https://www.jlimnol.it/jlimnol/issue/feedJournal of Limnology2024-02-27T13:13:17+00:00Nadia Moscatonadia.moscato@pagepress.orgOpen Journal Systems<p>The <strong>Journal of Limnology</strong> publishes peer-reviewed original papers, review papers and notes about all aspects of limnology. The scope of the Journal of Limnology comprises the ecology, biology, microbiology, physics, and chemistry of freshwaters, including the impact of human activities, management and conservation. Coverage includes molecular-, organism-, community-, and ecosystem-level studies on both applied and theoretical issues. Proceedings of workshops, specialized symposia, conferences, may also be accepted for publication.</p>https://www.jlimnol.it/jlimnol/article/view/2106Sediment biomarkers record hydrological and anthropogenic-driven environmental changes since 1800 AD in the Ili-Balkhash Basin, arid Central Asia2024-02-27T13:13:17+00:00Hongliang Zhang2638253535@qq.comJinglu Wuw.jinglu@niglas.ac.cnLong Mamalong@ms.xjb.ac.cnShuie Zhanzhanshuie@126.comMiao Jinmjin@niglas.ac.cnZhangdong Jin zhdjin@ieecas.cn<p>Human activity and hydroclimate change greatly influence the environment in a lake and its catchment, particularly in areas with fragile ecosystems, such as arid Central Asia. In this study, lipid biomarkers (<em>n</em>-alkanes and<em> n</em>-fatty acids) were measured in a <sup>210</sup>Pb- and <sup>137</sup>Cs-dated sediment core from Lake Balkhash to determine their environmental significance and infer the history of environmental change over the last ~200 years. The terrestrial origin of long-chain <em>n</em>-alkanes and the aquatic origin of both <em>n</em>-fatty acids and mid-/short-chain <em>n</em>-alkanes were inferred from molecular distributions and diagnostic ratios. Three major environmental phases were identified over the past two centuries based on stratigraphic shifts in biomarker indicators. During 1800-1860 AD, the lake exhibited a high-water level with abundant submerged/floating macrophytes and limited phytoplankton, as suggested by multiple indicators, e.g., high proportions of aquatic macrophytes (Paq) and long-chain <em>n</em>-fatty acids (L-FAs). Overall, minor terrestrial inputs were revealed by low concentrations of long-chain <em>n</em>-alkanes (L-ALKs), suggesting dense vegetation cover in the catchment. The lake environment experienced a pronounced change in the subsequent phase from 1860–1930 AD, during which the cover of submerged/floating macrophytes gradually diminished, as revealed by the decreasing trend of aquatic proxies, e.g., L-FAs and Paq. In contrast, the number of emergent plants and terrestrial inputs increased, as suggested by the decreased Paq values. A great variation in water levels likely resulted in the shrinkage of the submerged/floating macrophyte cover. During 1930-2017 AD, anthropogenic impacts began to appear on the sediment profile. The highest terrestrial inputs, as revealed by the maximum L-ALK abundance on record, indicated intensive exploitation of the catchment during 1935-1959 AD. The lowest L-FA and Paq values suggested that submerged/floating macrophytes were at the lowest levels during this phase, possibly in response to the decreased water levels and increasing salinity. Increased human-induced nutrient loading coupled with elevated regional temperature prompted the lake to become an increasingly productive lake system, especially in more recent decades, as indicated by the highest levels of short-chain lipids. These results highlight the important role of hydrological variation and human activity in the environmental evolution of the Ili-Balkhash Basin.</p>2024-02-27T00:00:00+00:00Copyright (c) 2024 The Author(s)https://www.jlimnol.it/jlimnol/article/view/2167How the catchment-river-lake continuum shapes the downstream water quality2024-01-31T08:43:38+00:00Sirje Vilbastesirje.vilbaste@emu.eePeeter Pallpeeter.pall@emu.eeMarina Haldnamarina.haldna@emu.eePeeter Nõgespeeter.noges@emu.eeKai Piirsookai.piirsoo@emu.eeTiina Nõgestiina.noges@emu.ee<p>Lakes play a crucial role in the nutrient cycling of Earth, despite covering only a small fraction of the planet’s surface. Their interactions with their surrounding catchment areas significantly impact ecosystems and regulatory services. The connection between a lake and its catchment, especially the drainage ratio (catchment area to lake surface area), shapes the characteristics of lakes and their response to catchment processes. Within the catchment area, geological, land cover, and land use factors influence the composition of stream water that flows into the lake. These factors play a role in transporting various substances, both organic and inorganic, to the streams. Lakes act as dynamic filters, altering the chemical composition of water that flows through them. This study aims to investigate how a large, shallow lake impacts the quality of the river water as it passes through. It builds on an analysis of nutrient (carbon, nitrogen, phosphorus, silicon) fluxes into Lake Võrtsjärv, using six years of monthly monitoring data from five main inflows and the outflow. The research explores how catchment characteristics and hydrology affect nutrient concentrations and loadings into the lake, as well as the retention or release of substances by the lake. Findings reveal that catchment characteristics, such as land use and forest cover, significantly influence water quality parameters. Different inflows showed variations in water quality, and annual variations were observed, largely correlated with precipitation and discharge. Võrtsjärv plays a critical role in retaining or releasing nutrients, with varying impacts depending on the water budget of the lake. In years with a positive water balance, the lake retains all nutrients, whereas in dry years only inflowing N and P loads exceed their outflow. Overall, this study underscores the importance of lakes as integral components of catchment ecosystems, shedding light on their complex interactions with the environment and the implications for water quality. It emphasizes the need for careful consideration of land use and hydrological factors in managing and preserving these vital aquatic systems.</p>2024-01-31T00:00:00+00:00Copyright (c) 2024 The Author(s)