The Effects of Large Herbivores on Soil Organic Matter Quality in Terrestrial Ecosystems

Understanding the factors that control the natural fluxes of carbon into and out of terrestrial ecosystems is of paramount importance to forecast and adapt to climate change. Soil respiration – the release of carbon dioxide from roots and soil micro-organisms– is considered to be the largest terrestrial source of carbon dioxide. Microbial respiration, the least understood component of soil respiration, is to a great extent determined by soil organic matter quality, reflecting the relative fractions of labile and recalcitrant soil carbon. The goal of this research was to examine how herbivory affects soil organic matter quality across a wide range of terrestrial ecosystems, including Oregon sagebrush steppe, Colorado short grass prairie, Nebraska mixed-grass prairie, Kansas tall grass prairie, and boreal forests in Isle Royale National Park (Michigan) and Acadia National Park (Maine). Studying the effects of herbivores on soil organic matter quality among such a wide variety of ecosystems has not been previously undertaken. Soil organic matter quality was determined with a long-term, 36-week laboratory incubation experiment on soils collected from paired plots located outside and inside long-term exclosures in each of the ecosystems. For the sagebrush steppe, soils were sampled separately beneath shrubs and interspace because of previous reports of large effects of shrubs on soil properties. Herbivory had varying effects (positive, negative, and neutral) on soil organic matter quality at the sites. Herbivory increased soil organic matter quality at the shortgrass prairie, tallgrass prairie, and Isle Royale boreal forest, and reduced it at one of two boreal forests in Acadia and under shrubs in the sagebrush steppe. Herbivory had no effect on the mixed-grass prairie, one of two boreal forests in Acadia, and under interspace in the sagebrush steppe. The variable effects of herbivores may have been a function of the particular responses of plant species to herbivory among ecosystems and/or potential confounding differences in soil properties between paired plots. Future work should include experiments that investigate how herbivores impact linked plant and soil dynamics of grassland and forest ecosystems. The major implication of these findings is that policy makers will need to develop herbivore management policies on an ecosystem-by-ecosystem basis if they hope to manage soil organic matter quality to maximize soil carbon sequestration

Mammalian turnover as an indicator of climatic and anthropogenic landscape modification: A new Meghalayan record (Late Holocene) in northern Iberia

Acknowledgements AB.M-A. developed part of this research as part of the ERC Consoli- dator Grant (SUBSILIENCE ref. 818299). We thank J.A. Delgado for his technical work on studying macromammal assemblage. Financial sup- port was provided by the Bilbao Port Authority (Autoridad Portuaria de Bilbao) within the project “Estabilizaci´on del sector occidental de la Cantera de Punta Lucero en el Puerto de Bilbao”. We are also grateful to Juan Manuel L´opez-García and the anonymous reviewer for their sug- gestions and comments that strongly improved the manuscript.Supplementary data to this article can be found online at https://doi.org/10.1016/j.palaeo.2023.111476The Punta Lucero III cave is a natural trap where abundant vertebrate remains were accumulated during the Meghalayan (Late Holocene). To better understand the paleoenvironmental conditions in which this record was accumulated, the micromammal assemblage, comprising a minimum number of 1396 individuals belonging to 19 taxa, was studied using the Mutual Ecogeographic Range and the Habitat Weighting Method. Throughout ~2600 years, the micromammal community's quick turnover reflected a shift from patchy forests and humid meadows to open, shrubbier grasslands. The Late Holocene Thermal Maximum's humid and mild climatic conditions underwent a cooling and aridification phase, coeval with the Iron Age Cold Epoch. These concluded in a slight temperature rising, coeval with the Roman Warm Period. Macromammals experienced a shift from wild populations to domestic herds. Therefore, this work discusses a broader context for this mammalian turnover from a human cultural perspectiveERC Consolidator Grant (SUBSILIENCE ref. 818299)Bilbao Port Authority (Autoridad Portuaria de Bilbao)Estabilización del sector occidental de la Cantera de Punta Lucero en el Puerto de Bilba

Information-driven persistent sensing of a non-cooperative mobile target using UAVs

This paper addresses the persistent sensing problem of moving ground targets of interest using a group of fixed wing UAVs. Especially, we aim to overcome the challenge of physical obscuration in complex mission environments. To this end, the persistent sensing problem is formulated under an optimal control framework, i.e. deploying and managing UAVs in a way maximising the visibility to the non-cooperative target.The main issue with such a persistent sensing problem is that it generally requires the knowledge of future target positions, which is uncertain. To mitigate this issue, a probabilistic map of the future target position is widely utilised. However, most of the probabilistic models use only limited information of the target. This paper proposes an innovative framework that can make the best use of all available information, not only limited information. For the validation of the feasibility, the performance of the proposed framework is tested in a Manhattan-type controlled urban environment. All the simulation tests use the same framework proposed, but utilise different level of information. The simulation results confirm that the performance of the persistent sensing significantly improves, up to 30%, when incorporating all available target information

O PENSAMENTO COMPLEXO EM EDGAR MORIN - CONSIDERAÇÕES INICIAIS

Este texto tem por objetivo apresentar alguns pressupostos dopensamento de Edgar Morin, sobretudo no que se refere a suaconcepção de complexidade, evidenciando alguns aspectos referentes à educação

Design, Simulation and Thermo-Economic Assessment of a Transcritical Carbon Dioxide Solar Power Plant for Medium-Scale Electricity and Heat Generation

This project comprises the engineering design and assessment of the novel above critical-point Carbon Dioxide cycle technology integrated with a solar Parabolic Trough Collector (PTC) plant. To accomplish this, preliminary studies were first performed on initial simple calculations of the thermodynamics of the different CO2 cycles and solar energy technology. Knowledge was also acquired through an ongoing literature review. A design model was then developed in EES, to assist in the design of the different systems of the power plant including the solar field, power block and components such as turbomachines and heat exchangers. Another model was developed in EES to simulate for average and median days for each month in the year by inputting a meteorological TMY3 data set and obtaining performance results. Pre-processing of data inputs and post-processing of outputs was done with MATLAB, as well as the understanding of the meteorological design conditions of the location chosen for the analysis, which is College Station, TX. Next, the results were confirmed with more advanced simulation software, namely SAM, provided by NREL. A one 1-MW facility with a simple transcritical CO2 cycle, which also provided cogeneration heat for a small industry (case A), was proposed as a baseline plant. Other alternatives studied were: a 10-MW facility for University Campus Utilities (case B), a 1-MW plant with a Recompression CO2 cycle (case C), and finally a 1-MW plant with a supercritical CO2 cycle (case D). Results obtained for the baseline plant show an LCOE of $0.2915/kWh while lowest LCOE obtained was the one for alternative B:$0.2613/kWh. Although it was concluded that this technology not in position to make a market penetration, a sensitivity analysis was performed revealing important clues as to how the energy cost could be reduced so as to make it more viable in the future

Burocracia e educação: considerações preliminares

A presente pesquisa é parte integrante do projeto de pesquisa “Organização Burocrática e Gestão Escolar: a perspectiva dos diretores escolares da Rede Municipal de Ensino de Cascavel”1. Tem por objetivo apresentar um panorama acerca dos estudos e pesquisas sobre as organizações burocráticas, evidenciando suas principais vertentes de análise. Procura identificar suas principais matrizes teóricas, em Hegel e Weber, e as análises posteriores contemporâneas, como as de Bresser Pereira e Prestes Motta. Procura analisar, também, a influência dos estudos organizacionais no âmbito das organizações educativas. 1 Projeto de Pesquisa em andamento, realizado com financiamento da Fundação Araucária (auxílio financeiro e concessão de bolsas de Iniciação Científica)