scholarly journals Long‐term sand dune spatio‐temporal dynamics and endemic plant habitat extent in the Athabasca sand dunes of northern Saskatchewan

2018 ◽  
Vol 5 (1) ◽  
pp. 70-86 ◽  
Author(s):  
Anjika U. Attanayake ◽  
Dandan Xu ◽  
Xulin Guo ◽  
Eric G. Lamb
Keyword(s):  
Sand Dune ◽  
Temporal Dynamics ◽  
Sand Dunes ◽  
Endemic Plant ◽  
Northern Saskatchewan ◽  
Spatio Temporal ◽  
Plant Habitat

scholarly journals Increasing frequency of low summer precipitation synchronizes dynamics and compromises metapopulation stability in the Glanville fritillary butterfly

2015 ◽  
Vol 282 (1806) ◽  
pp. 20150173 ◽  
Author(s):  
Ayco J. M. Tack ◽  
Tommi Mononen ◽  
Ilkka Hanski
Keyword(s):  
Population Dynamics ◽  
Population Change ◽  
Temporal Dynamics ◽  
Summer Precipitation ◽  
Life History Stage ◽  
General Effect ◽  
Spatial Synchrony ◽  
Glanville Fritillary Butterfly ◽  
Spatio Temporal

Climate change is known to shift species' geographical ranges, phenologies and abundances, but less is known about other population dynamic consequences. Here, we analyse spatio-temporal dynamics of the Glanville fritillary butterfly ( Melitaea cinxia ) in a network of 4000 dry meadows during 21 years. The results demonstrate two strong, related patterns: the amplitude of year-to-year fluctuations in the size of the metapopulation as a whole has increased, though there is no long-term trend in average abundance; and there is a highly significant increase in the level of spatial synchrony in population dynamics. The increased synchrony cannot be explained by increasing within-year spatial correlation in precipitation, the key environmental driver of population change, or in per capita growth rate. On the other hand, the frequency of drought during a critical life-history stage (early larval instars) has increased over the years, which is sufficient to explain the increasing amplitude and the expanding spatial synchrony in metapopulation dynamics. Increased spatial synchrony has the general effect of reducing long-term metapopulation viability even if there is no change in average metapopulation size. This study demonstrates how temporal changes in weather conditions can lead to striking changes in spatio-temporal population dynamics.

scholarly journals Modelling and  assessing driving factors of the spatial and temporal dynamics of the sand  dunes in the district of Errachidia, Morocco

2021 ◽  
Author(s):  
Tudal SINSIN ◽  
Fouad MOUNIR ◽  
Ahmed El ABOUDI
Keyword(s):  
Sand Dune ◽  
Temporal Dynamics ◽  
Moving Average ◽  
Sand Dunes ◽  
Ecological Factors ◽  
Temperature And Precipitation ◽  
Spatial And Temporal Dynamics ◽  
Combined Action ◽  
Landsat Satellite ◽  
Dune Dynamics

The desertification affects more than 250,000 ha in the district of Errachidia and results in the expansion of desert landscapes such as the Regs, Hamadas and the Dunes. The latter is a big concern in the district since it is the source of siltation, which threatens dwellings, cultivated lands and water bodies. It is of paramount importance to understand the causes and consequences of silting to develop strategies to combat it. Thus, first, we analysed the spatial and temporal dynamics of sand dunes until 2069 by applying the Seasonal Autoregressive Integrated Moving-Average (SARIMA) model on a time series of sand dune areas. These areas were calculated annually from 1987 to 2019 by computing the sand cover index (SCI) on Landsat satellite images. Furthermore, we evaluated the influence of different natural and human factors such as temperature, precipitation, wind, vegetation, and population growth, on sand dune dynamics using Spearman’s correlation test. The results indicated that the area of sand dunes will increase by 1.7% per year between 2019 and 2069 in the district of Errachidia. This increase would be mainly caused by the combined action of ecological factors, which vary from year to year. In general, temperature and precipitation act indirectly on wind and vegetation to influence the dynamics of sand dunes in hyper-arid areas where the soil is bare or poorly covered with vegetation, where precipitation is low and where temperature is high.

Assessing variation in assemblages of large marine fauna off ocean beaches using drones

2020 ◽  
Vol 71 (1) ◽  
pp. 68 ◽  
Author(s):  
Brendan P. Kelaher ◽  
Andrew P. Colefax ◽  
Alejandro Tagliafico ◽  
Melanie J. Bishop ◽  
Anna Giles ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Bottlenose Dolphins ◽  
Spatial And Temporal Variation ◽  
Marine Animals ◽  
Marine Fauna ◽  
South Wales ◽  
Carcharhinus Leucas ◽  
Spatio Temporal ◽  
Marine Wildlife

The turbulent waters off ocean beaches provide habitat for large marine fauna, including dolphins, sharks, rays, turtles and game fish. Although, historically, these assemblages have proven difficult to quantify, we used a new drone-based approach to assess spatial and temporal variation in assemblages of large marine fauna off four exposed beaches in New South Wales, Australia. In total, 4388 individual large marine animals were identified from 216 drone flights. The most common taxa, bottlenose dolphins (Tursiops spp.) and Australian cownose rays (Rhinoptera neglecta), occurred in 25.5 and 19.9% of flights respectively. White (Carcharodon carcharias), bull (Carcharhinus leucas) and other whaler (Carcharhinus spp.) sharks were observed in <1% of flights. There was significant variation in the structure of assemblages of large fauna among beaches, with those adjacent to riverine estuaries having greater richness and abundance of wildlife. Overall, drone surveys were successful in documenting the spatio-temporal dynamics of an impressive suite of large marine fauna. We contend that emerging drone technology can make a valuable contribution to the ecological information required to ensure the long-term sustainability of sandy-beach ecosystems and associated marine wildlife.

scholarly journals Novel Insights to Be Gained From Applying Metacommunity Theory to Long-Term, Spatially Replicated Biodiversity Data

2021 ◽  
Vol 8 ◽  
Author(s):  
Sydne Record ◽  
Nicole M. Voelker ◽  
Phoebe L. Zarnetske ◽  
Nathan I. Wisnoski ◽  
Jonathan D. Tonkin ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
The United States ◽  
Biodiversity Patterns ◽  
Spatial And Temporal Scales ◽  
Long Term Ecological Research ◽  
Spatial Replication ◽  
Spatio Temporal ◽  
Long Term Studies ◽  
Observation Networks

Global loss of biodiversity and its associated ecosystem services is occurring at an alarming rate and is predicted to accelerate in the future. Metacommunity theory provides a framework to investigate multi-scale processes that drive change in biodiversity across space and time. Short-term ecological studies across space have progressed our understanding of biodiversity through a metacommunity lens, however, such snapshots in time have been limited in their ability to explain which processes, at which scales, generate observed spatial patterns. Temporal dynamics of metacommunities have been understudied, and large gaps in theory and empirical data have hindered progress in our understanding of underlying metacommunity processes that give rise to biodiversity patterns. Fortunately, we are at an important point in the history of ecology, where long-term studies with cross-scale spatial replication provide a means to gain a deeper understanding of the multiscale processes driving biodiversity patterns in time and space to inform metacommunity theory. The maturation of coordinated research and observation networks, such as the United States Long Term Ecological Research (LTER) program, provides an opportunity to advance explanation and prediction of biodiversity change with observational and experimental data at spatial and temporal scales greater than any single research group could accomplish. Synthesis of LTER network community datasets illustrates that long-term studies with spatial replication present an under-utilized resource for advancing spatio-temporal metacommunity research. We identify challenges towards synthesizing these data and present recommendations for addressing these challenges. We conclude with insights about how future monitoring efforts by coordinated research and observation networks could further the development of metacommunity theory and its applications aimed at improving conservation efforts.

Long-term spatio-temporal dynamics of the mosquito Aedes aegypti in temperate Argentina

2016 ◽  
Vol 107 (2) ◽  
pp. 225-233 ◽  
Author(s):  
S. Fischer ◽  
M.S. De Majo ◽  
L. Quiroga ◽  
M. Paez ◽  
N. Schweigmann
Keyword(s):  
Aedes Aegypti ◽  
Buenos Aires ◽  
Temporal Dynamics ◽  
Spatial Dynamics ◽  
Climatic Conditions ◽  
Buenos Aires Province ◽  
Southern Limit ◽  
Spatio Temporal ◽  
Lower Temperature

AbstractBuenos Aires city is located near the southern limit of the distribution of Aedes aegypti (Diptera: Culicidae). This study aimed to assess long-term variations in the abundance of Ae. aegypti in Buenos Aires in relation to changes in climatic conditions. Ae. aegypti weekly oviposition activity was analyzed and compared through nine warm seasons from 1998 to 2014, with 200 ovitraps placed across the whole extension of the city. The temporal and spatial dynamics of abundances were compared among seasons, and their relation with climatic variables were analyzed. Results showed a trend to higher peak abundances, a higher number of infested sites, and longer duration of the oviposition season through subsequent years, consistent with a long-term colonization process. In contrast, thermal favorability and rainfall pattern did not show a consistent trend of changes. The long-term increase in abundance, and the recently documented expansion of Ae. aegypti to colder areas of Buenos Aires province suggest that local populations might be adapting to lower temperature conditions. The steadily increasing abundances may have implications on the risk of dengue transmission.

scholarly journals Arctic Greening Caused by Warming Contributes to Compositional Changes of Mycobiota at the Polar Urals

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1112 ◽  
Author(s):  
Anton G. Shiryaev ◽  
Pavel A. Moiseev ◽  
Ursula Peintner ◽  
Nadezhda M. Devi ◽  
Vladimir V. Kukarskih ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Soil Formation ◽  
Fungal Community Composition ◽  
Important Indicator ◽  
Polar Urals ◽  
Natural Park ◽  
Spatio Temporal ◽  
Special Environment ◽  
The Polar Urals

The long-term influence of climate change on spatio-temporal dynamics of the Polar mycobiota was analyzed on the eastern macro slope of the Polar Urals (Sob River valley and Mountain Slantsevaya) over a period of 60 years. The anthropogenic impact is minimal in the study area. Effects of environmental warming were addressed as changes in treeline and forest communities (greening of the vegetation). With warming, permafrost is beginning to thaw, and as it thaws, it decomposes. Therefore, we also included depth of soil thawing and litter decomposition in our study. Particular attention was paid to the reaction of aphyllophoroid fungal communities concerning these factors. Our results provide evidence for drastic changes in the mycobiota due to global warming. Fungal community composition followed changes of the vegetation, which was transforming from forest-tundra to northern boreal type forests during the last 60 years. Key fungal groups of the ongoing borealization and important indicator species are discussed. Increased economic activity in the area may lead to deforestation, destruction of swamps, and meadows. However, this special environment provides important services such as carbon sequestration, soil formation, protecting against flood risks, and filtering of air. In this regard, we propose to include the studied territory in the Polarnouralsky Natural Park.

scholarly journals Non-Invasive Monitoring of the Spatio-Temporal Dynamics of Vocalizations among Songbirds in a Semi Free-Flight Environment Using Robot Audition Techniques

Birds ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 158-172
Author(s):  
Shinji Sumitani ◽  
Reiji Suzuki ◽  
Takaya Arita ◽  
Kazuhiro Nakadai ◽  
Hiroshi G. Okuno
Keyword(s):  
Social Interactions ◽  
Temporal Dynamics ◽  
Acoustic Properties ◽  
Simple Method ◽  
Non Invasive ◽  
Robot Audition ◽  
Realistic Situation ◽  
The Social ◽  
Spatio Temporal

To understand the social interactions among songbirds, extracting the timing, position, and acoustic properties of their vocalizations is essential. We propose a framework for automatic and fine-scale extraction of spatial-spectral-temporal patterns of bird vocalizations in a densely populated environment. For this purpose, we used robot audition techniques to integrate information (i.e., the timing, direction of arrival, and separated sound of localized sources) from multiple microphone arrays (array of arrays) deployed in an environment, which is non-invasive. As a proof of concept of this framework, we examined the ability of the method to extract active vocalizations of multiple Zebra Finches in an outdoor mesh tent as a realistic situation in which they could fly and vocalize freely. We found that localization results of vocalizations reflected the arrangements of landmark spots in the environment such as nests or perches and some vocalizations were localized at non-landmark positions. We also classified their vocalizations as either songs or calls by using a simple method based on the tempo and length of the separated sounds, as an example of the use of the information obtained from the framework. Our proposed approach has great potential to understand their social interactions and the semantics or functions of their vocalizations considering the spatial relationships, although detailed understanding of the interaction would require analysis of more long-term recordings.

scholarly journals SPATIO-TEMPORAL STUDY OF BRAHMAPUTRA RIVER ISLANDS (CHARS) FOR AGRICULTURE EXPANSION IN ASSAM, INDIA

2019 ◽  
Vol XLII-3/W6 ◽  
pp. 429-433
Author(s):  
M. Prashnani ◽  
A. Qadir ◽  
J. Goswami ◽  
P. L. N. Raju
Keyword(s):  
Satellite Data ◽  
Temporal Dynamics ◽  
Cropping System ◽  
Google Earth ◽  
Brahmaputra River ◽  
Crop Cultivation ◽  
River Islands ◽  
Brahmaputra Valley ◽  
Spatio Temporal

<p><strong>Abstract.</strong> The present paper aims to understand the spatio-temporal dynamics of the Brahmaputra river islands locally known as chars in Assam for agriculture crop expansion using long term multispectral satellite data and Google Earth Engine. This study also provides information on existing agriculture lands on these chars. For the study Landsat data is analysed to find the long term stable islands (1988&amp;ndash;2018) and the present status of these islands for seasonal crop expansion. Validation of results was performed by using high-resolution satellite data. It is found that total area of vegetative chars has increased in past three decades and approximately 146 thousand hectares area of char is stable from past ten years. This study also reveals that the major crop cultivation is in Lower Brahmaputra Valley (LBV). In Upper Brahmaputra Valley (UBV), the crop cultivation is almost negligible compared to the large islands size. It can be inferred that less stable chars which are mostly located in upper Assam has negligible agriculture. It is also observed that at many places in lower Assam, double cropping system is followed. This study can be further extended by including factors like soil type, soil texture, rainfall, socio-economic etc. to study suitability for different crops. Proper facilities and incentives are to be provided to farmers of this region for better food security.</p>

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