scholarly journals Spatio-temporal permanence and plasticity of foraging trails in young and mature leaf-cutting ant colonies (Atta spp.)

2005 ◽  
Vol 21 (6) ◽  
pp. 677-688 ◽  
Author(s):  
Christian Kost ◽  
Evandro Gama de Oliveira ◽  
Tobias Aurelius Knoch ◽  
Rainer Wirth
Keyword(s):  
Host Plants ◽  
Life Stage ◽  
Temporal Distribution ◽  
Life Forms ◽  
Ant Colonies ◽  
General Hypothesis ◽  
Leaf Cutting ◽  
Spatio Temporal ◽  
Foraging Pattern

The distribution and formation of foraging trails have largely been neglected as factors explaining harvesting patterns of leaf-cutting ants. We applied fractal analysis, circular, and conventional statistics to published and newly recorded trail maps of seven Atta colonies focusing on three aspects: permanence, spatio-temporal plasticity and colony life stage. In the long term, trail patterns of young and mature Atta colonies revealed that foraging activities were focused on distinct, static sectors that made up only parts of their potentially available foraging range. Within these foraging sectors, trails were typically ephemeral and highly variable in space and time. These ephemeral trails were concentrated around permanent trunk trails in mature and around nest entrances in young colonies. Besides these similarities, the comparison of trail systems between the two life stages indicated that young colonies exploited fewer leaf sources, used smaller and less-complex systems of foraging trails, preferred different life forms as host plants, and switched hosts more often compared with mature colonies. Based on these analyses, we propose a general hypothesis which describes the foraging pattern in Atta as a result of initial foraging experiences, spatio-temporal distribution of suitable host plants, energetic constraints, and other factors such as seasonality and interspecific predation.

scholarly journals CONSTRUCTION AND ANALYSIS OF LONG-TERM SURFACE TEMPERATURE DATASET IN FUJIAN PROVINCE

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 1223-1227 ◽  
Author(s):  
W. E. Li ◽  
X. Q. Wang ◽  
H. Su
Keyword(s):  
Time Series ◽  
Surface Temperature ◽  
Land Surface ◽  
Rapid Development ◽  
Temporal Distribution ◽  
Heat Fluxes ◽  
Urban Region ◽  
Fujian Province ◽  
Spatio Temporal

Land surface temperature (LST) is a key parameter of land surface physical processes on global and regional scales, linking the heat fluxes and interactions between the ground and atmosphere. Based on MODIS 8-day LST products (MOD11A2) from the split-window algorithms, we constructed and obtained the monthly and annual LST dataset of Fujian Province from 2000 to 2015. Then, we analyzed the monthly and yearly time series LST data and further investigated the LST distribution and its evolution features. The average LST of Fujian Province reached the highest in July, while the lowest in January. The monthly and annual LST time series present a significantly periodic features (annual and interannual) from 2000 to 2015. The spatial distribution showed that the LST in North and West was lower than South and East in Fujian Province. With the rapid development and urbanization of the coastal area in Fujian Province, the LST in coastal urban region was significantly higher than that in mountainous rural region. The LST distributions might affected by the climate, topography and land cover types. The spatio-temporal distribution characteristics of LST could provide good references for the agricultural layout and environment monitoring in Fujian Province.

scholarly journals Assessing the Spatial and Spatio-Temporal Distribution of Forest Species via Bayesian Hierarchical Modeling

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 573 ◽  
Author(s):  
Óscar Rodríguez de Rivera ◽  
Antonio López-Quílez ◽  
Marta Blangiardo
Keyword(s):  
Hierarchical Modeling ◽  
Temporal Distribution ◽  
Short Term ◽  
Distribution Models ◽  
Address Climate Change ◽  
Bayesian Hierarchical ◽  
Temporal Models ◽  
Spatio Temporal ◽  
The Relationship

Climatic change is expected to affect forest development in the short term, as well as the spatial distribution of species in the long term. Species distribution models are potentially useful tools for guiding species choices in reforestation and forest management prescriptions to address climate change. The aim of this study is to build spatial and spatio-temporal models to predict the distribution of four different species present in the Spanish Forest Inventory. We have compared the different models and showed how accounting for dependencies in space and time affect the relationship between species and environmental variables.

Analysis of methodological and physical bias on borehole temperature reconstructions from a pseudo-proxy approach.

2020 ◽  
Author(s):  
Camilo Melo Aguilar ◽  
Fidel González Rouco ◽  
Elena García Bustamante ◽  
Norman Steinert ◽  
Jorge Navarro ◽  
...  
Keyword(s):  
Grid Point ◽  
Ground Surface ◽  
Temporal Distribution ◽  
Surface Air Temperature ◽  
Internal Variability ◽  
Last Millennium ◽  
Subsurface Temperature ◽  
Borehole Logs ◽  
Spatio Temporal

<p>The analysis of subsurface temperature measurements from boreholes is a well established approach for reconstructing last millennium (LM) surface air temperature (SAT). It is based on the assumption that SAT variations are strongly coupled to ground surface temperature (GST) variations and transferred to the subsurface by thermal conduction. We have evaluated the long-term SAT-GST coupling over the LM using an ensemble of both full- and single-forcing simulations form the Community Earth System Model-Last Millennium Ensemble (CESM-LME). Such a premise is explored by investigating the evolution of the long-term SAT–GST relationship. The results indicate that SAT–GST coupling is strong at global and above multi-decadal timescales in CESM-LME. However, at local to regional scales this relationship experiences considerable long-term changes mostly after the end of the 19th century. Land use land cover (LULC) changes stand as the main driver for locally and regionally decoupling SAT and GST, due to the changes in the energy fluxes at the surface. Snow cover feedbacks due to the influence of GHG forcing are also important for corrupting the long-term SAT–GST coupling. These processes may represent a source of bias for SAT reconstructions from GST borehole profiles. In light of these findings, we subsequently assessed the potential effects on SAT reconstructions from the borehole method in pseudo-proxy experiments that make use of the same set of simulations from the CESM-LME. First, a heat-conduction forward model has been used to estimate subsurface temperature-anomaly profiles using simulated GST as boundary conditions. Subsequently, singular value decomposition inversion (SVD) has been applied to reconstruct LM GST variations from the simulated profiles. We implemented and ideal scenario in which it is assumed the existence of borehole logs at every model grid point. Further, this scenario considers that all boreholes are logged homogenously at the same time. In addition, we implemented a more realistic approach in which the real-world spatio-temporal distribution of the global borehole network is considered. Results show that the SVD inversion is able to retrieve the long-term GST variations over the LM when an appropriated coverture of borehole logs is available. However, due to the limited spatio-temporal distribution of the actual borehole network, there is a lost in the accuracy to retrieve the simulated GST 20th century trends, with the temporal logging of the BTPs as the main sampling issue. Furthermore, in the surrogate reality of the CESM-LME the SAT-GST decoupling, due to the influence of LULC and GHG forcings, leads to a slightly underestimation of SAT warming during the industrial period across the CESM-LME. The level of impact is, however, highly depended on the realization of internal variability.</p>

scholarly journals Spatial and temporal escape from fungal parasitism in natural communities of anciently asexual bdelloid rotifers

2013 ◽  
Vol 280 (1765) ◽  
pp. 20131255 ◽  
Author(s):  
Christopher G. Wilson ◽  
Paul W. Sherman
Keyword(s):  
Field Experiments ◽  
Life Stage ◽  
Red Queen Hypothesis ◽  
Bdelloid Rotifers ◽  
Antagonistic Coevolution ◽  
Freshwater Habitats ◽  
Spatio Temporal ◽  
The Red Queen ◽  
Natural Communities

Sexual reproduction is costly, but it is nearly ubiquitous among plants and animals, whereas obligately asexual taxa are rare and almost always short-lived. The Red Queen hypothesis proposes that sex overcomes its costs by enabling organisms to keep pace with coevolving parasites and pathogens. If so, the few cases of stable long-term asexuality ought to be found in groups whose coevolutionary interactions with parasites are unusually weak. In theory, antagonistic coevolution will be attenuated if hosts disperse among patches within a metapopulation separately from parasites and more rapidly. We examined whether these conditions are met in natural communities of bdelloid rotifers, one of the longest-lived asexual lineages. At any life stage, these microscopic invertebrates can tolerate the complete desiccation of their ephemeral freshwater habitats, surviving as dormant propagules that are readily carried by the wind. In our field experiments, desiccation and wind transport enabled bdelloids to disperse independently of multiple fungal parasites, in both time and space. Surveys of bdelloid communities in unmanipulated moss patches confirmed that fungal parasitism was negatively correlated with extended drought and increasing height (exposure to wind). Bdelloid ecology therefore matches a key condition of models in which asexuals persist through spatio-temporal decoupling from coevolving enemies.

scholarly journals Spatio-temporal distribution of eggs and larvae of half-fin anchovy Setipinna taty (Valenciennes, 1848) in the inshore waters off Jiangsu, China

2019 ◽  
Vol 66 (1) ◽  
Author(s):  
Yan Jin ◽  
Zun-Lei Liu ◽  
Jian-Hua Tang ◽  
Yong Liu
Keyword(s):  
Fishery Management ◽  
Life Stage ◽  
Temporal Distribution ◽  
Early Life Stage ◽  
Additive Models ◽  
Significant Shift ◽  
Larvae And Juveniles ◽  
Inshore Waters ◽  
Spatio Temporal ◽  
Eggs And Larvae

Understanding the spatial distribution and environmental characteristics of fish spawning grounds is essential to design effective fishery management. The half-fin anchovy Setipinna taty (Valenciennes, 1848) plays an important role in the marine food web. A survey with 54 stations was conducted in 2014 to study the spatio-temporal distribution of eggs and larvae of half-fin anchovy around the inshore waters of Jiangsu, China. Half-fin anchovy eggs, larvae and juveniles were collected every month from April to July 2014. Generalised additive models were used to investigate the relationship between distribution of eggs, larvae and juveniles and environmental variables. A total of 4150 eggs and 685 half-fin anchovy larvae and juveniles were caught during the survey. During the spawning season, the highest egg densities were located in the inshore water area (121°-122°E, 32.5-33.5°N), with no significant shift in location of egg densities through time. The distribution of larvae and juveniles mostly overlapped with the egg distribution, suggesting that the early life stage of half-fin anchovy are distributed within the inshore waters of Jiangsu. The optimal water temperature, salinity and depth for eggs and larvae were in the range of 14.0-24.6°C, 28.7-29.8 ‰ and 15.9-17.4 m, respectively.

scholarly journals Spatio-Temporal Distribution of Landslides in Java and the Triggering Factors

2017 ◽  
Vol 31 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Danang Sri Hadmoko ◽  
Franck Lavigne ◽  
Junun Sartohadi ◽  
Christopher Gomez ◽  
D Daryono
Keyword(s):  
Temporal Distribution ◽  
Rainfall Threshold ◽  
Short Term ◽  
Rainfall Events ◽  
Landslide Occurrence ◽  
Central Java ◽  
Causative Factors ◽  
Spatio Temporal ◽  
Gis Environment

Java Island, the most populated island of Indonesia, is prone to landslide disasters. Their occurrence and impact have increased mainly as the result of natural factors, aggravated by human imprint. This paper is intended to analyse: (1) the spatio-temporal variation of landslides in Java during short term and long-term periods, and (2) their causative factors such as rainfall, topography, geology, earthquakes, and land-use. The evaluation spatially and temporally of historical landslides and consequences were based on the landslide database covering the period of 1981 – 2007 in the GIS environment. Database showed that landslides distributed unevenly between West Java (67 %), Central Java (29 %) and East Java (4 %). Slope failures were most abundant on the very intensively weathered zone of old volcanic materials on slope angles of 30O – 40O. Rainfall threshold analysis showed that shallow landslides and deep-seated landslides were triggered by rainfall events of 300 – 600 mm and > 600 mm respectively of antecedent rainfall during 30 consecutive days, and many cases showed that the landslides were not always initiated by intense rainfall during the landslide day. Human interference plays an important role in landslide occurrence through land conversion from natural forest to dryland agriculture which was the host of most of landslides in Java. These results and methods can be used as valuable information on the spatio-temporal characteristics of landslides in Java and their relationship with causative factors, thereby providing a sound basis for landslide investigation in more detail.

scholarly journals Plankton in waters adjacent to the Laje de Santos state marine conservation park, Brazil: spatio-temporal distribution surveys

2017 ◽  
Vol 65 (4) ◽  
pp. 564-575 ◽  
Author(s):  
Marília Bueno ◽  
Samantha Fernandes Alberto ◽  
Renan de Carvalho ◽  
Tânia Marcia Costa ◽  
Áurea Maria Ciotti ◽  
...  
Keyword(s):  
Temporal Distribution ◽  
Taxonomic Composition ◽  
Marine Conservation ◽  
Zooplankton Biomass ◽  
Adjacent Area ◽  
Coastal Marine ◽  
Spatio Temporal ◽  
Term Monitoring

Abstract The coastal marine plankton plays a major role in ecosystem functioning by linking pelagic and benthonic environments through energy fluxes. Understanding the dynamic of planktonic organisms is also crucial for conservation and management purposes. Plankton was sampled at ten sites in the waters of the PEMLS and the adjacent area, on four different occasions through 2013 and 2015 in order to identify key planktonic groups and protocols for long-term monitoring. Ninety taxa of zooplanktonic organisms were found with holoplanktonic copepods and cladocerans dominating samples. Zooplankton biomass, mortality and taxonomic composition varied both in space and time. Surface chlorophyll-a concentrations varied spatio-temporally. A protocol for monitoring the plankton of the waters in and adjacent to the PEMLS is suggested based on biomass and mortality of zooplankton and biomass of phytoplankton using periodically in situ calibrated ocean color satellite imagery.

Effects of long-term fertilization modes on spatio-temporal distribution and accumulation of soil nitrate nitrogen in solar greenhouse

2011 ◽  
Vol 19 (2) ◽  
pp. 246-252
Author(s):  
He-Fa YANG ◽  
Ju-Fang FAN ◽  
Li-Na LIANG ◽  
Yu-Bao YANG ◽  
Ling-An NIU ◽  
...  
Keyword(s):  
Nitrate Nitrogen ◽  
Temporal Distribution ◽  
Soil Nitrate ◽  
Solar Greenhouse ◽  
Spatio Temporal

scholarly journals Meandering Evolution and Width Variation, a Physics-Statistical Based Modeling Approach

10.29007/qvdj ◽  
2018 ◽  
Author(s):  
Sergio Lopez Dubon ◽  
Daniele Pietro Viero ◽  
Stefano Lanzoni
Keyword(s):  
Temporal Distribution ◽  
Channel Width ◽  
Erosion And Deposition ◽  
River Bank ◽  
Term Evolution ◽  
Stress Threshold ◽  
Spatio Temporal ◽  
Deposition Processes ◽  
The Stability

Many models have been proposed to simulate and understand the long-term evolution of meandering rivers. These models analyze the hydraulics of the in-channel flow and the river bank movement (erosion – accretion) process in different ways, but some gap still remain, e.g. the stability of long-term simulations when width variations are accounted for. Here we proposed a physics-statistical based approach to simulate the river bank evolution, that erosion and deposition processes act independently, with a specific shear stress threshold for each of them. In addition, we link the width evolution with a parametric probability distribution (PPD) based on a mean characteristic channel width. We are thus able to obtaining stable long-term simulations with realistic and reasonable spatio-temporal distribution of the along channel width.

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