Search results for "Ecological model"

Current Status of and Threats to Sicilian Turtles

2022

Based on the critical review of the literature published in the last 22 years, an attempt was made to evaluate the current knowledge gap on the distribution and status of the native Testudines taxa occurring in Sicily (namely Caretta caretta, Emys trinacris, and Testudo hermanni hermanni), as well as the available knowledge of the only non-native species with putative viable populations occurring on the island, i.e., Trachemys scripta. Summarizing the current information, all of the Testudines species occurring in Sicily showed a fragmented and incompletely-known distribution, and only scarce data are available about their phenology. Moreover, despite their inclusion of international and na…

A numerical model of the cloud-topped planetary boundary-layer: radiative forcing of aerosols in stratiform clouds

1998

In a numerical sensitivity study with the microphysical stratus model MISTRA the impact of aerosol particles on the time evolution of stratiform clouds is investigated. Four model runs with different aerosol size distributions are presented. Two size distributions are typical for maritime and continental air masses. The third model run consists of a mixture of maritime and rural aerosol particles, while in the fourth case study rural aerosol particles with a reduced water solubility are utilized. The numerical results show that the microphysical structure of the clouds is strongly affected by the physico-chemical properties of the aerosol particles. In the maritime case, with a relatively l…

The spatial pattern of a forest ecosystem

1998

Abstract Statistical analysis of stands of trees as a whole need suitable methods of spatial statistics. Obviously, trees within a stand affect development and survival of their neighbours. They interact and therefore have to be considered as a system of dependent random variates from an unknown stochastic process. One such statistical model which considers the spatial dependence among trees in a forest and their characteristics is a marked point process. The `points', called events in spatial statistics, are the tree positions and the `marks' are tree characteristics such as crown lengths or tree species. A minimal prerequisite for any serious attempt to model an observed pattern is to tes…

The Economic Impact of Restricted Water Supply: a Computable General Equilibrium Analysis

2007

Water problems are typically studied at the level of the river catchment. About 70% of all water is used for agriculture, and agricultural products are traded internationally. A full understanding of water use is impossible without understanding the international market for food and related products, such as textiles. The water embedded in commodities is called virtual water. Based on a general equilibrium model, we offer a method for investigating the role of water resources and water scarcity in the context of international trade. We run five alternative scenarios, analyzing the effects of water scarcity due to reduced availability of groundwater. This can be a consequence of physical con…

Network measures in animal social network analysis : Their strengths, limits, interpretations and uses

2020

International audience; We provide an overview of the most commonly used social network measures in animal research for static networks or time‐aggregated networks. For each of these measures, we provide clear explanations as to what they measure, we describe their respective variants, we underline the necessity to consider these variants according to the research question addressed, and we indicate considerations that have not been taken so far. We provide a guideline indicating how to use them depending on the data collection protocol, the social system studied and the research question addressed. Finally, we inform about the existent gaps and remaining challenges in the use of several va…

Assessment of ecosystem integrity and service gradients across Europe using the LTER Europe network

2015

Better integration of knowledge from ecological, social and economic science is necessary to advance the understanding and modelling of socio-ecological systems. To model ecosystem integrity (EI) and ecosystem services (ES) at the landscape scale, assessment matrices are commonly used. These matrices assign capacities to provide different services to different land cover types. We revised such an existing matrix and examined the regional heterogeneity in EI and ES provision in Europe and searched for spatial gradients in their provision to elucidate their suitability for large-scale EI and ES mapping in Europe. Overall, 28 sites belonging to the Long-Term Ecological Research network in Euro…

The possibilities of using broadleaf cattail seeds (Typha latifolia L.) as super absorbents for removing aromatic hydrocarbons (BTEX) from an aqueous…

2018

Sorption of oil-related products (including mainly the propellants) is the very basic process that counteracts spreading these types of pollution into environment. Plenty of synthetic substances (including the monoaromatic hydrocarbons) are both from the surface and underground waters. The aim of this study was to present the research’s results on the possibilities of using the broadleaf cattail (Typha latifolia L.) seeds as a sorbent of monoaromatic hydrocarbons from an aqueous solution. In order to increase sorptive capacity, the seeds biomass was submitted for the process of mercerizing in diversified time and temperature in water and the NaOH solution. The removal of benzene, toluene, e…

Spatial and temporal changes in Actinobacterial dominance in experimental artificial groundwater recharge.

2008

Abstract Artificial groundwater recharge (AGR) is used in the drinking water industry to supplement groundwater resources and to minimise the use of chemicals in water treatment. This study analysed the spatial and temporal changes of microbial communities in AGR using two test systems: a nutrient-amended fluidized-bed reactor (FBR) and a sand column. Structural changes in the feed lake water (Lake Roine), FBR, and sand column bacterial communities were determined by denaturing gradient gel electrophoresis (DGGE) and the length heterogeneity analysis of amplified 16S rRNA genes (LH-PCR). Two clone libraries were created to link the LH-PCR results to the dominant bacterial groups. The lake w…

Microbial diversity in a thermophilic aerobic biofilm process: analysis by length heterogeneity PCR (LH-PCR).

2003

A two-stage pilot-scale thermophilic aerobic suspended carrier biofilm process (SCBP) was set up for the on-site treatment of pulp and paper mill whitewater lining. The microbial diversity in this process was analyzed by length heterogeneity analysis of PCR-amplified 16S ribosomal DNA. The primer pair selected for PCR amplification was first evaluated by a computational analysis of fragment lengths in ten main phylogenetical eubacterial groups. The fragment contained the first third of the 16S rRNA gene, which was shown to vary naturally between 465 and 563 bp in length. The length heterogeneity analysis of polymerase chain reaction (LH-PCR) profile of the biomass attached to carrier elemen…

2015

Abstract. Long term meteorological records (> 100 years) from stations associated with villages are generally classified as rural and assumed to have no urban influence. Using networks installed in two European villages, the local and microclimatic variations around two of these rural-village sites are examined. An annual average temperature difference ($\\Delta{T}$) of 0.6 and 0.4 K was observed between the built-up village area and the current meteorological station in Geisenheim (Germany) and Haparanda (Sweden), respectively. Considerably larger values were recorded for the minimum temperatures and during summer. The spatial variations in temperature within the villages are of the sam…