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The impact of diversity on global leadership performanceStorey, Sylvana Clare January 2013 (has links)
Purpose: The focus of this research is to understand the impact of diversity on global leadership performance. Design/methodology/approach: From the literature review the researcher developed the components of the LEAD³ tool as well as, devised the questions for the in-depth semi-structured interviews that would test the tool. The questions centred on the three constructs of leadership, diversity and organisational factors and interviews were conducted between 2009 and 2010. The sample consisted of 79 senior leaders from seven companies across seven differing sectors and covered 22 different countries across 5 continents. A case study research strategy using a hybrid of open coding, thematic analysis and content analysis was employed. Findings: A series of themes were found under the three constructs: For Global leadership – competencies, connecting, rigour, stakeholder satisfaction, value based professional, influences. For Diversity – inclusivity, performance measures, role modelling, positioning diversity and innovation. For Organisational factors – organisational way of being, facilitating diversity, behavioural practices, ways of working, issues of concern and driving diversity. Issues emerging from the comparative analysis consist of cultural dimensions, engagement and learning. Research Limitations: Issues on reliability and validation, translation in measurement, environmental inconsistency, interviewer/interviewee bias, and ecological fallacy often levied at qualitative research. Research Contribution and Value: The findings tested against the tool, confirm the robustness and relevancy of the LEAD³ as an operational tool that will enable leaders to focus and integrate their diversity efforts. LEAD³ is encapsulated within an integrated change management framework and proposes a multi-level and multi-dimensional approach to global leadership and diversity that also includes performance drivers, stakeholder groupings, performance outcomes and organisational activities (change interventions). Future Research:Finally, an attempt is made to develop a competency framework for leadership and diversity from data emerging from findings. This is named the Global Leader Index for Diversity (GLIDE) – a framework that recognises the diverse aspects of a global leader’s role and identifies associated skills and behaviours that global leaders of the future need to develop.
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Structure, Productivity and Carbon Storage of Primeval European Beech ForestsGlatthorn, Jonas 08 June 2017 (has links)
No description available.
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ASSEMBLY OF ARTHROPOD COMMUNITIES IN RESTORED PRAIRIE, OLD FIELD AND MONOSPECIFIC STAND OF PHALARIS ARUNDINACEA: A FUNCTIONAL PERSPECTIVEEric M Kelleher (6642413) 11 June 2019 (has links)
<p>Effects of prairie restoration on arthropod diversity was investigated
at Gabis Arboretum, Valparaiso, Indiana. A total of
35,408 arthropods belonging to 13 taxa in the restored prairie (RP1 and RP2), old field (OF), and monoculture stand of Phalaris
arundinacea (reed canary grass – RCG) sites, were captured, counted, and compared. The enhanced plant species diversity in the restored prairies did not appear to promote the diversity of
arthropod taxa. However, the restoration led to a more balanced composition of arthropod functional
groups and thus elevated the diversity of functional groups.
The arthropod assemblages in the three sites diverged clearly according to my canonical correspondence analysis (CCA)
ordination. Pollinator abundance was greatest at RP and least at RCG site, positively correlating with
greater forb diversity, and suggesting greater potential for nectar feeding and pollination
potential at RP sites. Herbivore abundance was greatest at the RP sites, positively correlating with
increasing plant species diversity. Predator abundance
was significantly greater at the RCG site compared to the OF and RP sites; it was positively correlated with greater C3 grass cover, a
characteristic of the structurally homogenous RCG site, and negatively correlated with
increasing plant diversity and forb cover, a characteristic of the diverse and more structurally
complex RP sites. Given the apparent non-random distribution of arthropods among the field types,
my results suggest plant species composition has a significant effect on arthropod
assembly. The monoculture grass stand was found to have a predator dominated arthropod community supported by
a small, diverse herbivore community. It is
concluded that the prairie restoration has resulted in alteration of arthropod communities supporting greater pollinator and herbivore
abundance and a more balanced ratio of herbivores to predators due, in part, to increased
plant structural diversity.</p>
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Indicadores microbiológicos de qualidade do solo em Florestas de Araucária no Estado de São Paulo / Microbilogical indicators of soil quality in Araucaria Forest in São Paulo StateSimone Cristina Braga Bertini 14 February 2011 (has links)
A Araucaria angustifolia, conhecida como Pinheiro-do-Paraná é uma espécie ameaçada de extinção no Brasil, está inserida num bioma rico em biodiversidade, a Mata Atlântica, e muito pouco se conhece sobre os atributos microbiológicos dessas florestas. Este trabalho teve como objetivo avaliar potenciais atributos microbiológicos do solo e algumas variáveis ambientais (atributos químicos, físicos e efeito sazonal), a fim de estabelecer bioindicadores de qualidade do solo em Florestas de Araucária. Os estudos foram conduzidos em dois parques estaduais localizados em diferentes regiões do Estado de São Paulo, no município de Campos do Jordão (Parque Estadual de Campos do Jordão - PECJ), nos municípios de Apiaí e Iporanga (Parque Estadual Turístico do Alto Ribeira - PETAR) e também no município de Barra do Chapéu. Foram escolhidas três áreas no PETAR: FN floresta nativa de araucária, ND floresta de araucária com distúrbio antropogênico e PL plantio de araucária; e quatro áreas foram selecionadas no PECJ: FN floresta nativa de araucária, ND floresta de araucária com distúrbio antropogênico, PL plantio de araucária e PF plantio de araucária com ocorrência de fogo acidental. Ao acaso, foram selecionadas quinze árvores de araucária por área e sob a copa de cada uma delas foram retiradas amostras na profundidade de 0 a 20 cm, nas épocas seca e de chuva. Foram avaliados os atributos microbiológicos: arilsulfatase (ARIL), fosfatase ácida (FOSF), -glicosidase (GLIC), desidrogenase (DESID), nitrogênio (NBM) e carbono da biomassa microbiana (CBM), Número Mais Provável (NMP) de amonificantes (AMO), nitritadores (NITRI), nitratadores (NITRA) e desnitrificantes (DESN), respiração basal (RESP), respiração induzida por substrato (RIS), quociente metabólico (qCO2) e microbiano (qMIC). Além disso, foram estabelecidos perfis de ácidos graxos ligados a ésteres de fosfolipídios (EL-PLFAs) e o perfil de capacidade de utilização de substratos de carbono (Biolog). Alguns parâmetros químicos foram avaliados (pH, H++Al3+, Al3+, Ca2+, Mg2+, K+, P, S, N, carbono orgânico total e a capacidade de troca catiônica) e físicos (teores de argila, silte e areia). Verificou-se que o PL do PETAR e PF do PECJ foram relacionados aos atributos microbiológicos ARIL, DESN, CBM e qMIC nos dois períodos. A partição da variabilidade revelou que a atividade microbiana foi influenciada mais pelas variáveis físico-quimicas do solo do que pelas áreas e épocas de coleta. Foram identificados perfis de ácidos graxos semelhantes aos aqui obtidos, PETAR e PECJ, em um trabalho anterior no PECJ, o que pode ser indicação de um padrão de EL-PLFA próprio do ecossistema de araucária. Os ácidos graxos 10Me18:0 (actinobactéria), a relação ácido graxo saturado/insaturado (sat/insat), o consumo dos substratos -metil-D-glicosídeo e o ácido 2-hidroxibenzóico foram também relacionados às áreas PL (PETAR) e PF (PECJ) nos períodos avaliados. Já os ácidos graxos 18:19c (fungo) e 16:17c (bactéria Gram-), o consumo dos substratos glicose-1-fosfato, -D-lactose e ácido -hidroxibutírico estavam relacionados às áreas impactadas dos dois parques durante os períodos de seca e chuva. Portanto, esses atributos microbiológicos são potenciais indicadores de qualidade do solo em Florestas de Araucária, no entanto, novas avaliações são necessárias para as devidas validações dos bioindicadores e monitoramento dessas áreas. / Araucaria angustifolia, also called Brazil Pine, is an endangered species in Brazil. It is part of one of the richest ecosystems in biodiversity, the Atlantic Forest, and little is known about the soil microbiological attributes in this forest. The objective was to evaluate the potential of the soil microbiological attributes and some environmental variables (physical-chemical properties and seasonal effect) to act as bioindicators of soil quality in Araucaria Forests. This study was undertaken in two different state parks in the São Paulo State, in Campos do Jordão county (Campos do Jordão State Park - PECJ), and in Apiaí and Iporanga counties (Alto Ribeira Touristic State Park - PETAR) and also in Barra do Chapéu county. Three areas were surveyed in PETAR: FN Native Araucaria forest, ND Native Araucaria forest with anthropogenic disturbance, and PL Reforested Araucaria; and four areas in PECJ: FN Native Araucaria forest, ND Native Araucaria forest with anthropogenic disturbance; PL Reforested Araucaria, and PF Araucaria reforestation submitted to an accidental fire. Fifteen Araucaria trees were selected at random in each area and the soil and roots were sampled at 0 20 cm depth, in two contrasting seasons (dry and wet). The microbiological attributes evaluated were: arylsulfatase (ARIL), acid phosphatase (FOSF), -glucosidase (GLIC), dehydrogenase (DESID), carbon (CBM) and nitrogen microbial biomass (NBM), most probable number (NMP) of bacterial ammonium oxidizers (AMO), nitrite oxidizers (NITRI), nitrate oxidizers (NITRA) and denitrifiers (DESN), basal microbial respiration (RESP), substrate induced respiration (RIS), and metabolic (qCO2) and microbial quotient (qMIC). Additionally we determined the phospholipid fatty acid profiles (ELPLFA) and the community level physiological profile (Biolog). Some chemical attributes were evaluated (pH, H++Al3+, Al3+, Ca2+, Mg2+, K+, P, S, CEC, C/N ratio, total organic carbon (COT), total nitrogen (NT), as well as some physical ones (soil texture: clay, sand and silt contents). There was a high correlation between the PL of PETAR and the PF of PECJ and the microbiological attributes ARIL, DESN, CBM and qMIC in both periods. The partitioning of the variability evidenced that microbial activity was influenced in a higher degree by the physical-chemical properties of soil than by study areas or periods. We identified similar fatty acid profiles in PETAR and PECJ and they were also similar to the ones found in a previous work in PECJ, what could indicate a specific EL-PLFA pattern in the Araucaria ecosystem. The fatty acids 10Me18:0 (actinobacteria), the saturated/unsaturated fatty acid ratio (sat/insat), the substrate utilization of -methyl-D-glucoside and 2-hydroxybenzoic acid were also related to PL (PETAR) and PF (PECJ), in both periods. The 18:19c fatty acid (fungi) and 16:17c (Gram-), the glucose-1-phosphate, -D-lactose and -hydroxybutyric acid were C-source for microbial communities of the impacted areas in both parks during the wet and dry periods. Therefore, these attributes are potential microbial indicators of soil quality in Araucaria forests, however, new evaluations are required to confirm these biomarkers and to monitor these areas.
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Indicadores microbiológicos de qualidade do solo em Florestas de Araucária no Estado de São Paulo / Microbilogical indicators of soil quality in Araucaria Forest in São Paulo StateBertini, Simone Cristina Braga 14 February 2011 (has links)
A Araucaria angustifolia, conhecida como Pinheiro-do-Paraná é uma espécie ameaçada de extinção no Brasil, está inserida num bioma rico em biodiversidade, a Mata Atlântica, e muito pouco se conhece sobre os atributos microbiológicos dessas florestas. Este trabalho teve como objetivo avaliar potenciais atributos microbiológicos do solo e algumas variáveis ambientais (atributos químicos, físicos e efeito sazonal), a fim de estabelecer bioindicadores de qualidade do solo em Florestas de Araucária. Os estudos foram conduzidos em dois parques estaduais localizados em diferentes regiões do Estado de São Paulo, no município de Campos do Jordão (Parque Estadual de Campos do Jordão - PECJ), nos municípios de Apiaí e Iporanga (Parque Estadual Turístico do Alto Ribeira - PETAR) e também no município de Barra do Chapéu. Foram escolhidas três áreas no PETAR: FN floresta nativa de araucária, ND floresta de araucária com distúrbio antropogênico e PL plantio de araucária; e quatro áreas foram selecionadas no PECJ: FN floresta nativa de araucária, ND floresta de araucária com distúrbio antropogênico, PL plantio de araucária e PF plantio de araucária com ocorrência de fogo acidental. Ao acaso, foram selecionadas quinze árvores de araucária por área e sob a copa de cada uma delas foram retiradas amostras na profundidade de 0 a 20 cm, nas épocas seca e de chuva. Foram avaliados os atributos microbiológicos: arilsulfatase (ARIL), fosfatase ácida (FOSF), -glicosidase (GLIC), desidrogenase (DESID), nitrogênio (NBM) e carbono da biomassa microbiana (CBM), Número Mais Provável (NMP) de amonificantes (AMO), nitritadores (NITRI), nitratadores (NITRA) e desnitrificantes (DESN), respiração basal (RESP), respiração induzida por substrato (RIS), quociente metabólico (qCO2) e microbiano (qMIC). Além disso, foram estabelecidos perfis de ácidos graxos ligados a ésteres de fosfolipídios (EL-PLFAs) e o perfil de capacidade de utilização de substratos de carbono (Biolog). Alguns parâmetros químicos foram avaliados (pH, H++Al3+, Al3+, Ca2+, Mg2+, K+, P, S, N, carbono orgânico total e a capacidade de troca catiônica) e físicos (teores de argila, silte e areia). Verificou-se que o PL do PETAR e PF do PECJ foram relacionados aos atributos microbiológicos ARIL, DESN, CBM e qMIC nos dois períodos. A partição da variabilidade revelou que a atividade microbiana foi influenciada mais pelas variáveis físico-quimicas do solo do que pelas áreas e épocas de coleta. Foram identificados perfis de ácidos graxos semelhantes aos aqui obtidos, PETAR e PECJ, em um trabalho anterior no PECJ, o que pode ser indicação de um padrão de EL-PLFA próprio do ecossistema de araucária. Os ácidos graxos 10Me18:0 (actinobactéria), a relação ácido graxo saturado/insaturado (sat/insat), o consumo dos substratos -metil-D-glicosídeo e o ácido 2-hidroxibenzóico foram também relacionados às áreas PL (PETAR) e PF (PECJ) nos períodos avaliados. Já os ácidos graxos 18:19c (fungo) e 16:17c (bactéria Gram-), o consumo dos substratos glicose-1-fosfato, -D-lactose e ácido -hidroxibutírico estavam relacionados às áreas impactadas dos dois parques durante os períodos de seca e chuva. Portanto, esses atributos microbiológicos são potenciais indicadores de qualidade do solo em Florestas de Araucária, no entanto, novas avaliações são necessárias para as devidas validações dos bioindicadores e monitoramento dessas áreas. / Araucaria angustifolia, also called Brazil Pine, is an endangered species in Brazil. It is part of one of the richest ecosystems in biodiversity, the Atlantic Forest, and little is known about the soil microbiological attributes in this forest. The objective was to evaluate the potential of the soil microbiological attributes and some environmental variables (physical-chemical properties and seasonal effect) to act as bioindicators of soil quality in Araucaria Forests. This study was undertaken in two different state parks in the São Paulo State, in Campos do Jordão county (Campos do Jordão State Park - PECJ), and in Apiaí and Iporanga counties (Alto Ribeira Touristic State Park - PETAR) and also in Barra do Chapéu county. Three areas were surveyed in PETAR: FN Native Araucaria forest, ND Native Araucaria forest with anthropogenic disturbance, and PL Reforested Araucaria; and four areas in PECJ: FN Native Araucaria forest, ND Native Araucaria forest with anthropogenic disturbance; PL Reforested Araucaria, and PF Araucaria reforestation submitted to an accidental fire. Fifteen Araucaria trees were selected at random in each area and the soil and roots were sampled at 0 20 cm depth, in two contrasting seasons (dry and wet). The microbiological attributes evaluated were: arylsulfatase (ARIL), acid phosphatase (FOSF), -glucosidase (GLIC), dehydrogenase (DESID), carbon (CBM) and nitrogen microbial biomass (NBM), most probable number (NMP) of bacterial ammonium oxidizers (AMO), nitrite oxidizers (NITRI), nitrate oxidizers (NITRA) and denitrifiers (DESN), basal microbial respiration (RESP), substrate induced respiration (RIS), and metabolic (qCO2) and microbial quotient (qMIC). Additionally we determined the phospholipid fatty acid profiles (ELPLFA) and the community level physiological profile (Biolog). Some chemical attributes were evaluated (pH, H++Al3+, Al3+, Ca2+, Mg2+, K+, P, S, CEC, C/N ratio, total organic carbon (COT), total nitrogen (NT), as well as some physical ones (soil texture: clay, sand and silt contents). There was a high correlation between the PL of PETAR and the PF of PECJ and the microbiological attributes ARIL, DESN, CBM and qMIC in both periods. The partitioning of the variability evidenced that microbial activity was influenced in a higher degree by the physical-chemical properties of soil than by study areas or periods. We identified similar fatty acid profiles in PETAR and PECJ and they were also similar to the ones found in a previous work in PECJ, what could indicate a specific EL-PLFA pattern in the Araucaria ecosystem. The fatty acids 10Me18:0 (actinobacteria), the saturated/unsaturated fatty acid ratio (sat/insat), the substrate utilization of -methyl-D-glucoside and 2-hydroxybenzoic acid were also related to PL (PETAR) and PF (PECJ), in both periods. The 18:19c fatty acid (fungi) and 16:17c (Gram-), the glucose-1-phosphate, -D-lactose and -hydroxybutyric acid were C-source for microbial communities of the impacted areas in both parks during the wet and dry periods. Therefore, these attributes are potential microbial indicators of soil quality in Araucaria forests, however, new evaluations are required to confirm these biomarkers and to monitor these areas.
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Quantifying stand structural complexity in woodland and dry Sclerophyll Forest, South-Eastern AustraliaMcElhinny, Chris, chris.mcelhinny@anu.edu.au January 2005 (has links)
In this thesis I present and test a methodology for developing a stand scale index of structural complexity. If properly designed such an index can act as a summary variable for a larger set of stand structural attributes, providing a means of ranking stands in terms of their structural complexity, and by association, their biodiversity and vegetation condition. This type of index can also facilitate the use of alternative policy instruments for biodiversity conservation, such as mitigation banking, auctions and offsets, that rely on a common currency the index value that can be compared or traded between sites. My intention was to establish a clear and documentable methodology for developing a stand scale index of structural complexity, and to test this methodology using data from real stands.¶
As a starting point, I reviewed the literature concerning forest and woodland structure and found there was no clear definition of stand structural complexity, or definitive suite of structural attributes for characterising it. To address this issue, I defined stand structural complexity as a combined measure of the number of different structural attributes present in a stand, and the relative abundance of each of these attributes. This was analogous to approaches that have quantified diversity in terms of the abundance and richness of elements. It was also concluded from the review, that stand structural complexity should be viewed as a relative, rather than absolute concept, because the potential levels of different structural attributes are bound within certain limits determined by the inherent characteristics of the site in question, and the biota of the particular community will have evolved to reflect this range of variation. This implied that vegetation communities with naturally simple structures should have the potential to achieve high scores on an index of structural complexity.¶
I proposed the following five-stage methodology for developing an index of stand structural complexity:
1. Establish a comprehensive suite of stand structural attributes as a starting point for developing the index, by reviewing studies in which there is an established relationship between elements of biodiversity and structural attributes.
2. Develop a measurement system for quantifying the different attributes included in the comprehensive suite.
3. Use this measurement system to collect data from a representative set of stands across the range of vegetation condition (highly modified to unmodified) and developmental stages (regrowth to oldgrowth) occurring in the vegetation communities in which the index is intended to operate.
4. Identify a core set of structural attributes from an analysis of these data.
5. Combine the core attributes in a simple additive index, in which attributes are scored relative to their observed levels in each vegetation community.¶
Stage one of this methodology was addressed by reviewing a representative sample of the literature concerning fauna habitat relationships in temperate Australian forests and woodlands. This review identified fifty-five studies in south-east and south-west Australia, in which the presence or abundance of different fauna were significantly (p<0.05) associated with vegetation structural attributes. The majority of these studies concerned bird, arboreal mammal, and ground mammal habitat requirements, with relatively fewer studies addressing the habitat requirements of reptiles, invertebrates, bats or amphibians. Thirty four key structural attributes were identified from these fifty-five studies, by grouping similar attributes, and then representing each group with a single generic attribute. This set, in combination with structural attributes identified in the earlier review, provided the basis for developing an operational set of stand level attributes for the collection of data from study sites.¶
To address stages two and three of the methodology, data were collected from one woodland community Yellow Box-Red Gum (E. melliodora-E. Blakelyi ) and two dry sclerophyll forest communities Broadleaved Peppermint-Brittle Gum (E. dives-E. mannifera ), Scribbly Gum-Red Stringybark (E. rossii E. macrorhyncha ) in a 15,000 km2 study area in the South eastern Highlands Bioregion of Australia. A representative set of 48 sites was established within this study area, by identifying 24 strata, on the basis of the three vegetation communities, two catchments, two levels of rainfall and two levels of condition, and then locating two sites (replicates) within each stratum. At each site, three plots were systematically established, to provide an unbiased estimate of stand level means for 75 different structural attributes.¶
I applied a three-stage analysis to identify a core set of attributes from these data. The first stage a preliminary analysis indicated that the 48 study sites represented a broad range of condition, and that the two dry sclerophyll communities could be treated as a single community, which was structurally distinct from the woodland community. In the second stage of the analysis, thirteen core attributes were dentified using the criteria that a core attribute should:¶
1. Be either, evenly or approximately normally distributed amongst study sites;
2. Distinguish between woodland and dry sclerophyll communities;
3. Function as a surrogate for other attributes;
4. Be efficient to measure in the field.
The core attributes were: Vegetation cover <0.5m Vegetation cover 0.5-6.0m; Perennial species richness; Lifeform richness; Stand basal area of live trees; Quadratic mean diameter of live stems; ln(number of regenerating stems per ha+1); ln(number of hollow bearing trees per ha+1);ln(number of dead trees per ha+1);sqrt(number of live stems per ha >40cm dbh); sqrt(total log length per ha); sqrt(total largelog length per ha); Litter dry weight per ha. This analysis also demonstrated that the thirteen core attributes could be modelled as continuous variables, and that these variables were indicative of the scale at which the different attributes operated.¶
In the third and final stage of the analysis, Principal Components Analysis was used to test for redundancy amongst the core attributes. Although this analysis highlighted six groupings, within which attributes were correlated to some degree, these relationships were not considered sufficiently robust to justify reducing the number of core attributes.¶
The thirteen core attributes were combined in a simple additive index, in which, each attribute accounted for 10 points in a total index value of 130. Attributes were rescaled as a score from 0-10, using equations that modelled attribute score as a function of the raw attribute data. This maintained a high correlation (r > 0.97, p< 0.0001) between attribute scores and the original attribute data. Sensitivity analysis indicated that the index was not sensitive to attribute weightings, and on this basis attributes carried equal weight. In this form my index was straightforward to apply, and approximately normally distributed amongst study sites.¶
I demonstrated the practical application of the index in a user-friendly spreadsheet, designed to allow landowners and managers to assess the condition of their vegetation, and to identify management options. This spreadsheet calculated an index score from field data, and then used this score to rank the site relative to a set of reference sites. This added a regional context to the operation of the index, and is a potentially useful tool for identifying sites of high conservation value, or for identifying sites where management actions have maintained vegetation quality. The spreadsheet also incorporated the option of calculating an index score using a subset of attributes, and provided a measure of the uncertainty associated with this score.¶
I compared the proposed index with five prominent indices used to quantify vegetation condition or habitat value in temperate Australian ecosystems. These were: Newsome and Catlings (1979) Habitat Complexity Score, Watson et al.s (2001) Habitat Complexity Score, the Site Condition Score component of the Habitat Hectares Index of Parkes et al. (2003), the Vegetation Condition Score component of the Biodiversity Benefits Index of Oliver and Parkes (2003), and the Vegetation Condition Score component of the BioMetric Assessment Tool of Gibbons et al. (2004). I found that my index differentiated between study sites better than each of these indices. However, resource and time constraints precluded the use of a new and independent data set for this testing, so that the superior performance of my index must be interpreted cautiously.¶
As a group, the five indices I tested contained attributes describing compositional diversity, coarse woody debris, regeneration, large trees and hollow trees these were attributes that I also identified as core ones. However, unlike these indices, I quantified weeds indirectly through their effect on indigenous plant diversity, I included the contribution of non-indigenous species to vegetation cover and did not apply a discount to this contribution, I limited the direct assessment of regeneration to long-lived overstorey species, I used stand basal area as a surrogate for canopy cover, I quantified litter in terms of biomass (dry weight) rather than cover, and I included the additional attributes of quadratic mean diameter and the number of dead trees.¶
I also concluded that Parkes et al. (2003), Oliver and Parkes (2003), and Gibbons et al. (2004), misapplied the concept of benchmarking, by characterising attributes in terms of a benchmark range or average level. This ignored processes that underpin variation at the stand level, such as the increased development of some attributes at particular successional stages, and the fact that attributes can respond differently to disturbance agents. It also produced indices that were not particularly sensitive to the differences in attribute levels occurring between stands. I suggested that a more appropriate application of benchmarking would be at the overarching level of stand structural complexity, using a metric such as the index developed in this thesis. These benchmarks could reflect observed levels of structural complexity in unmodified natural stands at different successional stages, or thresholds for structural complexity at which a wide range of biota are present, and would define useful goals for guiding on-ground management.
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Modulation des Processus Domino au départ des Accepteurs de Michael en série Chromone : Diversité par aza-Cyclisation, Arylation et Aryloxylation Métallocatalysées : Diversité par aza-Cyclisation, Arylation et Aryloxylation Métallocatalysées / Modulation of domino processes from the chromone based Michael acceptors platform : access to structural diversity through metal-catalyzed aza-cyclization, arylation and aryloxylationLepitre, Thomas 11 October 2017 (has links)
Le concept de la DOS (Diversity-Oriented Synthesis) est une nouvelle approche qui vise à générer des collections de petites molécules avec des hauts degrés de diversité et de complexité structurale. Diverses stratégies ont été mises en place pour y parvenir de manière la plus efficace possible à partir de simples substrats de départ.Dans ce contexte, ce travail de thèse a permis de montrer comment un processus domino avait tout le potentiel à être exploité en tant que formidable outil dans le cadre d’une approche DOS, générateur à la fois de complexité mais également de diversité structurale. Un précurseur connu et largement étudié pour son caractère exceptionnellement versatile a été valorisé dans ce contexte : la 3-formylchromone. Dans ce manuscrit, nous montrerons comment il est possible de moduler le cours d’un processus domino pour atteindre de hauts degrés de diversité structurale, à partir des chromones accepteurs de Michael-1,6 et d’amines primaires. Nous verrons en particulier comment le contrôle d'une ou de plusieurs étapes clefs des séquences réactionnelles impliquées peut être réalisé selon :(I) la modulation pertinente d’une ou plusieurs unité(s) de structure au sein des substrats de départ, (II) la modulation des paramètres réactionnels (solvants, température, additifs), et(III) l’induction d’un changement de réactivité au sein d’un intermédiaire réactionnel par addition d’un agent externe. / In the early 2000s a general consensus has emerged in which the molecular diversity within a given library of small molecules, rather than its size, has been recognized as a crucial requirement. Diversity-oriented synthesis (DOS) has emerged from this new paradigm. This novel approach aims to generate collections of small molecules with high degrees of structural diversity, in the most efficient way, starting from simple building-blocks. Since the generation of collections of structurally diverse small molecules in a DOS-driven approach constitutes a real challenge, diverse strategies have been set up for this purpose.In this line, this work has shed light on the great potential of a domino process as a valuable tool in a DOS-driven strategy, capable of generating both molecular diversity and architectural complexity. This study has been focused on the 3-formylchromone building block, a particular framework which has already proven being an exceptionally versatile precursor of molecular diversity. In this manuscript, we will highlight how it is possible to modulate the course of a domino process to achieve high degrees of molecular diversity, starting from the chromone based 1,6-Michael acceptors platform and primary amines as reaction partners. In particular we will show how it is feasible to control the course of particular steps involved in the domino process through: (I) the pertinent modulation of the Michael acceptors and the primary amines structures, (II) the modulation of the reaction parameters (solvent, temperature, additives), and (III) the tuning of the reactivity within a key reaction intermediate induced by the introduction of an external agent.
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Etude de cascades réactionnelles pallado-catalysées de fermeture d’allènamides et d’allylation directe de liaisons C-H et C-CO2H d’azoles, d’énamides et d’acides propioliques pour la diversité structurelle / Study of pallado-catalyzed cascades reactions for construction with allenamides and direct C-H allylation of C-H and C-CO2H bonds of azoles, enamides and propiolic acids for structural diversityHedouin, Jonathan 27 November 2017 (has links)
Le développement de plans synthétiques de molécules de complexité variable qui utilise des réactifs aisés d’accès et qui sont économes en atomes et en étapes est constamment au cœur des préoccupations du chimiste organicien pour accroître la diversité moléculaire de façon efficace et éco-responsable. La catalyse par les métaux de transition a permis de faire des progrès considérables dans la construction et la fonctionnalisation combinées d’hétérocycles d’intérêt à valeur ajoutée dans les sciences des produits naturels et les industries pharmaceutiques et phytosanitaires. Le principe synthétique consiste en l’enchaînement de processus standards élémentaires de transformations chimiques en un seul pot au sein de la sphère catalytique métallique. Un axe de progrès contemporain repose en particulier sur l’incorporation de processus de métallation catalytique de liaisons C-CO2H et C-H. Les travaux de thèse s’inscrivent dans ce jeune domaine de recherche initié au cours de la dernière décennie par plusieurs équipes de recherche dont celle de Jieping Zhu de l’école polytechnique fédérale de Lausanne compte parmi les pionnières et les plus actives. Ils ont visé notamment à implémenter consécutivement aux processus standards de carbopalladation intramoléculaire d’ortho-halogéno allénamides de Grigg de construction d’hétérocycles azotés très variés, d’une part des réactions d’allylation directe de la liaison C-H d’hétérocycles et d’énamides et d’autre part d’allylation décarboxylante d’acides propioliques. Après avoir évalué la réactivité des complexes pi-allypalladium conjugués à un atome d’azote dans la réaction, l’allylation directe de la laison C-H d’oxadiazoles et de 1,3-diazoles à fort caractère acide ainsi que des énamides, des séquences originales de construction et d’hétéroarylation combinées pallado-catalysées d’isoquinolinones et d’indoles ont été établies. Un protocole séquencé conduit en un seul pot et basé sur la génération in situ des allénamides, qui ne sont plus isolées, suivie de la réaction de construction et d’hétéroarylation combinées pallado-catalysée a ensuite été mis au point. Il a été exploité pour la préparation d’indoles, 1(2H)-isoquinoléïnones, isoquinoléïnes mais également des hétérocycles de taille supérieure, benzo-(2H)-azépine et benzo-(2H)-azocine intégrant des oxadiazoles et oxa(thia)zoles. Une première étude d’extension du concept synthétique a finalement été ciblée sur la construction et la propargylation combinée de la large gamme d’hétérocycles azotés obtenus précédemment en utilisant les acides propioliques comme partenaire de couplage. / The design of efficient and eco-friendly atom and step-economical synthetic plans of molecules using highly available starting materials is one of major objectives of organic chemist. Transition metal catalysis has allowed a bold step to build and functionalize consecutively, through a one-pot reaction, major nitrogen-containing heterocycles which are broadly present into numerous natural products, pharmaceutics and agrochemicals. The catalysis is based upon tandem inner-sphere elemental chemical transformations and one of major current challenge is to implement catalytic metallation of C-CO2H and C-H bonds. Involved in this young field of research initiated since the past decade from sevaral groups including pioneering and high active Jieping Zhu team of the Polytechnic School of Lausanne, the present study has been directed towards the design of innovative palladium-catalyzed domino Grigg nitrogen-containing heterocycles building through ortho-halogeno allenamides intramolecular carbopalladation process followed by direct C-H allylation of heterocycles and enamides or direct decarboxylative allylation of propiolic acids. After demonstrating the reactivity of nitrogen-conjugated pi-allypalladium complex in direct C-H allylation of acidic heterocycles, first palladium-catalyzed tandem build and heteroarylation of 1(2H)-isoquinoleinone and indole from ortho-halogeno allenamides was first envisaged. Efforts were next directed to the setting up of a one-pot protocol including in situ generation of allenamide followed by palladium-catalyzed domino building and functionalization of heterocycles. It was then hugely evaluated to the preparation of indole, 1(2H)-isoquinoleinones, isoquinolins as well as high-membred ring heterocycles such as benzo-(2H)-azepine and benzo-(2H)-azocine embedding with oxadiazoles and oxa(thia)zoles. An first extended synthetic concept towards the palladium-catalyzed tandem build and propargylation of nitrogen-containing heterocycles using sevral propiolic acids as coupling partners.
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Le Bilan écologique. Mesurer la perturbation anthropogénique de l’Ecosphère et de la Biosphère (un bilan de l'Anthropocène). Caractériser les voies du Développement écologique des territoires. / The ecological Balance sheet. Measuring the anthropogenic disturbance of the Ecosphere and the Biosphere (an Anthropocene assessment). Characterizing the ways of the territories ecological development.Loiret, Richard 27 January 2016 (has links)
(Résumé de la thèse) Ayant constaté l’échec de ses Objectifs 2010 pour la biodiversité, dont, entre autres, l’incapacité de l’Empreinte écologique à rendre compte de la biodiversité, la Convention sur la Diversité Biologique a adopté en 2011 "Les objectifs d’Aichi (2011-2020) pour la biodiversité". Parmi ceux-ci les objectifs 1 et 2 concernent la prise de conscience des valeurs de la biodiversité, leur intégration dans les processus de planification nationaux et locaux de développement, et leur incorporation dans les comptabilités nationales. Ce en quoi ces objectifs de la CDB convergent désormais avec ceux des Nations Unies concernant le Système de Comptabilité Economique et Environnementale (SCEE). La présente thèse s’inscrit dans ce cadre de questionnement unifié. Elle a le double objectif : (a) de rechercher, fonder et mettre au point une unité de mesure biophysique de la diversité biologique caractérisant tout aussi bien l’ordre naturel que le désordre anthropogénique, et (b) d’incorporer celle-ci dans un nouveau système de comptabilité physique, le Bilan écologique. Celui-ci est susceptible de comparer, à toutes échelles territoriales, le Passif écologique des collectivités urbaines, vu comme le reflet biophysique de leur comptabilité monétaire, à l’Actif écologique de leurs espaces naturels, afin de révéler les relations de cause à effet, et de signifier les impacts cumulés de la perturbation anthropogénique sur l’Ecosphère et la Biosphère. Il aurait ainsi vocation, à terme, à nous permettre de caractériser les voies d’un développement véritablement écologique des territoires. / (Abstract of the thesis) Having noted the failure of its 2010 targets for biodiversity, including, among others, the inability of the Ecological Footprint to account for biodiversity, the Convention on Biological Diversity adopted in 2011 "The 2011-2020 Aichi Targets for biodiversity". Among these, objectives 1 and 2 concern awareness of the values of biodiversity, their integration into national and local development planning process, and their incorporation into national accounts. This how these objectives of the CBD converge now with those of the United Nations for the System of Environmental-Economic Accounting (SEEA). This thesis lie within this unified questioning framework. It has the double purpose : (a) of searching for, founding and developing a biophysical measurement unit of biodiversity, characterizing just as well the natural order as the anthropogenic disorder, and (b) to incorporate it into a new physical accounting system, the Ecological balance sheet. The latter is likely to compare, for all territorial scales, the Ecological liability of urban communities, seen as the biophysical reflection of their monetary accounting, to the Ecological asset of their natural spaces, in order to reveal the relationships of cause and effect, and to signify the cumulative impacts of anthropogenic disturbance on the Ecosphere and the Biosphere. In the end, it would have so vocation to enable us to characterize the ways of a truly ecological development of the territories.
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