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

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

Greenness trends of Arctic tundra vegetation in the 1990s: comparison of two NDVI data sets from NOAA AVHRR systems

2007 ◽  
Vol 28 (21) ◽  
pp. 4807-4822 ◽  
Author(s):  
D. Stow ◽  
A. Petersen ◽  
A. Hope ◽  
R. Engstrom ◽  
L. Coulter
Keyword(s):  
Arctic Tundra ◽  
Data Sets ◽  
Noaa Avhrr ◽  
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.

scholarly journals A Phenological Approach to Spectral Differentiation of Low-Arctic Tundra Vegetation Communities, North Slope, Alaska

2017 ◽  
Vol 9 (11) ◽  
pp. 1200 ◽  
Author(s):  
Alison Beamish ◽  
Nicholas Coops ◽  
Sabine Chabrillat ◽  
Birgit Heim
Keyword(s):  
Arctic Tundra ◽  
North Slope ◽  
Vegetation Communities ◽  
Tundra Vegetation ◽  
Low Arctic

Reflectance characteristics of arctic tundra vegetation from airborne radiometry

1993 ◽  
Vol 14 (6) ◽  
pp. 1239-1244 ◽  
Author(s):  
D. A. STOW ◽  
A. S. HOPE ◽  
T. H. GEORGE
Keyword(s):  
Arctic Tundra ◽  
Tundra Vegetation

scholarly journals Arctic Tundra Vegetation Functional Types Based on Photosynthetic Physiology and Optical Properties

2013 ◽  
Vol 6 (2) ◽  
pp. 265-275 ◽  
Author(s):  
Karl Fred Huemmrich ◽  
John A. Gamon ◽  
Craig E. Tweedie ◽  
Petya K. Entcheva Campbell ◽  
David R. Landis ◽  
...  
Keyword(s):  
Optical Properties ◽  
Arctic Tundra ◽  
Photosynthetic Physiology ◽  
Functional Types ◽  
Tundra Vegetation
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