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1

Diet composition and spatial patterns of food caching in wintering Great Grey Shrikes [Lanius excubitor] in Bulgaria

100%
Nikolov B. P., Kodzhabashev N. D., Popov V. V.
Biological Letters
|
2004
|
tom 41
|
nr 2
119-133
2

Modeling the spatial and temporal dispersal of Cuscuta europea (Cuscutaceae)

84%
Meri A., Karsai J.
Polish Journal of Ecology
|
2013
|
tom 61
|
nr 4
Cuscuta species are interestingly behaving plant parasites of very different plant communities all over the world. Under warmer climate conditions they can act as dangerous pests, while in the northern countries they are considered as threatened species. Moreover these plants have a special strategy to find their host, called foraging. Chemical clues emitted by the host plants attract the parasite shoots to the most proper host. Recent papers investigate the host preference of Cuscuta species. In our research, we examine the appearing spatial patterns with both experimental and modelling tools. Our objective is to reproduce this phenomenon in the virtual space and find the model, which best describes the emerging spatial patterns. For the modelling cellular automata are used, which are commonly used tools in spatial ecology. These are spatially explicit dynamic models, where both time and space are discrete. The graphical representation is a squared lattice. Every square – also called cell – in the lattice has a state (e.g. soil, plant, parasite) represented with an appropriate colour. In this paper we present the results of our field observations as well as the mathematical models considered.
3

Use of conventional and satellite data for estimation of evapotranspiration spatial and temporal pattern

84%
Struzik P., Kepinska-Kasprzak M.
Meteorology Hydrology and Water Management. Research and Operational Applications
|
2016
|
tom 04
|
nr 2
Evapotranspiration values (ET) are crucial for agriculture where estimates of water reserves available for crops are the basis for scheduling the time and intensity of irrigation, yield prognoses, etc. Detailed evapotranspiration data are, therefore, of essential value. However, stations performing direct measurements of evapotranspiration are very scarcely distributed in Poland, and for this reason the interpolation of data is necessarily biased. Hence, evapotranspiration values are calculated using indirect methods (usually empirical formulas). Data from geostationary meteorological satellites are used operationally for the determination of evapotranspiration with good spatial and temporal resolution (e.g. Land-SA F product). The study of the relation between evapotranspiration values determined with the use of satellite data and those calculated using the Penman-Monteith formula was performed for the study area in Poland. Daily values and cumulated (i.e. decadal, monthly and yearly) values were analysed to determine the quality and possible added value of the satellite product. The relation between the reference ET and actual ET in two consecutive years was discussed, both for the whole test area and for individual stations, taking into account land use and possible water deficit in the root zone, represented by H-SA F (EUMETSA T Satellite Application facility supporting Operational Hydrology and Water Management) soil wetness index product. The differences are presented and discussed.
4

Spatial pattern of trees of different diameter classes in managed pine stands (Pinus sylvestris L.) of different age

84%
Szmyt J.
Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria
|
2010
|
tom 09
|
nr 3-4
The present research was conducted in managed stands of Scots pine (Pinus sylvestris L.) at different age in Poland. All the investigated stands were planted and thinned according to selection thinning. Analysis of spatial structure concerned trees of different categories (DBH classess) depending on the age of stand. Spatial distribution of trees was investigated using two commonly used methods: Clark-Evans R index and Ripley's L(t) function. In stands of age 43 and 65 the effect of the initial spacing was observed and all living trees were distributed regularly at the smallest distances and at larger spatial scale they were spaced randomly. Random type of spatial structure of trees was observed when smaller and larger trees were taken into consideration, separately. In case of stands at the age 90 the effect of the initial planting on the spatial structure of trees was not observed even at the smallest distances independently of the category of trees taken into account. All living trees in these stands were distributed randomly. Only in two stands clumps of trees were observed and one concerned smaller trees and the other - larger trees. Size differentiation index was small for all stands. The lowest values was ascertained in the oldest stands.
5

Effect of tree layer and microsite on the variability of natural regeneration in autochthonous beech forests

84%
Vacek Z., Vacek S., Podrazsky V., Bilek L., Stefancik I., Moser W. K., Bulusek D., Kral J., Remes J., Kralicek I.
Polish Journal of Ecology
|
2015
|
tom 63
|
nr 2
European beech is a superior competitor among the trees of Central Europe, often growing in pure stands. We proposed a hypothesis, that once beech has reached dominance in forest community, it's recruitment could become limited due to the gradual accumulation of pathogens attacking seeds and seedlings. We employed data on seed production and germination along with a field experiment to estimate the germination success of beech in two old-growth forests. Beech produced more seeds than the co-occurring coniferous trees, but less than 1% of beechnuts germinated in the next season. In the field experiment, the percentage of decayed beechnuts was 57% in the Carpathians and 61% in the Alps. Most of the dead germinants and decayed beechnuts were infested by fungi. The average number of fungal colonies per one sample in the Carpathians was significantly higher after mast year than one year before, while the differences between the Alps and Carpathians after mast years were statistically not significant. Fungi have been isolated from practically all dead beechnuts and dead germinants. The number of beechnuts per seed trap, the number of germinants around it and the relative number of fungal colonies obtained from plastic boxes placed in the same sample plot were not significantly correlated. The mortality of germinants continued throughout the spring; the number of life germinants in the middle of May amounted to 0.87% of the initial number of beechnuts in the Carpathians and only 0.28% in the Alps. High rates of beechnut and germinant mortality could probably offset the huge reproductive effort of European beech in old-growth stands and limit the possibility to attain absolute dominance by that species. However, our hypothesis that the build-up of fungal pathogens on the forest floor old-growth stands is able to stop the regeneration of beech still needs to be tested using larger data sets.
6
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Post-fire succession on abandoned fields in coniferous forest habitat [Nord-East Poland]

84%
Kwiatkowska-Falinska A. J.
Acta Societatis Botanicorum Poloniae
|
2008
|
tom 77
|
nr 3
245-254
In July, 1992, fire swept through the Jelonka Reserve (52o35'33"N; 23o22'10"E). Litter, herbs layer and juniper shrubs were razed and the tree trunks of Pinus sylvestris and Populus tremula damaged, which resulted in their death the following year. Five research plots of 25 m2 each were established in the post-fire area. The species present there and their degrees of coverage were listed on the Londo scale between 1993 and 2002. The calculation of average degrees of coverage for individual populations allowed for the establishing of a chronological pattern of post-fire succession. The following findings have been made: 1) the primary function in colonization belongs to species of guerilla strategy of growth whose dormant buds survived fire underground (Holcus mollis, Calluna vulgaris and Populus tremula) or phalanx strategy of growth (Corynephoms canescens); 2) the dominants of the initial succession stage are perennial grasses, not therophytes; 3) the spatial pattern of succession is influenced by the occurrence of H. mollis or C. canescens in a particular location; 4) the initial stage terminates with the occurrence and further growth of C. vulgaris clumps; the post-fire succession in the Jelonka Reserve attained a brushwood stage faster in comparison to secondary succession, formerly triggered by the cessation of cultivation on arable land.
7
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Content available

Assessing the temporal stability of spatial patterns of soil apparent electrical conductivity using geophysical methods

84%
De Caires S. A., Wuddivira M. N., Bekele I.
International Agrophysics
|
2014
|
tom 28
|
nr 4
Cocoa remains in the same field for decades, resulting in plantations dominated with aging trees growing on variable and depleted soils. We determined the spatio-temporal variability of key soil properties in a (5.81 ha) field from the International Cocoa Genebank, Trinidad using geophysical methods. Multi-year (2008-2009) measurements of apparent electrical conductivity at 0-0.75 m (shallow) and 0.75-1.5 m (deep) were conducted. Apparent electrical conductivity at deep and shallow gave the strongest linear correlation with clay-silt content (R = 0.67 and R = 0.78, respectively) and soil solution electrical conductivity (R = 0.76 and R = 0.60, respectively). Spearman rank correlation coefficients ranged between 0.89-0.97 and 0.81-0.95 for apparent electrical conductivity at deep and shallow, respectively, signifying a strong linear dependence between measurement days. Thus, in the humid tropics, cocoa fields with thick organic litter layer and relatively dense understory cover, experience minimal fluctuations in transient properties of soil water and temperature at the topsoil resulting in similarly stable apparent electrical conductivity at shallow and deep. Therefore, apparent electrical conductivity at shallow, which covers the depth where cocoa feeder roots concentrate, can be used as a fertility indicator and to develop soil zones for efficient application of inputs and management of cocoa fields.
8
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Response patterns of phytoplankton growth to variations in resuspension in the German Bight revealed by daily MERIS data in 2003 and 2004

84%
Su J., Tian T., Krasemann H., Schartau M., Wirtz K.
Oceanologia
|
2015
|
tom 57
|
nr 4
9

The role of spatial distribution of faeces in coyote scent marking behaviour

84%
Barja I., List R.
Polish Journal of Ecology
|
2014
|
tom 62
|
nr 2
Scats are important for chemical communication in many canids, however, little is known about the faecal marking behaviour in coyotes. In this study we tested if faeces have a function as visual and scent marks during the non-breeding period, analyzing the spatial characteristics of defecation places. We predicted that if faeces are used as chemical signals, these should be deposited in substrates and/or zones that enhance their detection by conspecifics as it happens in other canid species. The study was conducted in native grasslands at the NW limit of the Chihuahuan Desert. Results showed that the proportion of faeces in conspicuous zones (91.3%) was significantly higher than those on inconspicuous zones (8.7%). However, the number of faeces deposited on inconspicuous substrates (92.1%) was significantly higher than on conspicuous substrates (7.9%). Most faeces were on the ground (99.2%) and only 0.8% where raised. 35% of faeces were deposited in crossroads, being these strategic zones repeatedly marked by the coyotes. We observed a significant negative correlation between the number of faeces in crossroads and the distance of faeces to the centre of the crossroad. A high number of scats were found in the proximity of livestock carcasses (21%). In addition, a selection of certain road sections (track and lateral) was observed. Our results suggest that the scats have an important function as scent-marks in coyotes, using specific defecation patterns that appear to correspond to the habitat characteristics in the study area.
10

Analysis of spatial point pattern shows no desertion of breeding Mute Swan areas by the other waterbirds within fishpond

84%
Gayet G., Calenge C., Broyer J., Mesleard F., Vaux V., Fritz H., Guillemain M.
Acta Ornithologica
|
2016
|
tom 51
|
nr 2
Mute Swan Cygnus olor numbers have recently increased in a dramatic fashion in Western Europe and in North America, suggesting there could be potential consequences for the rest of the waterbird community. Breeding Mute Swan pairs may behave territorially towards other waterbirds, taking advantage of their larger size, and hence cause concern regarding their potential effects on waterbird communities. We studied how the within-site distributions of breeding Mute Swans and other waterbirds were related to each other, in order to assess if there is support to the assertion that breeding Mute Swans may affect the distribution of the other waterfowl within waterbodies. We mapped waterbird and swan distribution within fishponds during the Mute Swan breeding period. Relying on spatial point pattern analysis, our first finding is that breeding Mute Swans were located in the vicinity of the other waterbirds, using the same area within fishpond. Waterbirds do not completely desert the area used by breeding swan pairs within a waterbody, hence not supporting the claim that Mute Swans dislodge the other species. If an exclusion process by Mute Swan breeding pairs towards waterbirds exists, it is not strong enough to generate deserted areas by waterbirds around breeding Mute Swans. Our second finding is that breeding Mute Swans were not located where the density probability function for waterbird presence was the greatest within a fishpond, i.e. breeding Mute Swans were not located in the centre of groups formed by other waterbirds within each fishponds. This may indicate slightly different micro-habitat preferences or use within fishponds, or could indicate the potential occurrence of interactions. In conclusion, these results question whether the increasing Mute Swan populations actually directly threaten the other waterbird communities in such habitats, and require population control as is often claimed.
11

Spatial pattern of potamozooplankton community of the slowly flowing fishless stream in relation to abiotic and biotic factors

84%
Czerniawski R.
Polish Journal of Ecology
|
2012
|
tom 60
|
nr 2
While the knowledge about spatial structure of zooplankton communities in large rivers has been relatively well studied, little is known on the longitudinal spatial variation of zooplankton in small, slowly flowing fishless streams. In these streams, changes in zooplankton communities along entire length of the stream can be quite different than in those where young planktivorous stages of fish reduce the abundance of zooplankton. The aim of this study was to answer the following questions. What is the spatial pattern of the taxonomic groups of zooplankton in the slow-flowing stream? Do the small tributaries have an impact on the zooplankton community in the main stream? What biotic variables (content of chlorophyll a, vegetation coverage, macroinvertebrates abundance) and abiotic variables (temperature, dissolved oxygen, pH, conductivity, N-NO3, N-NO2, N-NH3, TN, P-PO4, TP, width, depth, current velocity, discharge) most affect the zooplankton community in a small stream? This study was performed at six sites along a small (1 km long, mean width 1.7 m; mean depth 0.3 m; mean current velocity 5.9 cm s-1; mean discharge 2.6 cm3 s-1, mean vegetation coverage 52%) fishless agricultural-meadow stream and at one site in its two tributaries. The stream was searched with the use of electric fish gear to make sure there were no fish. Zooplankton samples were collected each month throughout the years 2008 and 2009. The main factors which affected the zooplankton communities were hydrological conditions, especially current velocity. Water current in the stream impeded the movement of rotifers and juvenile copepods. Adult copepods were able to manage in the current, over the entire length of the stream. Cladocerans probably were only able to persist in the last section of the watercourse flow, where the velocity was the lowest (3.3 cm s-1) and where the content of chlorophyll a was the highest (56.2 μg L-1 ). The two tributaries had only a small effect on shaping of the zooplankton communities in the main stream. On the basis of Pearson correlations it can be concluded that macroinvertebrate had a low ability to reduce the density of zooplankton, all significant correlations between the abundance of potamozooplankton and that of macroinvertebrates were positive.
12

Temporal and spatial patterns of aboveground biomass and its driving forces in a subtropical forest : a case study

84%
Ma L., Li W., Shi N., Fu S., Lian J., Ye W.
Polish Journal of Ecology
|
2019
|
tom 67
|
nr 2
13

Use of microsatellite markers to assess the spatial genetic structure of a population of sika deer Cervus nippon on Kinkazan Island, Japan

84%
Okada A., Tamate H. B., Minami M., Ohnishi N., Takatsuki S.
Acta Theriologica
|
2005
|
tom 50
|
nr 2
To understand the relationship between social behaviour and gene distribution, we used microsatellite markers to resolve the spatial genetic structure of the sika deerCervus nippon Temminck, 1838 population on Kinkazan Island, a small island (9.6 km2) in northern Japan. We obtained 177 samples of deer which correspond to about 30% of the total population on the island. 126 were from a local population where each deer was individually identified, while 51 from other area on the island. Although there were no apparent geographical barriers on the island, the sika deer population showed local differentiation in its genetic composition. By comparing allele-sharing rates between gender and social categories, we demonstrated a higher genetic relatedness within males in a local group. The Assignment Index (AI) of each sex within a local group showed similar distributions. None of our analyses indicated a lower genetic relatedness among males than females, which contradicted our predictions based on the dispersal behaviour of males. Considering other factors, the results suggest that the range of male dispersal is quite limited on this island.
14
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Content available

Spatial patterns of the wave climate in the Baltic Proper and the Gulf of Finland

67%
Soomere T., Raamet A.
Oceanologia
|
2011
|
tom 53
|
nr (1-TI)
We make an attempt to consolidate results from a number of recent studies into spatial patterns of temporal variations in Baltic Sea wave properties. The analysis is based on historically measured and visually observed wave data, which are compared with the results of numerical hindcasts using both simple fetch-based one-point models and contemporary spectral wave models forced with different wind data sets. The focus is on the eastern regions of the Baltic Sea and the Gulf of Finland for which long-term wave data sets are available. We demonstrate that a large part of the mismatches between long-term changes to wave properties at selected sites can be explained by the rich spatial patterns in changes to the Baltic Sea wave fields that are not resolved by the existing wave observation network. The spatial scales of such patterns in the open sea vary from >500 km for short-term interannual variations down to about 100 km for long-term changes.
15

Temporal and spatial patterns of seed dispersal of Musa acuminata by Cynopterus sphinx

67%
Tang Z., Sheng L., Ma X., Cao M., Parsons S., Ma J., Zhang S.
Acta Chiropterologica
|
2007
|
tom 09
|
nr 1
The foraging behavior of greater short-nosed fruit bats (Cynopterus sphinx) on wild banana (Musa acuminata) and subsequent dispersal of seeds were studied in the Tropical Rainforest Conservation Area, Xishuangbanna Tropical Botanical Garden, Yunnan province, by direct observation of marked fruits, mist netting, and seed collection. The mean number (± SE) of individual C. sphinx captured by mist net were 2.2 ± 0.33/day and 1.4 ± 0.32/day in the rainy season (September to October) and dry season (November to December), respectively; the difference was not significant. The number of seed pellets expelled was 9.0 ± 1.12/day and 7.2 ± 1.37/day in the rainy and dry seasons respectively; again the difference was not significant. The removal curves for marked fruit were similar for 10 focal trees. Fruits were consumed heavily within two weeks after ripening and all the marked fruit were removed within one month. The difference in seed dispersal was significant between different feeding roosts indicating that patterns of seed dispersal may not be uniform. We found the seeds of M. acuminata can be dispersed by C. sphinx to a distance of about 200 m, and C. sphinx can be considered as an effective seed disperser of M. acuminata.
16

Spatial patterns and coexistence of the native forb, Psathyrostachys fragilis (Asteracea) and the native invader, Gundelia tournefortii (Poaceae) in a semi-arid rangeland of Iran

67%
Khojasted F., Chahouki M. A. Z.
Polish Journal of Ecology
|
2013
|
tom 61
|
nr 2
In this study, we investigated the interactions between the dominant native invader, Gundelia tournefortii, and the dominant forage species, Psathyrostachys fragilis in rangelands of Taleghan (Iran). Four transects of 150 meters were considered as sampling unit. Using randomly-systematic method, 15 plots (1 × 1m) were placed along each transect with a distance of 10 m. List of species, the canopy cover and the numbers of plant species were determined in each plot. The spatial association of the two dominant species was assessed by studying association, covariation, and distribution pattern (using the Hopkins’ index) of plants. We found a clumped distribution pattern in both two dominant species. Results of this study revealed a strong competitive interaction between the dominant plant species in studied area with P. fragilis was more frequent and had more canopy cover than the native invader G. tournefortii. So, according to our findings, P. fragilis may present a suitable candidate for artificial re-vegetating and protecting against invaders to restore the biodiversity and ecological health of endangered rangelands.
17

The mosaic diversity of ground vegetation along the transect through the transition zone from the pure coniferous to the mixed coniferous site in the Bialowieza Primeval Forest in North-Eastern Poland

67%
Bobiec A.
Fragmenta Floristica et Geobotanica
|
1994
|
tom 39
|
nr 2
18

Stream habitats, benthic macroinvertebrates, lotic fish and their relationships: a multi-scale approach

67%
Fleituch T., Amirowicz A.
Polish Journal of Ecology
|
2005
|
tom 53
|
nr 1
A natural reach of montane stream (length 96 m and 7 m width) was grided into 150 cells (2 × 2 m). Density and biomass of fish (Salmo trutta L. and Cottus poecilopus Heckel) were estimated at each cell, as well as stream depth, current velocity, Froude number, bed granulation and its roughness were measured, and benthic samples from exposed bricks were collected from mid August to early October. The analysis of spatial patterns of seven variables (five abiotic and two biotic ones) and fish occurrence from the period of highest organisms’ abundance confirmed that two fish species were separated within the stream space and sculpin showed close association to benthic prey. The PCA pointed to the highest loadings of abiotic habitat variables (64% of the total variance) indicating importance of hydraulics (stream velocity and Froude number) and bed characteristics (stream depth and bed roughness) in distribution of fish communities in pristine low order streams.
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