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Trends in biodiversity research over two decades: paradigmatic finders keepers?

Biodiversity research has been criticized for displaying the "founder effect" and not deviating in terms of study topic from the course set by its founding terrestrial ecologists more than three decades ago. I tested this hypothesis by examining over four thousand papers published between 1987 and 2008 in three international journals, Conservation Biology, Biological Conservation, and Biodiversity and Conservation. Analysis of temporal trends in types of organisms studied, types of ecosystems studied, types of methodologies used, and types of stresses investigated, revealed that there has been little movement away from the origins of the profession as being primarily concerned with the effects of forest habitat loss on charismatic terrestrial megafauna.

Differentiation of concentration level of iron compounds in water reservoirs in subsidence depressions in the Katowice Upland

The aim of investigations was to evaluate the influence of varied anthropopression on the concentration of iron compounds in water reservoirs located in subsidence depressions treated as geosystems. Investigations were carried out during period of three hydrological years 2003-2005 within 10 reservoirs located in the Katowice Upland. The presence of iron was systematically measured in water and one time in bottom deposits. Measurements in taken samples were made by means of spectrometer of atomic absorption SOLAAR M6. Results confirmed varied influence of anthropopression on concentration of iron compounds in described reservoirs. It refers to waters and bottom deposits as well. Large differences between reservoirs occurred in a case of iron concentration in bottom deposits. The smallest amounts of it (3.10 g kg-1) were stated in transfer (flow-through) reservoir in Sosnowiec. Maximum values occurred also in reservoir in Sosnowiec, and the level of iron concentration in its deposits amounted to 44.28 g kg-1. Waters were also characterized by varied level of iron concentration. The lowest average values (0.0437 mg Fe l-1) were typical for one of reservoirs in Sosnowiec, whereas the maximum average iron concentration in amount of 0.4331 mg Fe l-1 referred to one of reservoirs in Zabrze. In the described reservoirs dynamic temporal changes in iron concentration in limnic waters was also stated. In every reservoir periods of complete disappearance of this metal occurred, whereas the maximum amounts of it in particular objects changed from 0.1132 mg Fe l-1 in reservoir in the borderland of Bytom and Chorzów up to 1.3744 mg Fe l-1 in reservoir located in Zabrze. The presence of iron compounds in the described water reservoirs on the one hand is shaped by environmental conditions, but on the other hand varied influence of anthropopression decides significantly of their spatial and temporal cycle in the nature.

Abstract

Various factors influence the spatial and temporal patterns of land cover and land use in lakeland landscapes. Land use/cover change (LUCC) is one of the crucial factors influencing both natural processes that occur in lakelands and lakes and anthropogenic processes, which intensify these changes. Therefore, LUCC at a local and regional scale may be treated as an important geoindicator for the functioning of the lakeland landscape. Nowadays, LUCC mostly depends on different human decisions. In the existing literature, the consequences of negative changes have already been widely recognized. Conversely, in this paper, we focus on the possible positive effects of LUCC. To that end, we built an agent-based model to show how selected human decisions may positively influence lakeland landscapes and lakes. We apply the model to the Gniezno Lakeland, Poland. Based on the environmental decisions of farmers, the model demonstrates how the LUCC pattern may change in time and space and how those changes may influence freshwater quality in four individual lake catchments of the Gniezno Lakeland.

The variability of phosphorus fractions in sediments of a shallow, restored Antoninek Reservoir (Poznań, Poland)

Spatial and temporal variability of phosphorus (P) fractions content in bottom sediments of a shallow preliminary reservoir was studied in Antoninek, situated in Poznań. Fractions were analyzed at least once in a season (more often in spring and summer) between August 2004 and November 2005 according to the fractioning protocol proposed by Psenner et al. (1988). Circa 10 cm thick sediment layers were collected from three study sites, situated along the main axis of the reservoir. The contribution of NH4Cl-P and BD-P, i.e. the most accessible fractions biologically was similar at all stations (usually below 10%). The share of other fractions increased according to the sequence NaOH-RP < NaOH-NRP < HCl-P < Res-P. Only at station 1 the amount of phosphorus related to organic matter was lower than with aluminum. The domination of Res-P fraction indicated that the main part of phosphorus in sediment is biologically unavailable, therefore the intensity of phosphorus loading from sediments shall be low. However, high organic matter content, noted in sediments of Antoninek Reservoir, determined great amount of NaOH-NRP fraction. Both parameters remained under the influence of mats of macroalgae, growing intensively in the reservoir during vegetation season. The role of sediments as a source of phosphorus for water column enlarged, due to increased organic matter decomposition, especially in periods of high water temperature in this shallow reservoir.

Abstract

Interdisciplinary studies on environmental evolution during the last 650 years based on the analysis of mill pond deposits have been conducted in the valley of the Jarosławianka Stream (left-bank tributary of the River Wieprza). According to historical data, confirmed also by radiocarbon dating, the water mill was located in the valley in 1351 and operated until the 1960s. The sequence of stratified deposits with a thickness of up to about 2 metres was accumulated in mill pond basin during this period. The vertical variability in the physical and chemical properties of these deposits reflects temporal environmental changes in the catchment, particularly the intensity of chemical and mechanical denudation and human activity. Analysis of subfossil Cladocera suggests four phases in the development of the mill pond. Changing along with the intensity of the pond basin water flow, redox and nutritional conditions are reflected in the spatial variability of deposits, especially their textural parameters, pH and abundance in organic carbon, nitrogen and carbonates.

Abstract

The aim of this study was a recognition of the carbon cycle in a small anthropogenic reservoir located in Wrocław (SW Poland). The research investigated the geochemical processes and isotopic interactions in the water column as well as those between the water column and the sediment. Moreover, an attempt was made to identify the sources of carbon in the studied water body. Observations of temporal and spatial (vertical and horizontal) geochemical trends were the subject of this research. Chemical and isotopic analyses were the main tool used in this study. A total of 49 samples of water, sediment and plants were prepared, with sampling carried out in the period from October 2015 to May 2017. Two periods: autumn and spring were chosen for the study. During the autumn cycle, smaller variations in the values of δ13C in DIC were found compared to the spring cycle. The enrichment of dissolved inorganic carbon (DIC) in the heavy isotope during the spring period was caused by the dynamic growth of microorganisms. The process of assimilative reduction of dissolved inorganic carbon by aquatic organisms, which use inorganic carbon in biochemical reactions, occurred in the reservoir. This process led to an enrichment of DIC in the 13C isotope. The analysis of the sedimentary organic carbon revealed a greater enrichment in the heavy isotope of carbon (by about 3‰) in April compared to May. This is due to the growth of microorganisms responsible for degradation of sedimentary organic matter and plant detritus. The sediment and the water column were shown to interact through the exchange of carbon.

Variability of bio-optical parameters in Lake Jasień Północny and Lake Jasień Południowy

Bio-optical properties of water in two lakes from the Bytow district, Jasień Południowy (JS) and Jasień Północny (JN), were measured between 2007 and 2010. These lakes were chosen as reference for research in the Regional Environment Monitoring System (Wojewódzki Program Monitoringu Środowiska) between 2007 and 2009. The research concerned mainly OSCs (Optically Significant Constituents) such as chlorophyl a, SPM (Suspended Particulate Matter), CDOM (Colored Dissolved Organic Matter) and optical parameters of water (Secchi depth zSD, diffuse light attenuation coefficient Kd, PAR). The aim of this article is to present temporal variability of OSC and optical properties in the investigated lakes as well as the relation between OSCs and the optical properties of water. The research has shown that the variability in the properties of water of these lakes is quite significant: concentration of chlorophyl CChl varied from 1.3 to 32.3 mg m-3 and the Kd, PAR coefficient from 0.42 to 1.05 m-1. The obtained results were compared with the same parameters from other lakes in this region. The variability in the optical properties depend on the season and the biological activity of phytoplankton. Regression analyses showed a high correlation of optical properties of water with CChl and CSPM, and no correlation with CDOM concentration. The highest determination coefficient was obtained for the optical parameters correlated with the three OSCs. The presented results show not only annual variability and variability between the years but also an influence of OSC elements on the optical properties of lakes.

Abstract

Ecological variation of the selected subpopulations of Iris sibirica L. were studied in the years 2011-2012, in the abandoned patches of Molinietum caeruleae dominated by small meadow species (Patch I), macroforbs (Patch II), largetussock grasses (Patch III), shrubs (Patch IV), as well as shrubs and trees (Patch V). The abundance of subpopulations and dimensions of aggregations of ramet clusters increased gradually from Patch I to Patch IV and subsequently declined in Patch V. During the whole study period, all subpopulations showed signs of senility due to the absence of individuals in prereproductive stages. The share of generative ramet clusters diminished, while contribution of senile and fragmentised ramet clusters increased substantially in consecutive patches. The dimensions of ramet clusters increased significantly in successive plots and years. The number and height of generative stems and production of flowers and fruits did not show the temporal variability. The abundance of generative stems was considerably lower in the plots dominated by small meadow species, than in the sites dominated by large-tussock grasses, shrubs or overgrown shrubs and trees. Both the height of flowering stems and production of flowers and fruits increased gradually from Patch I, via Patches II, III and IV, to Patch V. The augmentation of flower production might contribute to better visibility of inflorescences for pollinators, whereas an increase in the production of fruits may increase the chances for successful seed dispersal to new sites.

This study results show that the I. sibirica subpopulations occurring in the site dominated by small meadow species and macroforbs were in unsatisfactory condition, those inhabiting the sites dominated by large-tussock grasses and shrubs were in a quite good condition, while the subpopulation inhabiting the plot overgrown by shrubs and trees showed the worst condition

Abstract

High mountain ecosystems, with strong topographic and climatic gradients, are fragile and particularly sensitive to changes in land use. The abandonment of historic cultural landscapes has often led to changes in the pattern of land cover and thus, to a shift in the functions of high mountain landscapes, like fresh water supply, productivity or erosion control. In order to understand the effects of land-use change on the land-cover pattern at the local and regional scale, we analyzed and classified the mountainous landscape structure in the Kazbegi region in Georgia, located in the Central Greater Caucasus. For 13 settlements, we determined the land cover as present in 1987 and 2015, and quantified the changes over time to detect land-cover development trends for each settlement. Using a cluster analysis, the study area was analyzed regarding to topography (altitude, aspect, slope) and distance to settlements at the regional scale to gain six groups with separating conditions. Furthermore, each settlement was classified according to topography and land-cover change to obtain site-specific, comparative development trends. Our results show that this Caucasian high-mountain landscape is characterized by open grassland (67%) used as pasture and hay meadow, and natural birch forests (7%) in patches in the upper half of the subalpine belt. Within the settlements but also in their surroundings, field vegetables are cultivated in home gardens (1%). Land-cover change during the observation period mainly affected the cultural grassland with hay meadow abandonment. Moreover, shrubbery and forest expanded considerably on abandoned pastures. We further detected a strong relationship to topography that considerably varied between settlements resulting in specific trends in land-use change. Hay-making and arable land cultivation are focused today on sun-exposed and gentle slopes near the settlements. Shrub encroachment and reforestations were localized on farther distances and mostly on north-exposed slopes. Besides providing basic information about the historic and current land-use and land-cover patterns, our results quantify the landscape change during almost 30 years. A spatio-temporal analysis revealed an understanding of how land-use decisions influence the landscape pattern. In the context of societal development, regional socioeconomic processes, like shifts in the agricultural structure and population outmigration, seem to be societal drivers of changes. Our findings reveal linkages and interrelationships between natural, human-induced environmental and socioeconomic processes within high-mountain socio-ecological systems. Moreover, we suggest that sustainable land-use strategies for spatial development on sub-regional level, especially in marginal high-mountain regions, should consider topography and its influence on land-use change.

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