Studio delle comunicazioni intraspecifiche in Anarsia lineatella Zeller

Sebbene Anarsia lineatella sia un fitofago ormai da anni introdotto e diffuso in Italia, ancora poco si conosce circa le sue abitudini riproduttive. In considerazione della elevata dannosità di A. lineatella nei pescheti del nord Italia e delle scarse conoscenze sulla sua biologia, si è evidenziata la necessità di approfondire la conoscenza di questo fitofago. Pertanto gli scopi di questa ricerca hanno riguardato l’approfondimento delle conoscenze sui sistemi di comunicazione intraspecifici utilizzati da A. lineatella; la valutazione dell’efficacia di diverse miscele di feromone sintetico, in laboratorio utilizzando anche densità diverse di popolazioni di anarsia e in campo utilizzando gabbie di accoppiamento appositamente costruite, posizionate in frutteti a conduzione biologica nel nord Italia e messe a confronto con gabbie che utilizzavano come fonte attrattiva femmine vergini di tre giorni di età. Sono state condotte prove sul comportamento di maschi di A. lineatella di differenti età in risposta al feromone emesso da femmine vergini di tre giorni di età e al feromone emesso da erogatori di materiale plastico contenenti differenti miscele di feromone sintetico. Sono stati condotti studi per verificare l’influenza del contenuto di alcol ((E)5-10:OH) nella miscela feromonica sulla capacità di inibizione degli accoppiamenti, sottoponendo gli insetti a differenti concentrazioni di feromone in modo da verificare eventuali differenze di attività delle diverse miscele, differenze che emergerebbero con evidenza maggiore alle minori concentrazioni. Alcune prove sono state effettuate anche con differenti densità di popolazione, poiché una maggiore densità di popolazione determina una maggiore probabilità di accoppiamento, evidenziando più chiaramente i limiti di efficacia della miscela utilizzata. Inoltre sono state effettuate prove di campo per confrontare due modelli di erogatore per la confusione sessuale di anarsia contenenti miscele con differenti percentuali di alcol Inoltre, poiché nei pescheti la presenza di A. lineatella è pressoché sempre associata a quella di Cydia molesta e l’applicazione del metodo della confusione deve spesso essere applicato per controllare entrambi gli insetti, può risultare vantaggioso disporre di un unico erogatore contenente entrambi i feromoni; è stato quindi valutato un erogatore contenente una miscela dei due feromoni per verificare eventuali interazioni che possano ridurre l’efficacia.

The influence of individual and colony level variation in behavior on colony performance in ants

In my dissertation I investigated the influence of behavioral variation between and within ant colonies on group performance. In particular, I analyzed how evolution shapes behavior in response to ecological conditions, and whether within-group diversity improves productivity as suggested by theory. Our field and laboratory experiments showed that behavioral diverse groups are more productive. Different aggression levels within colonies were beneficial under competitive field situations, whereas diversity in brood care and exploratory behavior were favored in non-competitive laboratory situations. We then examined whether population density and social parasite presence shape aggression through phenotypic plasticity and/or natural selection. The importance of selection was indicated by the absence of density or parasite effects on aggression in a field manipulation. Indeed, more aggressive colonies fared better under high density and during parasite attack. When analyzing the proximate causes of individual behavioral variation, ovarian development was shown to be linked to division of labor and aggressiveness. Finally, our studies show that differences in the collective behavior can be linked to immune defense and productivity. My dissertation demonstrates that behavioral variation should be studied on multiple scales and when possible combined with physiological analyses to better understand the evolution of animal personalities in social groups.rn

Global modeling of pollutant transport and deposition from anthropogenic emission hot spots on global scale

Urban centers significantly contribute to anthropogenic air pollution, although they cover only a minor fraction of the Earth's land surface. Since the worldwide degree of urbanization is steadily increasing, the anthropogenic contribution to air pollution from urban centers is expected to become more substantial in future air quality assessments. The main objective of this thesis was to obtain a more profound insight in the dispersion and the deposition of aerosol particles from 46 individual major population centers (MPCs) as well as the regional and global influence on the atmospheric distribution of several aerosol types. For the first time, this was assessed in one model framework, for which the global model EMAC was applied with different representations of aerosol particles. First, in an approach with passive tracers and a setup in which the results depend only on the source location and the size and the solubility of the tracers, several metrics and a regional climate classification were used to quantify the major outflow pathways, both vertically and horizontally, and to compare the balance between pollution export away from and pollution build-up around the source points. Then in a more comprehensive approach, the anthropogenic emissions of key trace species were changed at the MPC locations to determine the cumulative impact of the MPC emissions on the atmospheric aerosol burdens of black carbon, particulate organic matter, sulfate, and nitrate. Ten different mono-modal passive aerosol tracers were continuously released at the same constant rate at each emission point. The results clearly showed that on average about five times more mass is advected quasi-horizontally at low levels than exported into the upper troposphere. The strength of the low-level export is mainly determined by the location of the source, while the vertical transport is mainly governed by the lifting potential and the solubility of the tracers. Similar to insoluble gas phase tracers, the low-level export of aerosol tracers is strongest at middle and high latitudes, while the regions of strongest vertical export differ between aerosol (temperate winter dry) and gas phase (tropics) tracers. The emitted mass fraction that is kept around MPCs is largest in regions where aerosol tracers have short lifetimes; this mass is also critical for assessing the impact on humans. However, the number of people who live in a strongly polluted region around urban centers depends more on the population density than on the size of the area which is affected by strong air pollution. Another major result was that fine aerosol particles (diameters smaller than 2.5 micrometer) from MPCs undergo substantial long-range transport, with about half of the emitted mass being deposited beyond 1000 km away from the source. In contrast to this diluted remote deposition, there are areas around the MPCs which experience high deposition rates, especially in regions which are frequently affected by heavy precipitation or are situated in poorly ventilated locations. Moreover, most MPC aerosol emissions are removed over land surfaces. In particular, forests experience more deposition from MPC pollutants than other land ecosystems. In addition, it was found that the generic treatment of aerosols has no substantial influence on the major conclusions drawn in this thesis. Moreover, in the more comprehensive approach, it was found that emissions of black carbon, particulate organic matter, sulfur dioxide, and nitrogen oxides from MPCs influence the atmospheric burden of various aerosol types very differently, with impacts generally being larger for secondary species, sulfate and nitrate, than for primary species, black carbon and particulate organic matter. While the changes in the burdens of sulfate, black carbon, and particulate organic matter show an almost linear response for changes in the emission strength, the formation of nitrate was found to be contingent upon many more factors, e.g., the abundance of sulfuric acid, than only upon the strength of the nitrogen oxide emissions. The generic tracer experiments were further extended to conduct the first risk assessment to obtain the cumulative risk of contamination from multiple nuclear reactor accidents on the global scale. For this, many factors had to be taken into account: the probability of major accidents, the cumulative deposition field of the radionuclide cesium-137, and a threshold value that defines contamination. By collecting the necessary data and after accounting for uncertainties, it was found that the risk is highest in western Europe, the eastern US, and in Japan, where on average contamination by major accidents is expected about every 50 years.

Applications of GIS and remote sensing techniques for studying the housing patterns in Cairo Governorate

The main objective of this study is to reveal the housing patterns in Cairo as one of the most rapidly urbanizing city in the developing world. The study outlines the evolution of the housing problem and its influencing factors in Egypt generally and in Cairo specifically. The study takes into account the political transition from the national state economy to the open door policy, the neo-liberal period and finally to the housing situation after the January 2011 Revolution. The resulting housing patterns in Cairo Governorate were identified as (1) squatter settlements, (2) semi-informal settlements, (3) deteriorated inner pockets, and (4) formal settlements. rnThe study concluded that the housing patterns in Cairo are reflecting a multifaceted problem resulting in: (1) the imbalance between the high demand for affordable housing units for low-income families and the oversupply of upper-income housing, (2) the vast expansion of informal areas both on agricultural and desert lands, (3) the deterioration of the old parts of Cairo without upgrading or appropriate replacement of the housing structure, and (4) the high vacancy rate of newly constructed apartmentsrnThe evolution and development of the current housing problem were attributed to a number of factors. These factors are demographic factors represented in the rapid growth of the population associated with urbanization under the dictates of poverty, and the progressive increase of the prices of both buildable land and building materials. The study underlined that the current pattern of population density in Cairo Governorate is a direct result of the current housing problems. Around the depopulation core of the city, a ring of relatively stable areas in terms of population density has developed. Population densification, at the expense of the depopulation core, is characterizing the peripheries of the city. The population density in relation to the built-up area was examined using Landsat-7 ETM+ image (176/039). The image was acquired on 24 August 2006 and considered as an ideal source for land cover classification in Cairo since it is compatible with the population census 2006.rnConsidering that the socio-economic setting is a driving force of change of housing demand and that it is an outcome of the accumulated housing problems, the socio-economic deprivations of the inhabitants of Cairo Governorate are analyzed. Small administrative units in Cairo are categorized into four classes based on the Socio-Economic Opportunity Index (SEOI). This index is developed by using multiple domains focusing on the economic, educational and health situation of the residential population. The results show four levels of deprivation which are consistent with the existing housing patterns. Informal areas on state owned land are included in the first category, namely, the “severely deprived” level. Ex-formal areas or deteriorated inner pockets are characterized as “deprived” urban quarters. Semi-informal areas on agricultural land concentrate in the third category of “medium deprived” settlements. Formal or planned areas are included mostly in the fourth category of the “less deprived” parts of Cairo Governorate. rnFor a better understanding of the differences and similarities among the various housing patterns, four areas based on the smallest administrative units of shiakhat were selected for a detailed study. These areas are: (1) El-Ma’desa is representing a severely deprived squatter settlement, (2) Ain el-Sira is an example for an ex-formal deprived area, (3) El-Marg el-Qibliya was selected as a typical semi-informal and medium deprived settlement, and (4) El-Nozha is representing a formal and less deprived area.rnThe analysis at shiakhat level reveals how the socio-economic characteristics and the unregulated urban growth are greatly reflected in the morphological characteristics of the housing patterns in terms of street network and types of residential buildings as well as types of housing tenure. It is also reflected in the functional characteristics in terms of land use mix and its degree of compatibility. It is concluded that the provision and accessibility to public services represents a performance measure of the dysfunctional structure dominating squatter and semi-informal settlements on one hand and ample public services and accessibility in formal areas on the other hand.rn

Mortality from road traffic accidents in Switzerland: longitudinal and spatial analyses

Road traffic accidents (RTA) are an important cause of premature death. We examined socio-demographic and geographical determinants of RTA mortality in Switzerland by linking 2000 census data to RTA mortality records 2000-2005 (ICD-10 codes V00-V99). Data from 5.5 million residents aged 18-94 years, 1744 study areas, and 1620 RTA deaths were analyzed, including 978 deaths (60.4%) in motor vehicle occupants, 254 (15.7%) in motorcyclists, 107 (6.6%) in cyclists, and 259 (16.0%) in pedestrians. Weibull survival models and Bayesian methods were used to calculate hazard ratios (HR), and standardized mortality ratios (SMR) across study areas. Adjusted HR comparing women with men ranged from 0.04 (95% CI 0.02-0.07) in motorcyclists to 0.43 (95% CI 0.32-0.56) in pedestrians. There was a u-shaped relationship with age in motor vehicle occupants and motorcyclists. In cyclists and pedestrians, mortality increased after age 55 years. Mortality was higher in individuals with primary education (HR 1.53; 95% CI 1.29-1.81), and higher in single (HR 1.24; 95% CI 1.05-1.46), widowed (HR 1.31; 95% CI 1.05-1.65) and divorced individuals (HR 1.62; 95% CI 1.33-1.97), compared to persons with tertiary education or married persons. The association with education was particularly strong for pedestrians (HR 1.87; 95% CI 1.20-2.91). RTA mortality increased with decreasing population density of study areas for motor vehicle occupants (test for trend p<0.0001) and motorcyclists (p=0.0021) but not for cyclists (p=0.39) or pedestrians (p=0.29). SMR standardized for socio-demographic and geographical variables ranged from 82 to 190. Prevention efforts should aim to reduce inequities across socio-demographic and educational groups, and across geographical areas, with interventions targeted at high-risk groups and areas, and different traffic users, including pedestrians.

The Modern Urban Cartography of Present-day Bratislava.

Following an extensive survey of sources on urban development and comparative analyses of Bratislava and other major Central European cities and Slovak regional centres, Divinsky completed a detailed study of Bratislava's spatial structure using the most recent approaches of the so-called Belgian school. He also produced an intraurban regionalisation of Bratislava as a multi-structural interactive model, mapped and characterised by the cardinal parameters, processes, trends and inequalities of population and housing in each spatial element of the model. The field survey entailed a seven-month physical investigation of the territory using a "street by street, block by block, house by house and locality by locality" system to ensure that no areas were missed. A second field survey was carried out two years later to check on transformations. An important feature of the research was the concept of the morphological city, which was defined as "a continuously built-up area of all urban functions (i.e. excluding agricultural lands and forests lying outside the city which serve for half-day recreation) made up of spatial-structural units fulfilling certain criteria". The most important criteria was a minimum population density per unit of no less than 650 persons per square kilometre, except in the case of units totally surrounded by units of higher densities, where it could be lower. The morphological city as defined here includes only 36% of the territory of the administrative city, but 95% of the popula tion, giving a much higher population density which better reflects the urban reality of Bratislava.

Carbon pools and poverty peaks in Lao PDR

Reducing Emissions from Deforestation and forest Degradation and enhancing forest carbon stocks in developing countries (REDD+) is heavily promoted in Laos. REDD+ is often perceived as an opportunity to jointly address climate change and poverty and, therefore, could come timely for Laos to combine its prominent national target of poverty eradication with global climate mitigation efforts. Countrywide planning of the right approaches to REDD+ combined with poverty alleviation requires knowledge of the spatial combination of poverty and carbon stocks at the national level. This study combined spatial information on carbon stored in vegetation and on poverty and created carbon-poverty typologies for the whole country at the village level. We found that 11% of the villages of Laos have high to very high average village-level carbon stock densities and a predominantly poor population. These villages cover 20% of the territory and are characterized by low population density. Shifting cultivation areas in the northwestern parts of the country have a higher carbon mitigation potential than areas in the central and eastern highlands due to a more favorable climate. Finally, we found that in Laos the majority (58%) of poor people live in areas with low carbon stock densities without major potential to store carbon. Accordingly, REDD+ cannot be considered a core instrument for poverty alleviation. The carbon-poverty typologies presented here provide answers to basic questions related to planning and managing of REDD+. They could serve as a starting point for the design of systems to monitor both socioeconomic and environmental development at the national level.

An analysis of the spatial and temporal patterns of highly pathogenic avian influenza occurrence in Vietnam using national surveillance data

The objectives of this study were to describe the spatio-temporal pattern of an epidemic of highly pathogenic avian influenza (HPAI) in Vietnam and to identify potential risk factors for the introduction and maintenance of infection within the poultry population. The results indicate that during the time period 2004–early 2006 a sequence of three epidemic waves occurred in Vietnam as distinct spatial and temporal clusters. The risk of outbreak occurrence increased with a greater percentage of rice paddy fields, increasing domestic water bird and chicken density. It increased with reducing distance to higher population density aggregations, and in the third epidemic wave with increasing percentage of aquaculture. The findings indicate that agri-livestock farming systems involving domestic water birds and rice production in river delta areas are important for the maintenance and spread of infection. While the government’s control measures appear to have been effective in the South and Central parts of Vietnam, it is likely that in the North of Vietnam the vaccination campaign led to transmission of infection which was subsequently brought under control.

Assessing the effectiveness of a long-standing rocky intertidal protected area and its contribution to the regional conservation of species, habitats and assemblages

1. The acceptance of reserves as a useful management strategy relies on evidence of their effectiveness in preserving stocks of harvested species and conserving biodiversity. A history of ad hoc decisions in terrestrial and marine protected area planning has meant that many of these areas are contributing inefficiently to conservation goals. The conservation value of existing protected areas should be assessed when planning the placement of additional areas in a reserve network. 2. This study tested (1) the effectiveness of protection for intertidal molluscs of a marine reserve (Bouddi Marine Extension, NSW, Australia) established in 1971, and (2) the contribution of the protected area to the conservation of regional species, assemblages, and habitats. 3. The shell length and population density of one harvested (Cellana tramoserica), and three non-harvested species (Bembicium nanum, Morula marginalba, Nerita atramentosa) of intertidal molluscs were examined in the protected area and two reference locations over two seasons. 4. The heavily collected limpet C. tramoserica was significantly larger in the protected area and was the only species to exhibit a significant difference. No species significantly differed in population density between the protected area and reference locations. 5. Temporally replicated surveys of macro-molluscs at 21 locations over 75km of coastline identified that the existing protected area included 50% of species, two of five assemblage types and 19 of 20 intertidal rocky shore habitats surveyed in the study region. Reservation of a further three rocky reefs would protect a large proportion of species (71%), a representative of each assemblage and all habitat types. 6. Despite originally being selected in the absence of information on regional biodiversity, the protected area is today an effective starting point for expansion to a regional network of intertidal protected areas.

Lake sediments as archives of recurrence rates and intensities of past flood events

Palaeoflood hydrology is an expanding field as the damage potential of flood and flood-related processes are increasing with the population density and the value of the infrastructure. Assessing the risk of these hazards in mountainous terrain requires knowledge about the frequency and severness of such events in the past. A wide range of methods is employed using diverse biologic, geomorphic or geologic evidences to track past flood events. Impact of floods are studied and dated on alluvial fans and cones using for example the growth disturbance of trees (Stoffel and Bollschweiler 2008; Schneuwly-Bollschweiler and Stoffel 2012: this volume) or stratigraphic layers deposited by debris flows, allowing to reconstruct past flood frequencies (Bardou et~al. 2003). Further downstream, the classical approach of palaeoflood hydrology (Kochel and Baker 1982) utilizes geomorphic indicators such as overbank sediments, silt lines and erosion features of floods along a river (e.g. Benito and Thorndycraft 2005). Fine-grained sediment settles out of the river suspension in eddies or backwater areas, where the flow velocity of the river is reduced. Records of these deposits at different elevations across a river’s profile can be used to assess the discharge of the past floods. This approach of palaeoflood hydrology studies was successfully applied in several river catchments (e.g. Ely et al. 1993; Macklin and Lewin 2003; O’Connor et al. 1994; Sheffer et al. 2003; Thorndycraft et al. 2005; Thorndycraft and Benito 2006). All these different reconstruction methods have their own advantages and disadvantages, but often these studies have a limited time coverage and the records are potentially incomplete due to lateral limits of depositional areas and due to the erosional power of fluvial processes that remove previously deposited flood witnesses. Here, we present a method that follows the sediment particle transported by a flood event to its final sink: the lacustrine basin.

Ecosystem service trade-offs and stakeholder claims - a meso-scale study from a Madagascar biodiversity hotspot

The north-eastern escarpment of Madagascar has been labelled a global biodiversity hotspot due to its extremely high rates of endemic species which are heavily threatened by accelerated deforestation rates and landscape change. The traditional practice of shifting cultivation or "tavy" used by the majority of land users in this area to produce subsistence rice is commonly blamed for these threats. A wide range of stakeholders ranging from conservation to development agencies, and from the private to the public sector has therefore been involved in trying to find solutions to protect the remaining forest fragments and to increase agricultural production. Consequently, provisioning, regulating and socio-cultural services of this forest-mosaic landscape are fundamentally altered leading to trade-offs between them and consequently new winners and losers amongst the stakeholders at different scales. However, despite a growing amount of evidence from case studies analysing local changes, the regional dynamics of the landscape and their contribution to such trade-offs remain poorely understood. This study therefore aims at using generalised landscape units as a base for the assessment of multi-level stakeholder claims on ecosystem services to inform negotiation, planning and decision making at a meso-scale. The presented study applies a mixed-method approach combining remote sensing, GIS and socio-economic methods to reveal current landscape dynamics, their change over time and the corresponding ecosystem service trade-offs induced by diverse stakeholder claims on the regional level. In a first step a new regional land cover classification for three points in time (1995, 2005 and 2011) was conducted including agricultural classes characteristic for shifting cultivation systems. Secondly, a novel GIS approach, termed “landscape mosaics approach” originally developed to assess dynamics of shifting cultivation landscapes in Laos was applied. Through this approach generalised landscape mosaics were generated allowing for a better understanding of changes in land use intensities instead of land cover. As a next step we will try to use these landscape units as proxies to map provisioning and regulating ecosystem services throughout the region. Through the overlay with other regional background data such as accessibility and population density and information from a region-wide stakeholder analysis, multiscale trade-offs between different services will be highlighted. The trade-offs observed on the regional scale will then be validated through a socio-economic ground-truthing within selected sites at the local scale. We propose that such meso-scale knowledge is required by all stakeholders involved in decision making towards sustainable development of north-eastern Madagascar.

Suppression of T lymphocyte activation in simulated microgravity

Immune dysfunction is encountered during spaceflight. Various aspects of spaceflight, including microgravity, cosmic radiation, and both physiological and psychological stress, may perturb immune function. We sought to understand the impact of microgravity alone on the cellular mechanisms critical to immunity. Clinostatic RWV bioreactors that simulate aspects of microgravity were used to analyze the response of human PBMC to polyclonal and oligoclonal activation. PHA responsiveness in the RWV bioreactor was almost completely diminished. IL-2 and IFN-$\gamma$ secretion was reduced whereas IL-1$\beta$ and IL-6 secretion was increased, suggesting that monocytes may not be as adversely affected by simulated microgravity as T cells. Activation marker expression (CD25, CD69, CD71) was significantly reduced in RWV cultures. Furthermore, addition of exogenous IL-2 to these cultures did not restore proliferation. Antigen specific T cell activation, including the mixed-lymphocyte reaction, tetanus toxoid responsiveness, and Borrelia activation of a specific T cell line, was also suppressed in the RWV bioreactor.^ The role of altered culture conditions in the suppression of T cell activation were considered. Potential reduced cell-cell and cell-substratum interactions in the RWV bioreactor may play a role in the loss of PHA responsiveness. However, PHA activation in Teflon culture bags that limit cell-substratum interactions was not affected. Furthermore, increasing cell-population density, and therefore cell-cell interactions, in the RWV cultures did not help restore PHA activation. However, placing PBMC within small collagen beads did partially restore PHA responsiveness. Finally, activation of purified T cells with crosslinked CD2/CD28 or CD3/CD28 antibody pairs, which does not require costimulation through cell-cell contact, was completely suppressed in the RWV bioreactor suggesting a defect internal to the T cell.^ Activation of both PBMC and purified T cells with PMA and ionomycin was unaffected by RWV culture, indicating that signaling mechanisms downstream of PKC activation and calcium flux are not sensitive to simulated microgravity. Furthermore, sub-mitogenic doses of PMA alone but not ionomycin alone restored PHA responsiveness of PBMC in RWV culture. Thus, our data indicate that during polyclonal activation in simulated microgravity, there is a specific dysfunction within the T cell involving the signaling pathways upstream of PKC activation. ^

Seasonal controls on grassland microbial biogeography: Are they governed by plants, abiotic properties or both?

Temporal dynamics create unique and often ephemeral conditions that can influence soil microbial biogeography at different spatial scales. This study investigated the relation between decimeter to meter spatial variability of soil microbial community structure, plant diversity, and soil properties at six dates from April through November. We also explored the robustness of these interactions over time. An historically unfertilized, unplowed grassland in southwest Germany was selected to characterize how seasonal variability in the composition of plant communities and substrate quality changed the biogeography of soil microorganisms at the plot scale (10 m x 10 m). Microbial community spatial structure was positively correlated with the local environment, i.e. physical and chemical soil properties, in spring and autumn, while the density and diversity of plants had an additional effect in the summer period. Spatial relationships among plant and microbial communities were detected only in the early summer and autumn periods when aboveground biomass increase was most rapid and its influence on soil microbial communities was greatest due to increased demand by plants for nutrients. Individual properties exhibited varying degrees of spatial structure over the season. Differential responses of Gram positive and Gram negative bacterial communities to seasonal shifts in soil nutrients were detected. We concluded that spatial distribution patterns of soil microorganisms change over a season and that chemical soil properties are more important controlling factors than plant density and diversity. Finer spatial resolution, such as the mm to cm scale, as well as taxonomic resolution of microbial groups, could help determine the importance of plant species density, composition, and growth stage in shaping microbial community composition and spatial patterns. (C) 2014 The Authors. Published by Elsevier Ltd. All rights reserved.

Indigenous land reconfiguration and fragmented institutions: a historical political ecology of Tsimane’ lands (Bolivian Amazon)

Lands inhabited by indigenous peoples often have low population density but abundant natural resources. For those reasons, many actors have historically attempted to occupy those lands or use the resources in them. Increasing pressures over lands occupied by indigenous peoples have resulted in the awakening of indigenous peoples over their rights to land and resources generating many debates over indigenous peoples' rights to land and self-governance. In this article, we provide a historical and geographical overview of territorial and governance issues among the Tsimane', an indigenous group native to the Bolivian Amazon. We examine how the Bolivian state economic policies implemented during the 20th century affected the Tsimane' ancestral lands, and how – over the late-20th century – the Bolivian state accommodated Tsimane' claims to lands in between multiple interests. We show how national policies led to the reconfiguration of Tsimane' territoriality and to a fragmented institutional representation. Current indigenous territories and indigenous political representation are an expression of conflictive policies that have involved multiple actors and their specific interests on indigenous lands and its resources.

Possible Demographic Consequences of Intraspecific Shelter Competition Among American Lobsters

Pioneering work by J. Stan Cobb described how habitat architecture and body size scaling affect shelter-related behavior of American lobsters. Subsequent research suggested that shelter availability and competition could set local carrying capacity and demographics for this species. To determine how shelter spacing affects population density, the intensity of intraspecific competition and the distribution of body size for this species, I deployed sets of 10 identically sized artificial shelters spaced at distances of 2.5, 0.5, 1.0, 1.5 and 2.0 meters on otherwise featureless substrate at 10 m depth in mid-coast Maine, U.S.A. Five sets had two parallel strings of five opposing shelters and an additional linear string set 2 to apart without opposing shelters was the most widely separated treatment. Shelters spaced I m apart and closer had higher lobster population densities, more intraspecific competition and higher proportions of empty shelters. Surprisingly, lobsters there were also significantly smaller, declining from 62.7 mm to 50.9 on the carapace (CL) for 2 to linear to 0.25 m spaced shelters, respectively. Nearly all 932 lobsters measured in this study were juvenile (< 90 mm CL) and preharvestable (< 83 mm CL) sized, so mate selection and fishing effects were unlikely. At the scale of the experiment, larger lobsters leave or avoid areas of high lobster population density and intense competition for areas of low population density and relaxed competition (called "demographic diffusion"). Scuba surveys in coastal zones found lobster population densities scale with shelter densities and were highest in boulder habitat where, like the experiment, more than half the shelters were vacant. Fisheries independent scuba and trawl surveys in Maine's shallow coastal zone repeatedly recorded declines of preharvestable, lobsters larger than 60 turn CL in size and increases of those sizes offshore and in deep water. It is possible that this demographic diffusion is driven by behaviors associated with intraspecific shelter competition.