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Artykuły w czasopismach na temat "Grassland-forest complexes"
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Adams, M. L., M. R. Davis i K. J. Powell. "Effects of grassland afforestation on exchangeable soil and soil solution aluminium". Soil Research 39, nr 5 (2001): 1003. http://dx.doi.org/10.1071/sr00054.
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The impact of land use change from grassland to conifer forest on the aluminium (Al) concentrations in soils and soil solutions was examined. Soils from grassland were compared with those from adjoining 15–19-year old forest stands at 3 contrasting pairs of sites in South Island, New Zealand. The site pairs were on a terrace [Pinus nigra/P. ponderosa, and grassland (CP)], and a hill slope [Pseudotsuga menziesii and grassland (CF)] in the Craigieburn range, Canterbury, and a hill slope in the Lammerlaw Range, Otago [P. radiata and grassland (LP)]. The sites had never been cultivated or fertilised, and for each pair the forest and grassland were similar in terms of soil and topography. The 1 M KCl exchangeable and 0.02 M CaCl 2 extractable Al levels at 0–10 cm were higher in forest than in grassland topsoil at CP and LP (P < 0.01). In soil solutions there was a trend for both ‘reactive Al’ and Al bound in labile organic complexes to be higher in forest soil at all sites, but site-pair differences were only significant at LP, and only for ‘reactive Al’. The increase in ‘reactive Al’ at this site was linked to the low pH and low base saturation. The ratios of exchangeable and soil solution Ca 2+ and Mg 2+ to ‘reactive Al’ were substantially lower in forest than grassland soils at all sites. Aluminium complexation capacity (Al-CC) values at all sites were higher in forest soil solutions than in grassland soil solutions. For the grassland and forest sites at LP, the Al-CC correlated strongly with the amount of soluble fulvic and humic matter present, as estimated from soil solution UV absorbance at 250 nm. In soils with the lowest percentage base saturation and buffering capacity (LP), afforestation of pastoral grassland with Pinus radiata significantly reduced soil pH and base cation levels, while increasing both soil and soil solution Al concentrations. Under such conditions (base saturation <20%), the increase in ‘reactive Al’ concentrations in soil solutions under fast growing conifer tree species may be sufficient to affect Mg uptake.
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Zachar, Zalán, Gergely Pápay, Péter Csontos, Gábor Szabó, Zita Zimmermann, Dénes Saláta, Szilárd Szentes, Ferenc Pajor, Márta Fuchs i Károly Penksza. "The Effects of Different Management Methods on Restored Grasslands in Potential Temperate Forest Zones". Diversity 14, nr 7 (8.07.2022): 551. http://dx.doi.org/10.3390/d14070551.
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The European temperate forest zone has great importance, in terms of maintaining the habitats of not only forests but also anthropogenous grasslands, which were formed as a result of habitat reconstruction. These habitats have great importance, by means of nature conservation, landscape use, economy, and forest and grassland use. The mosaic-like habitat complexes that consist of these grasslands and forest patches help to increase biodiversity and supply the habitat for forest game. In this survey, changes in the vegetation of the temperate forests (Fagetum) of the Mátra Mountains of Hungary were investigated after reconstruction. In 2012, shrub cutting was carried out in the area of Parádóhuta, and then three different management methods (abandoning, mowing, and grazing) were utilized. Our goals were the following: to perform a vegetation survey of the sample areas (i); surveying the natural regeneration of the grassland and analyzing its biodiversity, nature conservation, and economical value (ii); and analyzing the vegetation in terms of nature conservation and valuing its life form spectrum, economy values, and livestock-feeding ability (iii). According to our results, systematic mowing and a less-intensive grazing had a significantly positive effect on biodiversity and the coverage of species, thus increasing the naturalness of the studied grassland habitats, while wild game were able to act as ecological engineers.
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Strickland, A. J., J. M. Arocena, P. Sanborn i C. A. S. Smith. "Secondary mineral formation in the White River tephra in grassland and forest soils in central Yukon Territory". Canadian Journal of Soil Science 85, nr 5 (1.11.2005): 637–48. http://dx.doi.org/10.4141/s05-001.
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Selected surface horizons of grassland and forest soils formed under a cold, semi-arid climate were investigated to evaluate the formation of secondary minerals within the White River tephra, a Late Holocene rhyolitic tephra (~115014C yr BP) veneer that overlies the soil landscapes of central Yukon. Concentrations of extractable Fe (< 0.48%), Al (< 0.26%) and Si (< 0.082%) concentrations in surface tephra-contaning horizons of grassland and forest pedons are low. The high amount of exchangeable calcium in grassland soils is likely due to cycling by vegetation and perhaps, aeolian inputs of Ca and Mg carbonates. Al is incorporated into Al-humus complexes in forest pedons and allophane in grassland pedons. Allophane content is low (< 0.56%) in all soils as is ferrihydrite (< 0.34%). Mineral composition of the sand fraction from tephra horizons is dominated by volcanic glass, plagioclase feldspars, amphiboles, epidote, pyroxenes and very limited quantities of quartz and primary Fe oxides. Chlorite and an expanding phyllosilicate were also detected and are assumed to be of detrital origin. Clay mineralogy is dominated by volcanic glass, quartz, feldspars and minimal quantities of kaolinite and dehydrated halloysite in surficial horizons. Kaolinite is assumed to be of detrital origin while dehydrated halloysite is a product of a low leaching and dry environment where limited resilication occurs. Scanning electronmicroscopy (SEM) investigation indicates the presence of opaline silica in surface horizons from forest pedons which has likely formed due to freezing of the soil solution in combination with dehydration and resilication. Overall, the soil horizons formed within the veneer of White River tephra have experienced minimal weathering and very little silicate clay mineral development. Key words: Tephra, glass, Yukon, minerals (secondary), weathering
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Kilianová, Helena, Vilém Pechanec, Jan Brus, Karel Kirchner i Ivo Machar. "Analysis of the development of land use in the Morava River floodplain, with special emphasis on the landscape matrix". Moravian Geographical Reports 25, nr 1 (1.03.2017): 46–59. http://dx.doi.org/10.1515/mgr-2017-0005.
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AbstractThe results of an analysis of land use development in the Morava River floodplain (Czech Republic) using GIS from 1836 to the present, are the subject of this article. The results are based on the analysis of historical maps, using the landscape matrix assessment of the Morava River floodplain. The final analyses were processed from land use maps of the floodplain at a scale of 1 : 25,000 in five time horizons. These maps were compared with the present state of landscape by GIS methods. The study area was assessed according to five geomorphological areas from the northern/higher part to the southern/lower part of floodplain. In 1836 the landscape matrix of the floodplain was composed of meadows and forests. Forest components decreased minimally but the changes are more important. The grassland area (meadows and pastures) decreased but arable land, as well as settlements, increased very significantly. In the 1950s the landscape matrix was composed of a mosaic of alluvial forests, meadows and arable land. Currently, the predominant landscape matrix consists of arable land and isolated forest complexes.
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Zheng, Haibo, Liwei Zhang, Pengtao Wang i Yingjie Li. "The NPP-Based Composite Indicator for Assessing the Variations of Water Provision Services at the National Scale". Water 11, nr 8 (7.08.2019): 1628. http://dx.doi.org/10.3390/w11081628.
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Water provision (WP) is an important service of the terrestrial ecosystem, which contributes to water availability for consumptive use and in situ water supply, sustains the production or flows of multiple ecosystem services (ES). Spatially explicit mapping of WP is critical for incorporating the ES concept into the decision-making processes of land-use and ecological conservation planning. Traditionally, regional complexes hydrological process models were simplified and used for mapping WP of the ecosystem at broad scales, but this approach is significantly limited by data accessibility and difficulty validating the results. To fill the gap, an NPP-based composite indicator model that simulates WP by multiplying NPP and its variations with the soil infiltration capacity factor, annual precipitation and the slope of the land surface is proposed in this paper. These parameters are chosen to map WP because they are closely related to hydrological processes. The model results were validated using observed runoff data of the eleven river basins in China. We then applied this approach to analyze the spatiotemporal changes of WP in China from 2000 to 2013. The results show that: (1) the average value of WP was lowest in the Northwest Arid Area ecoregions while the highest value of WP was in the South China ecoregion. (2) The linear trend of WP in the Loess Plateau and Hengduan Mountains ecoregions were increased while decreased in the other nine ecoregions. (3) The WP in the north of the Qinghai-Tibet Plateau presented a significant decrease trend mostly because the land cover change (e.g., grassland convert into dessert) and decreasing precipitation; the decreasing of the WP in Yunan-Guizhou Plateau are because the farmland convert into settlement land and the significant decrease of precipitation and significantly increase of temperature; the significant increase of the WP in Northeast China are because the increasing of forest and farmland, the grassland and wetland convert into farmland and forest, and the significant decrease of temperature and increase of precipitation; Although the increase of precipitation has played an important role in promoting WP, the significant increase of WP in the Loess Plateau was mainly due to the farmland convert into forest and grassland ecosystem types. The indicator explored by this research is benefiting for revealing the variations of WP under different land-use change and climate change, and informed the decision-making process of land-use policy or conservation planning at data-scarce regions or broaden spatial scales.
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Vysochyn, M. O. "Population dynamics and types of habitats at breeding sites of raptors (Falconiformes) of the Donetsk Ridge along a gradient of anthropogenic disturbance". Regulatory Mechanisms in Biosystems 10, nr 4 (6.11.2019): 464–69. http://dx.doi.org/10.15421/021968.
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Studies of diurnal birds of prey may be quite indicative of the state of natural ecosystems and of the level of impact of human-induced factors on their functions. The aim of this work was to analyse the long-term dynamics of the raptor populations within the Donetsk Ridge, to identify which habitat or habitat mosaics are preferred in nesting territories and home ranges depending on the level of anthropogenic transformation of the environment. The studies were conducted in 1999–2019. The total length of the walking routes was 2,864 km while a distance of 1,548 km was covered by car routes. 306 nests of the birds of prey or those potentially belonging to the members of this group were found and re-examined. The long-term dynamics of the population of Falconiformes was characterized by a general decline in the numbers of most species. There was a loss of representatives of the boreal and desert-steppe faunistic complexes and simultaneous increase in the participation of representatives of the nemoral and forest steppe faunistic complexes associated with the floodplain forests of the Siversky Donets River valley and the bayrak oak forests of the central part of the Donetsk Ridge. The impact of the anthropogenic factor on the dynamics of the population of the birds of prey is ambiguous. For the species which are sensitive to changes in the environment, such as the European Honey Buzzard, the Northern Goshawk, the Merlin and the Red-footed Falcon, a general negative dynamics of the populations is observed. The positive trend in the numbers of the Long-legged Buzzard and the Saker Falcon is linked to the expansion of the both species into the territory of the Donetsk Ridge. The habitat structure of the nesting territories is quite diverse in different species of diurnal birds of prey. This is especially noticeable in the ratio of forest and grassland habitats. Based on the selectivity index, we found that the vast majority of the raptors of the Donetsk Ridge prefer temperate broad-leaved forests when choosing nesting territories. The structure of the home ranges of all forest species of diurnal birds of prey not only depends on the optimal ratio of open and forested areas but on the presence of ecotones of considerable length which originated in the complex mosaics of habitat complexes. The stable number of dendrophiles and the disappearance (decrease in number) of sclerophiles and campophiles indicates the least anthropogenic transformation of forest habitats and a radical transformation of open spaces – meadows and steppes. The most successful were eurytopic birds of prey and species with pronounced anthropotolerance.
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Eugene Singayevskiy, Eugene Singayevskiy, Paul Balan i Yeho Hrynyk. "TO THE STUDY OF THE FAUNA OF SPIDERS (ARACHNIDA, ARANEI) OF THE CHERNIHIV POLISSIA: SPIDERS OF THE BYKIVNIAN FOREST AREA OF THE CITY OF KYIV". Bulletin of Taras Shevchenko National University of Kyiv. Series: Biology 91, nr 4 (2022): 28–35. http://dx.doi.org/10.17721/1728.2748.2022.91.28-35.
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For the first time, a study of the species composition of spiders of the Bykivnyan forest area, which is located within the eastern outskirts of the city of Kyiv and the southern borders of Chernihiv Polissia, was conducted. Vegetation layers and litter of pine and birch forests and psamophilous grass habitat were examined. 123 species of spiders belonging to 21 spider families have been identified. The most widely represented in the faunal assemblages are the family Linyphiidae – 28 species (22.8 % of the total number of species detected), Gnaphosidae – 17 (13.8 %) and Lycosidae – 15 species (12.2 %). Pardosa lugubris was the most massive species in the litter layer of the pine forest. The Lycosidae family is also the most widely represented in the litter layer, accounting for 41.8 % of the total number of specimens. The share of representatives of the Gnaphosidae and Linyphiidae families was 24.6 % and 12.5 %, respectively. Taking into account the literature data and the obtained results, the araneofauna of Chernihiv Polissia currently includes at least 389 species from 29 spider families. 26 species from 13 spider families were identified, which are indicated for the first time for Chernihiv Polissia, including 14 species from 8 spider families that are new to the territory of Ukrainian Polissia. For species new to the region, data on faunal material, period of time, place and the method of collection, ecological features and findings of these species on the territory of Ukrainian Polissia are given. Most of the species new to the Chernihiv Polissia have a wide range of distribution – 15 of them. There were species with European range type: Lepthyphantes minutus, Trichoncus affinis, Typhochrestus digitatus and Titanoeca spominima. The European-ancient Mediterranean habitat type is characteristic of 4 more species: Alopecosa cursor, Lathys humilis, Drassyllus praeficus and Ozyptila scabricula. European-Caucasian species: Asagena meridionalis and Gibbaranea gibbosa. With the Scythian type range of Alopecosa taeniopus. The fact of the coexistence of Pisaura novicia and P. mirabilis, which was previously described by other authors, was confirmed. Five species: Hahnia nava, Centromerus incilium, Sintula spiniger, Stemonyphantes lineatus and Trochosa terricola were found in all three types of biotopes investigated. The Jacquard index of faunal similarity showed a slight similarity of the species complexes of spiders of the pine forest and the psammophilic grassland habitat – 0.23, and the value of the Shannon index for both was identical – 4.277 bits, indicating a potentially high level of species richness of the spider fauna of the Bykivnian forest area.
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Schrumpf, M., K. Kaiser, G. Guggenberger, T. Persson, I. Kögel-Knabner i E. D. Schulze. "Storage and stability of organic carbon in soils as related to depth, occlusion within aggregates, and attachment to minerals". Biogeosciences 10, nr 3 (13.03.2013): 1675–91. http://dx.doi.org/10.5194/bg-10-1675-2013.
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Abstract. Conceptual models suggest that stability of organic carbon (OC) in soil depends on the source of plant litter, occlusion within aggregates, incorporation in organo-mineral complexes, and location within the soil profile. Density fractionation is a useful tool to study the relevance of OC stabilization in aggregates and in association with minerals, but it has rarely been applied to full soil profiles. We aim to determine factors shaping the depth profiles of physically unprotected and mineral associated OC and test their relevance for OC stability across a range of European soils that vary in vegetation, soil types, parent material, and land use. At each of the 12 study sites, 10 soil cores were sampled to 60 cm depth and subjected to density separation. Bulk soil samples and density fractions (free light fractions – fLF, occluded light fractions – oLF, heavy fractions – HF) were analysed for OC, total nitrogen (TN), δ14C, and Δ14C. Bulk samples were also incubated to determine CO2 evolution per g OC in the samples (specific mineralization rates) as an indicator for OC stability. Depth profiles of OC in the light fraction (LF-OC) matched those of roots for undisturbed grassland and forest sites, suggesting that roots are shaping the depth distribution of LF-OC. Organic C in the HF declined less with soil depth than LF-OC and roots, especially at grassland sites. The decrease in Δ14C (increase in age) of HF-OC with soil depth was related to soil pH as well as to dissolved OC fluxes. This indicates that dissolved OC translocation contributes to the formation of subsoil HF-OC and shapes the Δ14C profiles. The LF at three sites were rather depleted in 14C, indicating the presence of fossil material such as coal and lignite, probably inherited from the parent material. At the other sites, modern Δ14C signatures and positive correlations between specific mineralization rates and fLF-OC indicate the fLF is a potentially available energy and nutrient source for subsurface microorganisms throughout the profile. Declining specific mineralization rates with soil depth confirm greater stability of OC in subsoils across sites. The overall importance of OC stabilization by binding to minerals was demonstrated by declining specific mineralization rates with increasing contributions of HF-OC to bulk soil OC, and the low Δ14C values of HF-OC. The stability of HF-OC was greater in subsoils than in topsoils; nevertheless, a portion of HF-OC was active throughout the profile. While quantitatively less important than OC in the HF, consistent older ages of oLF-OC than fLF-OC suggest that occlusion of LF-OC in aggregates also contributes to OC stability in subsoils. Overall, our results indicate that association with minerals is the most important factor in stabilization of OC in soils, irrespective of vegetation, soil type, and land use.
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Demydenko, O., i V. Velichko. "Microagrogenesis of chernozem in agrocenosis". Agricultural Science and Practice 4, nr 1 (15.04.2017): 28–45. http://dx.doi.org/10.15407/agrisp4.01.028.
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The aim of the study was to provide scientifi c and theoretical substantiation for the process of microaggrega- tion of typical chernozem via the simulation of natural processes of soil formation under the effect of systemat- ic application of soil-protecting technologies of crop cultivation with surface packing of root and after-harvest remains, humus, and mineral fertilizers in agrocenoses of the Left-Bank Forest-Steppe of Ukraine. Methods. Laboratory-analytical, experimental fi eld, statistical. Results. During tillage (for over 75 years) the number of free and friable-linked aggregates in the 0–40-cm chernozem layer decreased down to 17–20 %, and on the background of organic-mineral system of fertilization (15 t/ha of humus + N 80 P 75 K 60 ) there was an increase in the content of the mentioned groups of microaggregates up to 20–25 %. The systematic implementation of soil protective technologies promoted the increase in the content of free and friable-linked microaggregates up to 29–32 %. During tillage, the coeffi cient of saturation with humus for physical clay (PC) decreased 1.3–1.4 times compared to the grassland. The value of PC saturation during the soil protective tillage was optimal, as humus was neither accumulated in the form of free humates, nor stored like “fat” in animal organisms.aAnd there was no blocking of nutrients with free humates. Humus acts as a connective tissue, promoting the improved water-resistance of chernozem structure on the micro- and macroaggregate levels. The ability of chernozems to have aggregation was determined by the dispersion factor (DF), which was 12–14 % during tillage without introducing any fertilizers, and 10 % – with the introduction of fertilizers, which testifi ed to a weak degree of microaggregation. With minimal tillage on the background of the organo-mineral system of fertilization, DF = = 6–7 %, and by the end of rotation it decreased down to 3-5 %. Conclusions. Enhanced microaggregation in soil protective technologies is explained by the fact that detritus and newly formed humic substances enhance their role in the formation of organo-mineral complexes in case of optimization of hydrothermal conditions in the seasonal cycle and decreased tempo of humus mineralization. The correlation coeffi cient between the num- ber of microaggregates, sized 0.01–0.25 mm and the content of peptized humic substances during tillage was as follows: R = +0.480.01, and for soil protective technologies it was: R = (+0.70–0.75) 0.01. The increase in microaggregation in conditions of soil protective tillage occurred in the direction of wild land analogs and fallow, which testifi ed to the simulation of the natural process of typical chernozem microaggregation in the agrocenoses of the Left-Bank Forest-Steppe of Ukraine.
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Huygens, D., P. Boeckx, O. Van Cleemput, C. Oyarzún i R. Godoy. "Aggregate and soil organic carbon dynamics in South Chilean Andisols". Biogeosciences 2, nr 2 (24.06.2005): 159–74. http://dx.doi.org/10.5194/bg-2-159-2005.
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Abstract. Extreme sensitivity of soil organic carbon (SOC) to climate and land use change warrants further research in different terrestrial ecosystems. The aim of this study was to investigate the link between aggregate and SOC dynamics in a chronosequence of three different land uses of a south Chilean Andisol: a second growth Nothofagus obliqua forest (SGFOR), a grassland (GRASS) and a Pinus radiata plantation (PINUS). Total carbon content of the 0-10cm soil layer was higher for GRASS (6.7 kg C m-2) than for PINUS (4.3 kg C m-2, while TC content of SGFOR (5.8 kg C m-2) was not significantly different from either one. High extractable oxalate and pyrophosphate Al concentrations (varying from 20.3-24.4 g kg-1, and 3.9-11.1 g kg-1, respectively) were found in all sites. In this study, SOC and aggregate dynamics were studied using size and density fractionation experiments of the SOC, δ13C and total carbon analysis of the different SOC fractions, and C mineralization experiments. The results showed that electrostatic sorption between and among amorphous Al components and clay minerals is mainly responsible for the formation of metal-humus-clay complexes and the stabilization of soil aggregates. The process of ligand exchange between SOC and Al would be of minor importance resulting in the absence of aggregate hierarchy in this soil type. Whole soil C mineralization rate constants were highest for SGFOR and PINUS, followed by GRASS (respectively 0.495, 0.266 and 0.196 g CO2-Cm-2d-1 for the top soil layer). In contrast, incubation experiments of isolated macro organic matter fractions gave opposite results, showing that the recalcitrance of the SOC decreased in another order: PINUS>SGFOR>GRASS. We deduced that electrostatic sorption processes and physical protection of SOC in soil aggregates were the main processes determining SOC stabilization. As a result, high aggregate carbon concentrations, varying from 148 till 48 g kg-1, were encountered for all land use sites. Al availability and electrostatic charges are dependent on pH, resulting in an important influence of soil pH on aggregate stability. Recalcitrance of the SOC did not appear to largely affect SOC stabilization. Statistical correlations between extractable amorphous Al contents, aggregate stability and C mineralization rate constants were encountered, supporting this hypothesis. Land use changes affected SOC dynamics and aggregate stability by modifying soil pH (and thus electrostatic charges and available Al content), root SOC input and management practices (such as ploughing and accompanying drying of the soil).
Rozprawy doktorskie na temat "Grassland-forest complexes"
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Jambhekar, Ravi Madhav. "The influence of landscape composition on butterfly populations: A behavioural ecological approach". Thesis, 2019. https://etd.iisc.ac.in/handle/2005/4828.
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Overall, taking behavioural ecological and trait-based approaches, my study suggests that the distribution of a species and patterns in its population densities in a landscape are affected by diverse ecological variables, including local factors, such as heterogeneity in multiple resources required by a species, and landscape factors, such as habitat area and connectivity. Using a behavioural ecological approach, I find that butterflies responded to resource heterogeneity at multiple spatial scales and appeared to balance acquiring multiple resources when making foraging and space-use decision. The next step would be to examine how such foraging and space use decisions influence demographic parameters, such as survival, fecundity and movement, and thereby affect the dynamics of butterfly populations. Next, examining landscape-level factors using trait-based approaches, my study highlights that species responses to landscape features can be strikingly variable, for example with some species showing strong negative relationships and others no consistent relationship with connectivity. Similarly, I also found striking variation in species distributions in the landscape. Interestingly, varied functional traits (ecological, morphological, life-history, and behavioural) helped predict these diverse responses to landscape features, and the diverse species distributions. My findings suggest that strength of habitat associations at small and large spatial scales, matrix permeability, wing span, diet breadth and flight characteristics are important traits in butterflies that can be used build a predictive framework for how butterfly populations respond to landscape structure and composition. How these individual population responses to local and landscape features translate into community-level processes needs to be investigated.
Części książek na temat "Grassland-forest complexes"
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Parton, William J., i Stephen J. Del Grosso. "The Shortgrass Steppe and Ecosystem Modeling". W Ecology of the Shortgrass Steppe. Oxford University Press, 2008. http://dx.doi.org/10.1093/oso/9780195135824.003.0019.
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Ecological modeling has played a key role in scientific investigations of the SGS LTER during the past several decades. The SGS LTER site, focused initially on the Central Plains Experimental Range (CPER), was the main grassland research site for the Grassland Biome component of the U.S. IBP effort (Lauenroth et al., this volume, chapter 1). Initial development of ecosystem models occurred from 1 970 to 1 975 as p art of t he I BP . All the U.S. I BP projects (grassland, tundra, desert, deciduous forest, and coniferous forest biomes) included research on the development of ecosystem models, with the goals of using models to help formulate and interpret field experiments, and of projecting the impact of changes in management practices on ecosystem dynamics. Models were developed as part of the Grassland Biome project (Bledsoe et al., 1971; Innis, 1978), and included modeling specialists who worked with research biologists on the development and formulation of the ecosystem models. The modeling activities of t he U.S. IBP Grassland Biome project included developing the ELM Grassland model (Innis, 1978). The ELM model was a complex process-oriented model that was intended to be used at all the Grassland Biome sites in the United States. This model was developed by postdoctoral fellows who were to formulate the different submodels, and then link the submodels using software that was developed as part of the program. The submodels included a plant production submodel, a cattle production submodel, a linked nutrient cycling and soil organic matter submodel, a grasshopper dynamics submodel, and a soil temperature and water submodel. Biophysical and biological data from the different sites were collected to develop and test the model. Model development was constrained by lack of knowledge about the biological processes that control ecosystem behavior, and by lack of appropriate data to test the ability of the model to simulate ecosystem responses to changes in grazing and fertility management practices. However, the ELM Grassland model was quite successful at investigating the interactions of different components of the ecosystem, and at helping to formulate new research efforts.
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Greenland, David, i Douglas G. Goodin. "Introductory Overview". W Climate Variability and Ecosystem Response in Long-Term Ecological Research Sites. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195150599.003.0036.
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The timescale structure of this book has served well to keep the attention of investigators focused on specific aspects of climate variability and ecosystem response. Indeed, judging by the responses received by the editors of this volume, when given a choice between focusing on one timescale or several timescales, the LTER community was far more comfortable dealing with just one scale. There are obvious reasons for this, not the least of which is that focusing on a single scale greatly simplifies things. The real world, however, does not focus on one timescale. Climatic events and ecosystem responses occur simultaneously at a variety of scales. We wished to explore the climatic variability and ecosystem responses at LTER sites across several different timescales, and the two chapters in this part attempt such an exploration. The chapters consider the temperate rainforest of the H. J. Andrews LTER site in Oregon and the tallgrass ecosystem of the Konza Prairie LTER in Kansas. For the Andrews rainforest, and to some extent the Pacific Northwest (PNW) in general, Greenland et al. (chapter 19) discuss climate variability and ecosystem response at the daily, multidecadal, and century to millennial scales. This discussion for the PNW is supplemented in chapters 6 and 13 of this volume by a consideration of the quasi-quintennial scale and an additional ecosystem response at the decadal scale. The forest ecosystem is more complex than the grassland ecosystem. Greenland et al. cover a wide variety of potential ecosystem responses for the PNW Forest, ranging from severe weather events, to pine cone production, to century- and millennial-scale forest fire frequency regimes and their variation. The focus of chapter 19 is on some of the framework questions of this volume. The questions specifically addressed include the following: What preexisting conditions affect the impact of the climatic event or episode? Is the climatic effect on the ecosystems direct or cascading? Does the system return to its original state? The authors also consider potential future climate change and its possible ecosystem effects. They found that timescale becomes important in addressing some of these questions. For example, at century to millennial timescales, it is suggested that there are likely to be no identical past analogs to the ecosystem at any point in time.
Streszczenia konferencji na temat "Grassland-forest complexes"
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Yaroshenko, Nataliia, i Viktoriia Skliar. "ONTHOGENETIC AND VITALITY STRUCTURE OF ASARUM EUROPAEUM IN TERMS OF FOREST MANAGEMENT IN GOETTINGEN FOREST, LOW SAXONY, GERMANY". W 22nd International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022v/3.2/s14.46.
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A detailed study of the herb layer species of forest ecosystems that are anthropogenically affected makes it possible to predict the successive changes and model the development of plant communities in particular areas. The study results of grassland species populations contribute to the restoration and preservation of unique groups that are part of forest ecosystems. Our research deals with understanding the mechanisms of adaptations that exist at the population level of the organization against the background of forestry impacts. With the comprehensive population analysis approach, the critical point is to observe the consequences after the transformation of the living conditions of plants. The research aim is to establish features and regularities of structural changes in the population typical for beech forests in Low Saxony, Germany, in terms of forestry use. Our research is based on the classical geobotanical and population analysis methods. We used morphometric, vital, gradient analyses, and mathematical statistics methods to process field research materials. It is curtained that the vitality determining features for A. europeaum were W - complete plant phytomass, Wl - leaves phytomass, and A � total foliage surface area. It was found that a significant part of the early generative ontogenetic stage of the Asarum europaeum population is represented in the unmanaged forest. In contrast, in the young forest plots of 40 and 70 years old tree species, the central part is devoted to the middle-aged and old generative ontogenetic stages, 31,25% and 34,33%, respectively. The vitality structure analysis investigated that herb layer species' vitality is remarkably higher in unmanaged forest.