scholarly journals Effects of season and food on the scatter-hoarding behavior of rodents in temperate forests of Northeast China

ZooKeys ◽  
2021 ◽  
Vol 1025 ◽  
pp. 73-89
Author(s):  
Dianwei Li ◽  
Yang Liu ◽  
Hongjia Shan ◽  
Na Li ◽  
Jingwei Hao ◽  
...  

To explore the differences in hoarding strategies of rodents for different seeds in various seasons, we labeled and released the seeds of Pinus koraiensis, Corylus mandshurica, Quercus mongolica and Prunus sibirica in temperate forests of Northeast China and investigated the fate of the seeds in spring and autumn. The analysis showed that the hoarding strategies of the rodents varied substantially between seasons. The seeds were consumed faster in the spring than in the autumn. More than 50% of the seeds in the two seasons were consumed by the 16th day. It took 36 days to consume 75% of the seeds in the spring and 44 days in the autumn. The rate of consumption of the seeds in the spring was greater than in the autumn, and the rate of spread of the seeds was greater in the autumn. The distances of removal for the consumption and dispersal of seeds in the spring (3.26 ± 3.21 m and 4.15 ± 3.52 m, respectively) were both shorter than those in the autumn (3.74 ± 3.41 m and 4.87 ± 3.94 m, respectively). In addition, the fate of different seeds varied significantly owing to differences in hoarding strategies. The seeds of the three preferred species, P. koraiensis, C. mandshurica, and Q. mongolica, were quickly consumed. More than 90% of the seeds of these species were consumed. Only 21% of Pr. sibirica seeds were slowly consumed, and the two seasons had the same seed consumption rate patterns: the consumption rate of P. koraiensis seeds was the highest, followed by C. mandshurica, then Q. mongolica, and finally Pr. sibirica. The median removal times of the two seasons were different, but the rules were the same: P. koraiensis was the shortest, followed by C. mandshurica, and the third was Q. mongolica. In both seasons, the most predated in situ seeds were those of P. koraiensis; the most hoarded seeds were those of C. mandshurica, and the most unconsumed seeds were those of Pr. sibirica.

2020 ◽  
Author(s):  
Simone Zen ◽  
Jan C. Thomas ◽  
Eric V. Mueller ◽  
Bhisham Dhurandher ◽  
Michael Gallagher ◽  
...  

AbstractA new instrument to quantify firebrand dynamics during fires with particular focus on those associated with the Wildland-Urban Interface (WUI) has been developed. During WUI fires, firebrands can ignite spot fires, which can rapidly increase the rate of spread (ROS) of the fire, provide a mechanism by which the fire can pass over firebreaks and are the leading cause of structure ignitions. Despite this key role in driving wildfire dynamics and hazards, difficulties in collecting firebrands in the field and preserving their physical condition (e.g. dimensions and temperature) have limited the development of knowledge of firebrand dynamics. In this work we present a new, field-deployable diagnostic tool, an emberometer, designed to provide measurement of firebrand fluxes and information on both the geometry and the thermal conditions of firebrands immediately before deposition by combining a visual and infrared camera. A series of laboratory experiments were conducted to calibrate and validate the developed imaging techniques. The emberometer was then deployed in the field to explore firebrand fluxes and particle conditions for a range of fire intensities in natural pine forest environments. In addition to firebrand particle characterization, field observations with the emberometer enabled detailed time history of deposition (i.e. firebrand flux) relative to concurrent in situ fire behaviour observations. We highlight that deposition was characterised by intense, short duration “showers” that can be reasonably associated to spikes in the average fire line intensity. The results presented illustrate the potential use of an emberometer in studying firebrand and spot fire dynamics.


2021 ◽  
Vol 14 ◽  
pp. 100656
Author(s):  
Nathalia Thygesen Vechi ◽  
Laura Mia Agneessens ◽  
Anders Feilberg ◽  
Lars Ditlev Mørck Ottosen ◽  
Michael Vedel Wegener Kofoed

1982 ◽  
Vol 20 ◽  
Author(s):  
P.P. Vaishnava ◽  
P.A. Montano

ABSTRACTIn situ 57Fe Mössbauer spectra are reported for the first-, higher-stage ferric chloride, and a mixed ferric chloride-potassium chloride intercalated graphite catalysts under reduction and Fischer-Tropsch reaction conditions. The mass spectroscopic measurements reveal a different catalytic selectivity for the three catalysts. The first two catalysts predominantly possess a higher selectivity for methane, whereas the third catalyst has higher selectivity for the formation of propane. The differences are attributed to geometrical effects in the catalytic sites of the intercalated compounds.


2007 ◽  
Vol 51 (04) ◽  
pp. 326-337
Author(s):  
K. Gasljevic ◽  
E. F. Matthys

We have investigated the feasibility of using high-molecular-weight polysaccharides produced by marine microalgae to reduce the drag on ships and therefore to be able to reduce the needed propulsion power and fuel costs or, alternatively, to increase the ship speed. Experimental and analytical studies were used to answer four critical questions:How suitable are the biopolymers for drag reduction on ships?What is the needed polymer consumption rate at a given level of drag reduction?What is the achievable polymer production rate that can be achieved by the microalgae?What are possible modes of implementation of the proposed technology? It is seen that in situ production of biopolymers by microalgae growing on the hull may be a possible approach to polymeric ship drag reduction. Production of biopolysaccharide off the ship and even harvesting it from the ocean are other possibilities. The use of biopolymers is naturally advantageous from an environmental point of view as well. Some comparison of biopolymers and synthetic polymers is also presented. Several technical issues remain to be investigated, but the information available suggests that biopolymers may be the best additives for drag reduction on ships.


2018 ◽  
Vol 26 (6) ◽  
pp. 467-469
Author(s):  
Masami Shingaki ◽  
Yoshihiko Kurimoto ◽  
Kiyofumi Morishita ◽  
Toshio Baba ◽  
Tsuyoshi Shibata ◽  
...  

An 83-year-old woman with a Kommerell diverticulum was treated by anatomical endovascular repair with a deep site in-situ fenestration instead of complex debranching techniques. The main component of the thoracic stent-graft was deployed just distal to the third cervical branch to completely exclude the Kommerell diverticulum. A deep site in-situ fenestration was made on the main component using a radiofrequency needle through the left subclavian artery, and a stent-graft was deployed to bridge the main component to the left subclavian artery. Six months postoperatively, the Kommerell diverticulum was completely excluded with excellent left subclavian artery patency.


2021 ◽  
Author(s):  
Mohd Baqar Raza ◽  
Pritam Nasipuri ◽  
Hifzurrahman

<p>The Banded Iron Formation (BIF) in Bundelkhand craton (BuC) occurred as supracrustals associated with TTG’s, amphibolites, calcsilicate rocks, and quartzite within the east-west trending Bundelkhand tectonic zone (BTZ). The BIFs near Mauranipur do not show any prominent iron-rich and silica-rich layer band and are composed of garnet, amphibole, quartz, and magnetite. The volumetrically dominant monoclinic-amphiboles are grunerite in composition. X<sub>Mg</sub> of grunerite varies between 0.39-0.37. The garnets are Mn-rich, the X<sub>Spss</sub> of garnet ranges from 0.26-0.20, X<sub>Pyp</sub> and X<sub>Grs </sub>vary between 0.10-0.06 and 0.07-0.05, respectively. P-T pseudosection analysis indicates that by destabilizing iron-silicate hydroxide phases through a series of dehydration and decarbonation reactions, amphibole and garnet stabilized in BIF at temperature 400-450°C and pressure 0.1-0.2 GPa.</p><p>Massive type BIFs have monazite grains that vary from 10 to 50 µm in size, yield three distinct U-Th-Pb<sub>total</sub> age clusters. 10-20 µm sized monazite grains yield the oldest age, 3098±95 Ma. 2478±37 Ma average age is obtained from the second group, which is relatively larger and volumetrically predominant. The third age group of Monaiztes gives an age of 2088±110 Ma. ~3100 Ma monazite suggests the older supracrustal rocks of Bundelkhand craton, similar to those obtained from Singhbhum and the Dharwar craton. The 2478±37 Ma age is constrained as the timing of metamorphism and stabilization of BuC. The third age group, 2088±110 Ma probably associated with renewed hydrothermal activities, leading to rifting and emplacement of mafic dykes in BuC.</p>


2019 ◽  
Vol 65 (No. 4) ◽  
pp. 134-143 ◽  
Author(s):  
Tuan Nguyen Thanh ◽  
Tai Dinh Tien ◽  
Hai Long Shen

Korean pine (Pinus koraiensis Sieb. et Zucc.) is one of the highly commercial woody species in Northeast China. In this study, six nonlinear equations and artificial neural network (ANN) models were employed to model and validate height-diameter (H-DBH) relationship in three different stand densities of one Korean pine plantation. Data were collected in 12 plots in a 43-year-old even-aged stand of P. koraiensis in Mengjiagang Forest Farm, China. The data were randomly split into two datasets for model development (9 plots) and for model validation (3 plots). All candidate models showed a good perfomance in explaining H-DBH relationship with error estimation of tree height ranging from 0.61 to 1.52 m. Especially, ANN models could reduce the root mean square error (RMSE) by the highest 40%, compared with Power function for the density level of 600 trees. In general, our results showed that ANN models were superior to other six nonlinear models. The H-DBH relationship appeared to differ between stand density levels, thus it is necessary to establish H-DBH models for specific stand densities to provide more accurate estimation of tree height.


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