Warming exacerbates the impact of nutrient enrichment on microbial functional potentials important to the nutrient cycling in shallow lake mesocosms

2021 ◽  
Author(s):  
Lijuan Ren ◽  
Yuanyuan Liu ◽  
Torben L. Lauridsen ◽  
Martin Søndergaard ◽  
Boping Han ◽  
...  
Keyword(s):  
Nutrient Cycling ◽  
Shallow Lake ◽  
Nutrient Enrichment ◽  
The Impact

scholarly journals Spatial and Temporal Distribution of Cattle Dung and Nutrient Cycling in Integrated Crop–Livestock Systems

Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 672
Author(s):  
Sandoval Carpinelli ◽  
Adriel Ferreira da Fonseca ◽  
Pedro Henrique Weirich Neto ◽  
Santos Henrique Brant Dias ◽  
Laíse da Silveira Pontes
Keyword(s):  
Nutrient Cycling ◽  
Temporal Distribution ◽  
Nutrient Release ◽  
Cattle Dung ◽  
Total N ◽  
Light Reduction ◽  
Residue Decomposition ◽  
Thiessen Polygon ◽  
The Impact ◽  
Livestock Systems

Residue decomposition from cattle dung is crucial in the nutrient cycling process in Integrated Crop–Livestock Systems (ICLS). It also involves the impact of the presence of trees exerted on excreta distribution, as well as nutrient cycling. The objectives of this research included (i) mapping the distribution of cattle dung in two ICLS, i.e., with and without trees, CLT and CL, respectively, and (ii) quantification of dry matter decomposition and nutrient release (nitrogen—N, phosphorus—P, potassium—K, and sulphur—S) from cattle dung in both systems. The cattle dung excluded boxes were set out from July 2018 to October 2018 (pasture phase), and retrieved after 1, 7, 14, 21, 28, 56 and 84 days (during the grazing period). The initial concentrations of N (~19 g kg−1), P (~9 g kg−1), K (~16 g kg−1), and S (~8 g kg−1) in the cattle dung showed no differences. The total N, P, K and S released from the cattle dung residues were less in the CLT system (2.2 kg ha−1 of N; 0.7 kg ha−1 of P; 2.2 kg ha−1 of K and 0.6 kg ha−1 of S), compared to the CL (4.2 kg ha−1 of N; 1.4 kg ha−1 of P; 3.6 kg ha−1 of K and 1.1 kg ha−1 of S). Lesser quantities of cattle dung were observed in the CLT (1810) compared to the CL (2652), caused by the lower stocking rate, on average, in this system (721 in the CL vs. 393 kg ha−1 in the CLT) because of the reduced amount of pasture in the CLT systems (−41%), probably due to light reduction (−42%). The density of the excreta was determined using the Thiessen polygon area. The CL system revealed a higher concentration of faeces at locations near the water points, gate and fences. The CLT affects the spatial distribution of the dung, causing uniformity. Therefore, these results strengthen the need to understand the nutrient release patterns from cattle dung to progress fertilisation management.

Soil Type Modifies the Impacts of Warming and Snow Exclusion on Carbon and Nutrient Losses

2021 ◽  
Author(s):  
Stephanie M. Juice ◽  
Paul G. Schaberg ◽  
Alexandra M. Kosiba ◽  
Carl E. Waite ◽  
Gary J. Hawley ◽  
...  
Keyword(s):  
Climate Change ◽  
Nutrient Cycling ◽  
Soil Type ◽  
Soil Characteristics ◽  
Nutrient Loss ◽  
Climate Projections ◽  
Nutrient Losses ◽  
N Losses ◽  
Total N ◽  
The Impact

Abstract The varied and wide-reaching impacts of climate change are occurring across heterogeneous landscapes. Despite the known importance of soils in mediating biogeochemical nutrient cycling, there is little experimental evidence of how soil characteristics may shape ecosystem response to climate change. Our objective was to clarify how soil characteristics modify the impact of climate changes on carbon and nutrient leaching losses in temperate forests. We therefore conducted a field-based mesocosm experiment with replicated warming and snow exclusion treatments on two soils in large (2.4 m diameter), in-field forest sapling mesocosms. We found that nutrient loss responses to warming and snow exclusion treatments frequently varied substantially by soil type. Indeed, in some cases, soil type nullified the impact of a climate treatment. For example, warming and snow exclusion increased nitrogen (N) losses on fine soils by up to four times versus controls, but these treatments had no impact on coarse soils. Generally, the coarse textured soil, with its lower soil-water holding capacity, had higher nutrient losses (e.g., 12-17 times more total N loss from coarse than fine soils), except in the case of phosphate, which had consistently higher losses (23-58%) from the finer textured soil. Furthermore, the mitigation of nutrient loss by increasing tree biomass varied by soil type and nutrient. Our results suggest that potentially large biogeochemical responses to climate change are strongly mediated by soil characteristics, providing further evidence of the need to consider soil properties in Earth system models for improving nutrient cycling and climate projections.

scholarly journals Influence of Bio-Pollution on Ecosystem Processes: The Impact of Introduced Lake Trout on Streams, Predators, and Forests in Yellowstone National Park

2002 ◽  
Vol 26 ◽  
pp. 71-77
Author(s):  
Jamie Crait ◽  
Merav Ben-David ◽  
Bob Hall
Keyword(s):  
Nutrient Cycling ◽  
Yellowstone National Park ◽  
National Park ◽  
Lake Trout ◽  
Cutthroat Trout ◽  
Terrestrial Ecosystems ◽  
Spawning Migration ◽  
Indigenous Species ◽  
Yellowstone Lake ◽  
The Impact

Yellowstone National Park (YNP) is a treasured national resource and an important element of tourism and the recreational economy in Wyoming. Because of its unique geological features and abundant wildlife and fisheries, YNP is a tourist destination for millions of people annually. Although this national symbol is cherished for its pristine condition and has been protected from most human influence for over 100 years, human mediated invasions of non­ indigenous species, such as several species of plants and animals, including an exotic snail (Potamopyrgus antipodarum), may alter this ecosystem. Recently an unauthorized introduction of lake trout (Salvelinus namaycush) to Yellowstone Lake was documented. Recent investigation at the University of Wyoming, indicated that in-lake predation by lake trout on juvenile and sub-adult native Yellowstone cutthroat trout (Oncorhyncus clarki bouvieri) could negatively influence recruitment of cutthroat trout (Stapp and Hayward 2002). This may lead to significant reductions in numbers of spawning adult cutthroat if current management actions are ineffective, or if they are not continuously pursued (Stapp and Hayward 2002). While lake trout invasion in Yellowstone Lake will likely have detrimental effects on in-lake communities and processes, reductions in populations of native cutthroat trout can potentially impact other aquatic and terrestrial ecosystems outside of Yellowstone Lake. Cutthroat trout in Yellowstone Lake annually migrate into tributary streams and rivers to spawn (Varley and Gresswell 1988), with runs up to 60,000 trout per season into small streams such as Clear Creek (Gresswell and Varley 1988). This spawning migration may significantly affect in­ stream communities (cf. Power 1990) and alter nutrient cycling within tributary streams (Peterson et al. 1993) and in the adjacent riparian forests (Ben­David et al. 1998; Hilderbrand et al. 1999). Therefore, spawning cutthroat trout not only have trophic effects on their ecosystem but also act as "ecosystem engineers" (i.e., species that influence structure and function of ecosystems through non­ trophic processes) because of their role in transporting large amounts of nutrients between ecosystems (Jones et al. 1994). Reductions in spawning adult cutthroat trout will likely alter in­stream processes. In addition, for piscivorous (fish­eating) predators, a significant decline in the number of adult spawning cutthroat trout may reduce recruitment and survival, and it could threaten viability of predator populations. In this project we are investigating the role of cutthroat trout in structuring stream ecosystems, their importance to a representative fish-predator - the river otter (Lontra canadensis), and possible effectson terrestrial plants through nutrient transport by otters to latrine sites (Ben-David et al. 1998 Hilderbrand et al. 1999). We hypothesize that the spawning migration of cutthroat trout will result in transport of nutrients from lake to streams, and from streams to terrestrial forests, through the activity of piscivorous predators. Because nitrogen (N) limits production in area streams (J. L. Tank and R 0. Hall unpublished data) and terrestrial ecosystems (Nadelhoffer et al. 1995) we focus our investigation of nutrient cycling on this element. These observations will enable us to predict how streams, trout predators, and the terrestrial landscape will be affected following cutthroat trout decline.

Biological processes in modelling soil functions – a balancing act between too complex and too simple

2021 ◽  
Author(s):  
Sara König ◽  
Ulrich Weller ◽  
Thomas Reitz ◽  
Bibiana Betancur-Corredor ◽  
Birgit Lang ◽  
...  
Keyword(s):  
Nutrient Cycling ◽  
Microbial Activity ◽  
Community Dynamics ◽  
Spatial Scales ◽  
Simulation Models ◽  
Microbial Processes ◽  
Biological Processes ◽  
Soil Functions ◽  
Management Options ◽  
The Impact

<p>Mechanistic simulation models are an essential tool for predicting soil functions such as nutrient cycling, water filtering and storage, productivity and carbon storage as well as the complex interactions between these functions. Most soil functions are driven or affected by soil organisms. Yet, biological processes are often neglected in soil function models or implicitly described by rate parameters. This can be explained by the high complexity of the soil ecosystem with its dynamic and heterogeneous environment, and by the range of temporal and spatial scales these processes are taking place at. On the other hand, the technical capabilities to explore microbial activity and communities in soil has greatly improved, resulting in new possibilities to understand soil microbial processes on various scales.</p><p>However, to integrate such biological processes in soil modelling, we need to find the right level of detail. Here, we present a systemic soil model approach to simulate the impact of different management options and changing climate on soil functions integrating biological activity on the profile scale. We use stoichiometric considerations to simulate microbial processes involved in different soil functions without explicitly describing community dynamics or functional groups. With this approach we are able to mechanistically describe microbial activity and its impact on the turnover of organic matter and nutrient cycling as driven by agricultural soil management.</p><p>Further, we discuss general challenges and ongoing developments to additionally consider, e.g., microbe-fauna-interactions or microbial feedback with soil structure dynamics.</p>

Do elephants influence the organisation and function of a South African grassland?

2009 ◽  
Vol 31 (4) ◽  
pp. 395 ◽  
Author(s):  
D. M. Parker ◽  
R. T. F. Bernard ◽  
J. Adendorff
Keyword(s):  
Nutrient Cycling ◽  
Function Analysis ◽  
Bare Soil ◽  
Grazing Pressure ◽  
Plant Litter ◽  
Occupation Time ◽  
Eastern Cape ◽  
Litter Accumulation ◽  
And Function ◽  
The Impact

The impact of elephants (Loxodonta africana) on woody plants is well known. Elephants can be regarded as drivers of ecosystem functioning by, for example, decreasing woody plant litter accumulation through defoliation. However, their influence within grassland landscapes is, by comparison, very poorly understood. We assessed the influence of elephants on grassland functionality at three separate sites (1, high elephant density, long occupation time; 2, low elephant density, short occupation time; 3, no elephants) in the Addo Elephant National Park, Eastern Cape Province, South Africa. Using landscape function analysis (LFA) we described the landscape organisation of each site, and, using visual surrogates, calculated indices of landscape stability, infiltration and nutrient cycling. The number of vegetation patches/10 m of transects surveyed was higher at sites where elephant density was high (3 elephants/km2) and where elephants had been present for a long time (>70 years). However, patch size was significantly smaller when elephant density/time of occupation increased, and the proportion of bare soil was higher where elephant density and occupation time were highest. In addition, stability, infiltration and nutrient cycling indices at a site scale were significantly lower where elephants were present at high densities and after a long occupation time. However, bare soil stability was not greatly affected by elephant grazing pressure, implying that a ‘threshold of potential concern’ has not yet arisen. We conclude that the functioning of this grassland landscape is significantly altered when elephants are present. These conclusions highlight the importance of management factors such as containment and the provision of artificial water points which may be compromising the functionality of these landscapes. We recommend ongoing assessments to inform future management decisions.

scholarly journals Agricultural diversification promotes multiple ecosystem services without compromising yield

2020 ◽  
Vol 6 (45) ◽  
pp. eaba1715 ◽  
Author(s):  
Giovanni Tamburini ◽  
Riccardo Bommarco ◽  
Thomas Cherico Wanger ◽  
Claire Kremen ◽  
Marcel G. A. van der Heijden ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Nutrient Cycling ◽  
Soil Fertility ◽  
Pest Control ◽  
Crop Yields ◽  
Cropping Systems ◽  
Context Dependency ◽  
Water Regulation ◽  
Trade Offs ◽  
The Impact

Enhancing biodiversity in cropping systems is suggested to promote ecosystem services, thereby reducing dependency on agronomic inputs while maintaining high crop yields. We assess the impact of several diversification practices in cropping systems on above- and belowground biodiversity and ecosystem services by reviewing 98 meta-analyses and performing a second-order meta-analysis based on 5160 original studies comprising 41,946 comparisons between diversified and simplified practices. Overall, diversification enhances biodiversity, pollination, pest control, nutrient cycling, soil fertility, and water regulation without compromising crop yields. Practices targeting aboveground biodiversity boosted pest control and water regulation, while those targeting belowground biodiversity enhanced nutrient cycling, soil fertility, and water regulation. Most often, diversification practices resulted in win-win support of services and crop yields. Variability in responses and occurrence of trade-offs highlight the context dependency of outcomes. Widespread adoption of diversification practices shows promise to contribute to biodiversity conservation and food security from local to global scales.

Soil organisms and sustainable productivity

Soil Research ◽  
1992 ◽  
Vol 30 (6) ◽  
pp. 855 ◽  
Author(s):  
KE Lee ◽  
CE Pankhurst
Keyword(s):  
Nutrient Cycling ◽  
Life Forms ◽  
Soil Microflora ◽  
Soil Biota ◽  
Soil Organisms ◽  
Soil Organism ◽  
The Impact ◽  
Sustainable Productivity

The soil is a habitat for a vast, complex and interactive community of soil organisms whose activities largely determine the chemical and physical properties of the soil. In a fertile soil the soil biota may have a biomass exceeding 20 t ha-1, with life forms ranging from microscopic bacteria to the largest of earthworms which may be 1 m in length. Only a small fraction, probably <20%, of the soil microflora and microfauna (including bacteria, fungi, algae, protozoa, nematodes, collembola, acari) have been described. The role of soil organisms in the development and maintenance of soil structure, in nutrient cycling and in their various interactions (including associative, harmful and beneficial) with plant roots is described. Trophic interactions between soil organism groups in developed agroecosystems are considered in relation to nutrient cycling and the impact such interactions have on populations of saprophytic, parasitic and symbiotic microorganisms. Prospects for the management of the soil biota to promote sustainable productivity are illustrated by describing the effects of tillage on the composition of soil organism communities. Management technologies that conserve the biodiversity of communities may provide the greatest benefits for the long term sustainability of the soil resource.

The restoration of a shallow lake by introducing Potamogeton spp.: The impact of waterfowl grazing

2003 ◽  
Vol 8 (3-4) ◽  
pp. 177-187 ◽  
Author(s):  
Torben L. Lauridsen ◽  
Hakan Sandsten ◽  
Poul Hald Moller
Keyword(s):  
Shallow Lake ◽  
The Impact
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