Microscale models and urban heat island studies: a systematic review.

Urban climate analysis usually uses data from weather stations, traverse, or satellite images. However, this methodology also has its limitations, since the series of data for climate monitoring can be scarce. Another option that has been earning attention in recent years is numeric models, which perform simulations in urban climate. Obtaining climate data is extremely important for climatology, as well as for related areas, such as urban planning, which uses this data to know how to best order the territory according to climate conditions and their projections. Our study aimed to carry out a literature review regarding urban heat island analysis methodologies, with emphasis on the use of models. We evaluated over 200 scientific documents and we used 68 in the results of this work, reporting different types of models. The results indicated that most of the works on urban climate use a more traditional methodological approach, with fieldwork, whereas studies with models have been carried out in a specific way, especially in cities in the northern hemisphere. Among the articles evaluated, the majority were published in Elsevier publisher journals, which have a more interdisciplinary approach. The most studied models were ENVI-met, SOLWEIG, PALM-4U, RayMan, and TEB. In this way, this work pointed out, unlike other works of review in urban climate methodologies, the difficulty in obtaining field data, emphasizing their importance, with regard to studies of urban heat islands and urban planning. We also conclude that the progress and development of the state of the art in numerical models are conditioned to scientific investment in the area.

Preferred temperature in the warmth of cities: Body size, sex and development stage matter more than urban climate in a ground-dwelling spider.

Most ectotherms rely on behavioural thermoregulation to maintain body temperatures close to their physiological optimum. Hence, ectotherms can drastically limit their exposure to thermal extremes by selecting a narrower range of temperatures, which includes their preferred temperature (Tpref). Despite evidence that behavioural thermoregulation can be adjusted by phenotypic plasticity or constrained by natural selection, intraspecific Tpref variations across environmental gradients remain overlooked as compared to other thermal traits like thermal tolerance. Here, we analyzed Tpref variation of spider populations found along a gradient of urban heat island (UHI) which displays large thermal variations over small distances. We measured two components of the thermal preference, namely the mean Tpref and the Tpref range (i.e., standard deviation) in 557 field-collected individuals of a common ground-dwelling spider (Pardosa saltans, Lycosidae) using a laboratory thermal gradient. We determined if Tpref values differed among ten populations from contrasting thermal zones. We showed that endogenous factors such as body size or sex primarily determine both mean Tpref and Tpref range. The Tpref range was also linked to the UHI intensity to a lesser extent, yet only in juveniles. The absence of relationship between Tpref metrics and UHI in adult spiders suggests a Bogert effect according to which the ability of individuals to detect and exploit optimal microclimates weakens the selection pressure of temperatures (here driven by UHI) on their thermal physiology. Alternatively, this lack of relationship could also indicate that temperature patterns occurring at the scale of the spiders' micro-habitat differ from measured ones. This study shows the importance of considering both inter-individual and inter-population variations of the Tpref range when conducting Tpref experiments, and supports Tpref range as being a relevant measure to inform on the strength of behavioural thermoregulation in a given population.

Low levels of shade and climate change adaptation of Arabica coffee in southeastern Brazil.

Coffee is one of the most consumed beverages in the world, and its international market has been growing for many years. Unfortunately, the Brazilian coffee production is threatened by high temperatures projected by climate change models. We evaluated three schemes of low levels of shade, which avoid the loss of production, as a strategy to adapt coffee to possible climate change. Additionally, as field measurements are expensive and often difficult to implement, we used numerical simulation to complement the evaluation. The microclimate simulator software Envi-met is a computer program often used to simulate urban environments, and we tested it on agriculture design. We verified that the shaded schemes assessed in the field decreased the air temperature in 0.6 °C in the studied period and reduced other possible climate stressors such as wind speed, radiation and raised air humidity in the dry period. Envi-met described the studied meteorological variable cycle very well, showing that combining numerical modelling and field research may be an important tool for planning the adaptation of the coffee sector to possible climate change, allowing growers choose a proper technique for their regions and environmental conditions. Finally, we highlighted the importance of planning the shade scheme on coffee areas in an interdisciplinary approach, including local climate evaluation to achieve a balance between temperature attenuation and production.

The DURAMAZ indicator system: a cross-disciplinary comparative tool for assessing ecological and social changes in the Amazon.

During the last 20 years, the Amazon region has been at the same time a place of massive ecological and social change and a laboratory of experiments aimed at promoting sustainable development. Policies and project initiatives involving diverse social groups and environmental contexts have been implemented across the region. They have resulted in mixed outcomes and trade-offs between social and environmental dimensions, making their impact at the local level difficult to assess and their successes difficult to generalize. The objective of the DURAMAZ research project was to provide a better understanding of these impacts. It produced a multi-dimensional indicator system designed to allow a holistic view of sustainable development at local and subregional levels and a comparative perspective across 12 research sites, from an isolated indigenous village to smallholders and agribusiness areas in Mato Grosso. The results of the first observation campaign (2007-2009) show that despite the claim of promoting sustainable development, no project was able to untie the 'Gordian knot' of development in the Amazon. Communities continue to face the old dilemma of either enjoying a preserved ecosystem but enduring adverse life conditions, or enjoying better living at the expense of forest cover. Another finding is that the subregional context is very important in shaping the impacts of regional policies. Thus, the same policy will not always have the same effect, depending on in which context it is applied. Finally, we found that cultural factors and a sense of place play a more important role than economic factors when it comes to the way people evaluate their own situation. This research provides the basis for a second phase of the project (2012-2016) in which we will continue to expand our sample and to refine our methodologies with the goal of transforming the initiative into a network of observatories of sustainable development in the Amazon.

Impact of land-cover change in the southern Amazonia climate: a case study for the region of Alta Floresta, Mato Grosso, Brazil.

The transformation of forest into pastures in the Brazilian Amazon leads to significant consequences to climate at local scale. In the region of Alta Floresta (Mato Grosso, Brazil), deforestation has been intense with over half the forests being cut since 1970. This article first examines the evolution of precipitation observed in this region and shows a significant trend in the decrease in total precipitation especially at the end of the dry season and at the beginning of the rainy season. The study then compares the temperatures measured in cleared and forested sectors within a reserve in the area of Alta Floresta (Mato Grosso, Brazil) between 2006 and 2007. The cleared sector was always hotter and drier (from 5% to 10%) than the forested area. This difference was not only especially marked during the day when it reached on average 2°C but also seemed to increase during the night with the onset of the dry season (+0.5°C). The Urban Heat Island effect is also evident especially during the night and in the dry season.