal forest biome, which contains a very high density of lakes. In this review, we synthesize the current state of research to provide a critical overview of (i) the role of boreal lakes as emitters versus sinks of carbon, (ii) their contribution to the regional carbon balance, (iii) knowledge gaps that may inhibit an accurate evaluation of the role of boreal lakes in a landscape context, and (iv) impacts of environmental perturbations on carbon dynamics in boreal lakes. Several recent studies indicate that boreal lakes are actively processing, emitting, and storing carbon rather than being passive transport conduits. Yet, generalizing the role of lake ecosystems for the overall carbon balance of the boreal forest biome is challenging because of the scarcity of studies on lake carbon budgets in a landscape context that can capture the potential temporal and spatial variability and uncertainties associated with the available estimates of carbon pools and fluxes. Further, environmental perturbations, such as climate change, acidic deposition, and nutrient enrichment, likely affect both carbon export to lakes and in-lake carbon processing in boreal regions. Predicting their overall impacts on lake carbon budgets is particularly difficult, not only because individual environmental stressors likely affect multiple processes involved in carbon cycling, but also because often multiple stressors act synergistically or antagonistically at the landscape level. Accordingly, long-term, system-wide approaches are required to accurately evaluate the importance of lakes for boreal carbon budgets in a changing environment.

Observations of the continuum near the galactic centre

1967 ◽  
Vol 31 ◽  
pp. 405
Author(s):  
F. J. Kerr
Keyword(s):  
Galactic Centre ◽  
The Past ◽  
Centre Region ◽  
The Continuum

A continuum survey of the galactic-centre region has been carried out at Parkes at 20 cm wavelength over the areal11= 355° to 5°,b11= -3° to +3° (Kerr and Sinclair 1966, 1967). This is a larger region than has been covered in such surveys in the past. The observations were done as declination scans.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

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