seasonal patterns
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Author(s):  
G.F. Turrisi ◽  
S. Bella ◽  
R. Catania ◽  
P. La Greca ◽  
V. Nobile ◽  
...  

The present three-year study traces the diversity of four bee communities in fragmented pedemontane areas of Volcano Etna (Catania province, Sicily) near the Metropolitan City of Catania, under different land management regimes. The selected areas comprise two different urban parks within Catania (Parco Gioeni and Parco degli Ulivi), a Nature Reserve (Complesso Immacolatelle e Micio Conti, San Gregorio di Catania), and an agroecosystem (a citrus orchard, Aci Catena). Previous data obtained from a well-investigated area (Leucatia, north of Catania) have been used as a control for bee diversity for this study. The results include an outline of bee species richness, data on the composition of bee communities, and seasonal patterns, using several diversity indexes. The study of bee diversity shows a total of 163 species, arranged in five families. The four investigated locations include 104 species arranged in four families: Andrenidae (20 species), Halictidae (15 species), Megachilidae (31 species), and Apidae (38 species); with a similar number of species (102) recorded in the control site (Leucatia). The study highlights strong seasonal variations of bee communities in all investigated sites, with differentiated seasonal patterns, whose compositions are affected mainly by forage sources, suitable nesting sites, as well as human activities. The data obtained provide a rough but basilar framework to assess management strategies to maintain adequate levels of bee diversity, especially for those areas with moderate to high environmental fragmentation. Our findings highlight the importance of season-long sampling of bee population factors if used as indicators in ecological studies.


Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 99
Author(s):  
Deanna S. Scheff ◽  
James F. Campbell ◽  
Franklin H. Arthur

The lesser grain borer, Rhyzopertha dominica (F.), is a highly diverse feeder and widely distributed throughout the United States in agricultural and non-agricultural landscapes. Six four-funnel Lindgren traps were deployed in feed mill, grain elevator, and native prairie landscapes, to determine the most attractive food and pheromone combination (attractant) and patterns in seasonal captures. Traps were baited with combinations of wheat (crimped, high moisture, pre-fed) with or without an R. dominica specific aggregation pheromone in 2017 and 2018. Traps were deployed for 48 h, collected, and the number of R. dominica counted. Rhyzopertha dominica was captured among all landscapes with all attractants. There was a significant correlation between temperature and R. dominica captures, with peak captures occurring during the warmest months. Significantly more R. dominica adults were captured in traps containing the pheromone. In 2017, pheromone traps captured 818% more R. dominica and 543% more than in 2018. The pheromone component in the trap was more attractive than any natural stored wheat condition and should be included in future studies. Understanding the seasonal patterns and changes in capture rates in agricultural and non-agricultural landscapes may be useful in determining times of increased immigration pressure into the newly harvested grain.


2021 ◽  
Vol 80 (04) ◽  
pp. 120-128
Author(s):  
Carla V. DAGATTI ◽  
Gabriela A. VARGAS

Exclusive to the Neotropical region, leaf cutter ants are considered agricultural pests, although they can also have a positive effect on plants. In Mendoza vineyards, vegetal biodiversity is minimal, therefore they cut off this plant as a feeding resource. Acromyrmex lobicornis Emery it is mostly nocturnal and forages according to temperature. Foraging and maintenance activity was measured monthly in 14 colonies, throughout a full day at fourhour intervals, from October 2019 to March 2020. Acromyrmex lobicornis showed different seasonal patterns of foraging activity. Foraging intensity was highest throughout January and February, intermediate during December, and lowest in October and November. A bimodal feeding pattern was observed, foraging both day and night avoiding the hottest hours. The maximum collection of fragments was observed in the range of 10 and 19 °C, less between 20 - 39 °C, minimum between 40 - 49 °C and null between 0 - 9 °C. The nest - maintenance activity was maximum between 20 - 29 °C, less between 30 - 39 ° C, minimum between 40 - 49 °C and null between 0 - 20 °C.


Author(s):  
Alexander Dokumentov ◽  
Rob J. Hyndman

We propose a new method for decomposing seasonal data: a seasonal-trend decomposition using regression (STR). Unlike other decomposition methods, STR allows for multiple seasonal and cyclic components, covariates, seasonal patterns that may have noninteger periods, and seasonality with complex topology. It can be used for time series with any regular time index, including hourly, daily, weekly, monthly, or quarterly data. It is competitive with existing methods when they exist and tackles many more decomposition problems than other methods allow. STR is based on a regularized optimization and so is somewhat related to ridge regression. Because it is based on a statistical model, we can easily compute confidence intervals for components, something that is not possible with most existing decomposition methods (such as seasonal-trend decomposition using Loess, X-12-ARIMA, SEATS-TRAMO, etc.). Our model is implemented in the R package stR, so it can be applied by anyone to their own data.


2021 ◽  
Author(s):  
Muhammad Fahmi Zuhdi ◽  
Hawis Madduppa ◽  
Neviaty Putri Zamani

Abstract Coral reef fish populations are declining due to multiple factors including habitat destruction, overfishing, and climate change. While these can include seasonal impact, seasonal changes can also be a confounding factor, so that seasonal monitoring is essential for detecting true temporal changes in fish community abundance and composition. However, seasonal monitoring is rarely implemented. The aim of this study was to detect the seasonal patterns of coral reef fish community structure around Tidung Kecil Island, Indonesia, using eDNA metabarcoding (eDNA) and underwater visual census (UVC). The UVC identified 32 species belonging to 10 families in the rainy season and 29 species belonging to 7 families in the dry seasons. The eDNA metabarcoding identified 209 species belonging to 56 families and 27 species belonging to 17 families in the rainy and dry seasons, respectively. Based on eDNA metabarcoding data, coral reef fish abundance and community composition differed significantly between seasons (Mann Whitney, p<0.01), while the UVC method did not detect these seasonal differences (Mann Whitney, p>0.05). UVC and eDNA data both showed a predominance of omnivorous fishes in the rainy season and carnivorous fishes in the dry season. Ecological indices did not differ significantly between seasons for either method, although the species making the highest contributions to the similarity (SIMPER) analysis differed between methods. Overall, this study confirms the premise that eDNA metabarcoding can be an effective tool for monitoring seasonal variation in coral reef fish communities.


2021 ◽  
Author(s):  
◽  
Alexander Dixson

<p>Sexual selection and the mating system of the Wellington tree weta has been extensively studied during the last 15 years. In the past 10 years, nutritional ecology and factors affecting the distribution of species in the genus Hemideina have also been examined in great detail. This recent work and the extensive studies of New Zealand tree weta species that preceded it provide much context and comparison for this thesis, which examines the ecology of a population of tree weta living on Matiu/Somes Island. Less is known about factors affecting the development of the exaggerated male weaponry that is characteristic of much of the genus Hemideina.   This thesis firstly presents a mark-recapture study conducted over 42 months on Matiu/Somes Island to obtain ecological information about the population. Secondly, this thesis presents an experiment on the effects of protein supplement on growth and weaponry in male Wellington tree weta derived from the Matiu/Somes Island population. The results of the field study indicate that male tree weta live longer than females on Matiu/Somes Island and weapon size is positively related to adult longevity of males. Seasonal patterns shown in the population on Matiu/Somes Island and inferences about aspects of their life cycle are discussed. Female tree weta on Matiu/Somes Island formed harems throughout each year and there was a positive relationship between males weapon size and the number of females in a harem. Results do not indicate seasonal differences in harem-forming behaviours of females. The results of the captive rearing study include a shorter development time and larger weaponry as adults in males raised on a protein supplemented diet, compared to individuals raised on an entirely herbivorous diet. Details of differences in the course of development are also discussed for the two diet treatment groups.</p>


2021 ◽  
Author(s):  
◽  
Alexander Dixson

<p>Sexual selection and the mating system of the Wellington tree weta has been extensively studied during the last 15 years. In the past 10 years, nutritional ecology and factors affecting the distribution of species in the genus Hemideina have also been examined in great detail. This recent work and the extensive studies of New Zealand tree weta species that preceded it provide much context and comparison for this thesis, which examines the ecology of a population of tree weta living on Matiu/Somes Island. Less is known about factors affecting the development of the exaggerated male weaponry that is characteristic of much of the genus Hemideina.   This thesis firstly presents a mark-recapture study conducted over 42 months on Matiu/Somes Island to obtain ecological information about the population. Secondly, this thesis presents an experiment on the effects of protein supplement on growth and weaponry in male Wellington tree weta derived from the Matiu/Somes Island population. The results of the field study indicate that male tree weta live longer than females on Matiu/Somes Island and weapon size is positively related to adult longevity of males. Seasonal patterns shown in the population on Matiu/Somes Island and inferences about aspects of their life cycle are discussed. Female tree weta on Matiu/Somes Island formed harems throughout each year and there was a positive relationship between males weapon size and the number of females in a harem. Results do not indicate seasonal differences in harem-forming behaviours of females. The results of the captive rearing study include a shorter development time and larger weaponry as adults in males raised on a protein supplemented diet, compared to individuals raised on an entirely herbivorous diet. Details of differences in the course of development are also discussed for the two diet treatment groups.</p>


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