Temporal dynamics of soil spatial heterogeneity in sagebrush-wheatgrass steppe during a growing season

1996 ◽  
Vol 184 (2) ◽  
pp. 299-309 ◽  
Author(s):  
R. J. Ryel ◽  
M. M. Caldwell ◽  
J. H. Manwaring
Keyword(s):  
Spatial Heterogeneity ◽  
Temporal Dynamics ◽  
Growing Season ◽  
Soil Spatial Heterogeneity

Soil Spatial Heterogeneity and Systems of Agriculture

2015 ◽  
Vol 2 (1) ◽  
pp. 50-59
Author(s):  
V. Medvedev
Keyword(s):  
Spatial Heterogeneity ◽  
Soil Cover ◽  
Regular Grid ◽  
Resource Saving ◽  
The Third ◽  
Soil Spatial Heterogeneity ◽  
Agriculture Systems ◽  
Zonal Soils

Aim. To consider soil continuality and discreteness as features of heterogeneity manifestation in a soil cover, important for construction of agriculture systems. Methods. Geostatistical research of soil spatial heterogeneity, revealing the contours of a fi eld with various parameters of fertility. Results. The use of principles of precise agriculture and inspection of indicative properties of fi eld soils using a regular grid allowed to divide a fi eld into contours with three levels of fertility: the fi rst one is characterized by optimal or close to optimum properties which allows refusing from (or reducing substantially) tillage, introduction of fertilizers or chemical ameliorates; the second one has average parameters of fertility corresponding to zonal soils and demands the application of zonal technologies; the third one (with the worst parameters of fertility) presupposes regular use of the improved technologies. Conclusions. The introduction of precise agriculture will allow replacing a traditional zonal system with thenew which is soil-protecting and resource-saving one.

scholarly journals Life on leaves : uncovering temporal dynamics in Arabidopsis' leaf microbiota

2021 ◽  
Author(s):  
Juliana Almario ◽  
Maryam Mahmoudi ◽  
Samuel Kroll ◽  
Matthew Agler ◽  
Aleksandra Placzek ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Photosynthetic Activity ◽  
Temporal Dynamics ◽  
Growing Season ◽  
High Turnover ◽  
Microbial Network ◽  
Stabilization Phase ◽  
Time Patterns ◽  
Microbe Interactions ◽  
Compositional Changes

Leaves are primarily responsible for the plant′s photosynthetic activity. Thus, changes in the phyllosphere microbiota, which includes deleterious and beneficial microbes, can have far reaching effects on plant fitness and productivity. In this context, identifying the processes and microorganisms that drive the changes in the leaf microbiota over a plant′s lifetime is crucial. In this study we analyzed the temporal dynamics in the leaf microbiota of Arabidopsis thaliana, integrating both compositional changes and changes in microbe-microbe interactions via the study of microbial networks. Field-grown Arabidopsis were used to follow leaf bacterial, fungal and oomycete communities, throughout the plant′s growing season (extending from November to March), over three consecutive years. Our results revealed the existence of conserved time patterns, with microbial communities and networks going through a stabilization phase (decreasing diversity and variability) at the beginning of the plant′s growing season. Despite a high turnover in these communities, we identified 19 "core" taxa persisting in Arabidopsis leaves across time and plant generations. With the hypothesis these microbes could be playing key roles in the structuring of leaf microbial communities, we conducted a time-informed microbial network analysis which showed core taxa are not necessarily highly connected network "hubs" and "hubs" alternate with time. Our study shows that leaf microbial communities exhibit reproducible dynamics and patterns, suggesting it could be possible to predict and drive these microbial communities to desired states.

Temporal dynamics and spatial heterogeneity of microalgal biomass in recently reclaimed intertidal flats of the Saemangeum area, Korea

2016 ◽  
Vol 116 ◽  
pp. 1-11 ◽  
Author(s):  
Bong-Oh Kwon ◽  
Yeonjung Lee ◽  
Jinsoon Park ◽  
Jongseong Ryu ◽  
Seongjin Hong ◽  
...  
Keyword(s):  
Spatial Heterogeneity ◽  
Temporal Dynamics ◽  
Microalgal Biomass ◽  
Intertidal Flats

scholarly journals Temporal dynamics of nonstructural carbohydrates and xylem growth in Pinus sylvestris exposed to drought

2011 ◽  
Vol 41 (8) ◽  
pp. 1590-1597 ◽  
Author(s):  
Walter Oberhuber ◽  
Irene Swidrak ◽  
Daniela Pirkebner ◽  
Andreas Gruber
Keyword(s):  
Pinus Sylvestris ◽  
Temporal Dynamics ◽  
Growing Season ◽  
Cambial Activity ◽  
Wood Formation ◽  
Nonstructural Carbohydrates ◽  
Late Wood ◽  
Structural Growth ◽  
Xylem Growth ◽  
Soil Dryness

Wood formation requires a continuous supply of carbohydrates for structural growth and metabolism. In the montane belt of the central Austrian Alps, we monitored the temporal dynamics of xylem growth and nonstructural carbohydrates (NSC) in stem sapwood of Scots pine ( Pinus sylvestris L.) during the growing season of 2009, which was characterized by exceptional soil dryness within the study area. Soil water content dropped below 10% at the time of maximum xylem growth at the end of May. Histological analyses have been used to describe cambial activity and xylem growth. Determination of NSC was performed using specific enzymatic assays revealing that total NSC ranged from 0.8% to 1.7% dry matter throughout the year. Significant variations (P < 0.05) of the size of the NSC pool were observed during the growing season. Starch showed persistent abundance throughout the year, reaching a maximum shortly before onset of late wood formation in mid-July. Seasonal dynamics of NSC and xylem growth suggest that (i) high sink activity occurred at the start of the growing season in spring and during late wood formation in summer and (ii) there was no particular shortage in NSC, which caused P. sylvestris to draw upon stem reserves more heavily during the drought in 2009.

scholarly journals Spatial Heterogeneity of the Temporal Dynamics of Arctic Tundra Vegetation

2018 ◽  
Vol 45 (17) ◽  
pp. 9206-9215 ◽  
Author(s):  
L. M. Reichle ◽  
H. E. Epstein ◽  
U. S. Bhatt ◽  
M. K. Raynolds ◽  
D. A. Walker
Keyword(s):  
Spatial Heterogeneity ◽  
Temporal Dynamics ◽  
Arctic Tundra ◽  
Tundra Vegetation

scholarly journals Effects of Spatial Variability and Relic DNA Removal on the Detection of Temporal Dynamics in Soil Microbial Communities

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Paul Carini ◽  
Manuel Delgado-Baquerizo ◽  
Eve-Lyn S. Hinckley ◽  
Hannah Holland‐Moritz ◽  
Tess E. Brewer ◽  
...  
Keyword(s):  
Microbial Community ◽  
Spatial Variability ◽  
Spatial Heterogeneity ◽  
Microbial Communities ◽  
Temporal Variability ◽  
Temporal Dynamics ◽  
Microbial Community Composition ◽  
Soil Microbial Communities ◽  
Environmental Preferences ◽  
Soil Microbial

ABSTRACT Few studies have comprehensively investigated the temporal variability in soil microbial communities despite widespread recognition that the belowground environment is dynamic. In part, this stems from the challenges associated with the high degree of spatial heterogeneity in soil microbial communities and because the presence of relic DNA (DNA from dead cells or secreted extracellular DNA) may dampen temporal signals. Here, we disentangle the relationships among spatial, temporal, and relic DNA effects on prokaryotic and fungal communities in soils collected from contrasting hillslopes in Colorado, USA. We intensively sampled plots on each hillslope over 6 months to discriminate between temporal variability, intraplot spatial heterogeneity, and relic DNA effects on the soil prokaryotic and fungal communities. We show that the intraplot spatial variability in microbial community composition was strong and independent of relic DNA effects and that these spatial patterns persisted throughout the study. When controlling for intraplot spatial variability, we identified significant temporal variability in both plots over the 6-month study. These microbial communities were more dissimilar over time after relic DNA was removed, suggesting that relic DNA hinders the detection of important temporal dynamics in belowground microbial communities. We identified microbial taxa that exhibited shared temporal responses and show that these responses were often predictable from temporal changes in soil conditions. Our findings highlight approaches that can be used to better characterize temporal shifts in soil microbial communities, information that is critical for predicting the environmental preferences of individual soil microbial taxa and identifying linkages between soil microbial community composition and belowground processes. IMPORTANCE Nearly all microbial communities are dynamic in time. Understanding how temporal dynamics in microbial community structure affect soil biogeochemistry and fertility are key to being able to predict the responses of the soil microbiome to environmental perturbations. Here, we explain the effects of soil spatial structure and relic DNA on the determination of microbial community fluctuations over time. We found that intensive spatial sampling was required to identify temporal effects in microbial communities because of the high degree of spatial heterogeneity in soil and that DNA from nonliving sources masks important temporal patterns. We identified groups of microbes with shared temporal responses and show that these patterns were predictable from changes in soil characteristics. These results provide insight into the environmental preferences and temporal relationships between individual microbial taxa and highlight the importance of considering relic DNA when trying to detect temporal dynamics in belowground communities.

DIFFUSION-DRIVEN INSTABILITIES AND SPATIO-TEMPORAL PATTERNS IN AN AQUATIC PREDATOR–PREY SYSTEM WITH BEDDINGTON–DEANGELIS TYPE FUNCTIONAL RESPONSE

2011 ◽  
Vol 21 (03) ◽  
pp. 663-684 ◽  
Author(s):  
RANJIT KUMAR UPADHYAY ◽  
N. K. THAKUR ◽  
V. RAI
Keyword(s):  
Pattern Formation ◽  
Spatial Heterogeneity ◽  
Collective Motion ◽  
Temporal Dynamics ◽  
Fish Predation ◽  
Building Blocks ◽  
Aquatic System ◽  
Predator Species ◽  
Predator Prey ◽  
Spatio Temporal

Predator–prey communities are building blocks of an ecosystem. Feeding rates reflect interference between predators in several situations, e.g. when predators form a dense colony or perform collective motion in a school, encounter prey in a region of limited size, etc. We perform spatio-temporal dynamics and pattern formation in a model aquatic system in both homogeneous and heterogeneous environments. Zooplanktons are predated by fishes and interfere with individuals of their own community. Numerical simulations are carried out to explore Turing and non-Turing spatial patterns. We also examine the effect of spatial heterogeneity on the spatio-temporal dynamics of the phytoplankton–zooplankton system. The phytoplankton specific growth rate is assumed to be a linear function of the depth of the water body. It is found that the spatio-temporal dynamics of an aquatic system is governed by three important factors: (i) intensity of interference between the zooplankton, (ii) rate of fish predation and (iii) the spatial heterogeneity. In an homogeneous environment, the temporal dynamics of prey and predator species are drastically different. While prey species density evolves chaotically, predator densities execute a regular motion irrespective of the intensity of fish predation. When the spatial heterogeneity is included, the two species oscillate in unison. It has been found that the instability observed in the model aquatic system is diffusion driven and fish predation acts as a regularizing factor. We also observed that spatial heterogeneity stabilizes the system. The idea contained in the paper provides a better understanding of the pattern formation in aquatic systems.

How do meteorological variables and topography control species-specific water uptake strategy along a forested hillslope?

2020 ◽  
Author(s):  
Ginevra Fabiani ◽  
Daniele Penna ◽  
Julian Klaus
Keyword(s):  
Isotopic Composition ◽  
Soil Water ◽  
Water Uptake ◽  
Temporal Dynamics ◽  
Growth Parameters ◽  
Stream Water ◽  
Growing Season ◽  
Grab Sampling ◽  
Spatio Temporal ◽  
Species Specific

&lt;p&gt;In the face of current global warming conditions, temperate forest ecosystems are expected to be strongly affected by temperature increase and more frequent and intense water shortage. This leads to severe stress for forest vegetation in many temperate systems. Therefore, understanding the vegetation water use in temperate forests is urgently needed for more effective forest management strategies. Root water uptake (RWU) is a species-specific trait (tree physiology and root architecture) and its spatio-temporal patterns are controlled by a range of site-specific (e.g., topography, geology, pedology) and meteorological factors (e.g., temperature, soil humidity, rainfall.&lt;/p&gt;&lt;p&gt;In the present study, we use stable water isotopologues as ecohydrological tracers combined with continuous measurement of hydrometeorological (weather variables, groundwater levels, soil moisture, streamflow) and physiological (sap flow, radial stem growth) parameters to investigate the spatio-temporal dynamics of water uptake for beech (Fagus sylvatica L.) and sessile oak (Quercus petraea (Matt.) Liebl) trees along a hillslope in a Luxemburgish catchment.&lt;/p&gt;&lt;p&gt;Fortnightly field campaigns were carried out during the growing season (April-October) 2019 to sample water from xylem, soil water at different depths, groundwater, stream water, and precipitation. Soil water isotopic composition and xylem water were extracted via cryogenic distillation. Grab sampling was performed for the other water pools. The isotopic composition was determined through laser spectroscopy and mass spectrometry (for xylem samples only).&lt;/p&gt;&lt;p&gt;From preliminary results, the isotopic composition of xylem water shows a marked seasonal variability suggesting a plasticity in RWU or a change in the isotopic composition of the water pools over the growing season. Moreover, beech and oak trees exhibit different uptake strategies when water supply is low. Within the range of observed groundwater variation topography does not play a statistically significant role on RWU.&lt;/p&gt;

Effects of land-use history on soil spatial heterogeneity of macro- and trace elements in the Southern Piedmont USA

Geoderma ◽  
2010 ◽  
Vol 156 (1-2) ◽  
pp. 60-73 ◽  
Author(s):  
Jianwei Li ◽  
Daniel deB. Richter ◽  
Arlene Mendoza ◽  
Paul Heine
Keyword(s):  
Land Use ◽  
Trace Elements ◽  
Spatial Heterogeneity ◽  
Land Use History ◽  
Soil Spatial Heterogeneity ◽  
Effects Of Land Use

scholarly journals Spatial heterogeneity and temporal dynamics of mosquito population density and community structure in Hainan Island, China

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Yiji Li ◽  
Guofa Zhou ◽  
Saifeng Zhong ◽  
Xiaoming Wang ◽  
Daibin Zhong ◽  
...  
Keyword(s):  
Community Structure ◽  
Population Density ◽  
Spatial Heterogeneity ◽  
Temporal Dynamics ◽  
Hainan Island ◽  
Mosquito Population
Sign in / Sign up

Export Citation Format

Share Document