The effects of a disturbance by sandbar opening on the zooplankton community were evaluated through a long-term study in an eutrophic and oligohaline system, Imboassica Lagoon, Rio de Janeiro, Brazil. Zooplankton samples and limnological data were collected monthly from March 2000 to February 2003. Before the sandbar was opened in February 2001, the lagoon showed eutrophic conditions, with high mean nutrient concentrations and low salinity (total nitrogen – TN = 190.28 μM, chlorophyll a content – Chl. a = 104.60 μg/L and salinity = 0.87′). During this period, the zooplankton species present, such as the rotifers Brachionus calyciflorus and Brachionus havanaensis, were typical of freshwater to oligohaline and eutrophic environments. After the sandbar opening, the lagoon changed to a lower trophic status and increased salinity (TN = 55.11 μM, Chl. a = 27.56 μg/L and salinity = 19.64′). As a result, the zooplankton community came to consist largely of the rotifer Brachionus plicatilis, marine copepods and meroplanktonic larvae, mainly Gastropoda. Salinity was the main force structuring the zooplankton community after the sandbar opening. Two years after this episode, the prior zooplankton community had not reestablished itself, indicating a low resilience to this disturbance. The conditions developed prior to a sandbar opening can be crucial to the community responses in the face of this disturbance and for the capacity of the original zooplankton community to re-establish itself. 相似文献
Monitoring coral reef communities at a decadal scale is necessary to understand and project their dynamics to provide a basis for reef management in light of disturbances and climate change. Complementing infrequent and localised in situ observations, time-series of aerial photographs and remotely sensed satellite images provide a means of monitoring the position and extent of reef-top coral communities, vegetation and abiotic substrata at the whole reef scale. The aim of the present study was to map such changes on Saint-Leu Reef (La Réunion) between 1973 and 2007. The period included two cyclones (1989, 2002) and one severe bleaching event (2002). Vertical images of the reef were recorded in five aerial photographs (1973, 1978, 1989, 1997, and 2003) and two Quickbird satellite images (2002, 2006) during that time. Quantitative in situ observations of parts of the reef-top were also available both to document ecological and substratum characteristics that produce the color and texture observable in the photos and satellite images. Coral communities were mapped on all images using manual delineation of polygons identified according to color and texture contrast. The 2006 Quickbird image was used as the mapping base and 15 types of coral communities were identified from a reef survey conducted in 2007. This hierarchical typology used coral growth forms, live and dead coral cover, macro-algae, substratum (sand, rubble and platform) and, to a lesser extent, coral taxonomy. The polygons at date t were over-laid onto image t − 1 across the whole series and their boundaries were manually edited to match the pattern on the earlier image. Labelling of polygons was guided by field-survey data and maps. For coral-dominated patches, six successive pairs of maps from 1973 to 2006 were compared to produce ‘coral community change maps’ for that period. Despite the multiple disturbance events, the coral community distribution and composition in 2006 on Saint-Leu Reef did not display major differences compared to 1973. This suggests a high degree of coral resilience at the site, led by rapid recovery of compact branching corals. The mapping techniques overcame challenges due to different image quality and the sparsity of in situ observations in time and space. Our results demonstrate the potential for further application of reef monitoring protocols based on complementary in situ and remote-sensing data to help understand the dynamics of reef-top coral reef communities and geomorphology over years to decades. 相似文献
We live in a rapidly advancing digital information age where the ability to discover, access and utilize high-quality information in a reliable and timely manner is often assumed to be the norm. However, this is not always the experience of researchers, practitioners and decision makers responding to the challenges of a rapidly changing climate, despite the billions now being made available for investment in climate change adaptation initiatives throughout the world and particularly in developing countries. In recognition of the importance of information in adaptation planning, Article 7.7 of the Paris Agreement sets out clear guidance for parties to develop, share, manage and deliver climate change knowledge, information and data as a means to strengthening cooperation and action on adaptation. This article provides some key lessons and insights on climate change information and knowledge management (IKM) in small island developing States (SIDS) from the perspective of Pacific SIDS. A situation analysis of current climate change IKM practices in Fiji, Tonga and Vanuatu was conducted and key barriers to effective climate change IKM identified. The outcome of this article is a range of pragmatic policy considerations for overcoming common barriers to climate change IKM in the Pacific, which may be of value to SIDS more widely.
Key policy insights
The partnership approach of co-investigating climate change IKM barriers in collaboration with Pacific SIDS generated considerable trust, a shared purpose and therefore rich IKM lessons and insights.
Turning climate change IKM aspirations into practice is significantly more complicated than expected, and requires a long-term commitment from both national governments and development partners.
Pacific SIDS need to establish national guiding climate change IKM Frameworks that leverage rather than duplicate growing national investments in whole-of-government IKM.
Reframing climate change IKM in the Pacific towards demand and user needs will be critical to ensuring widespread ownership and participation in IKM solutions that lead to greater adaptation and resilience outcomes.
It is also critical that IKM activities in SIDS support the development of national capacity to scope, develop, deploy and maintain decision support systems.
Federated IKM systems are ideal for encouraging greater IKM collaboration.
Climate change is projected to increase the frequency, intensity and unpredictability of extreme weather events across the globe and these events are likely to have significant mental health implications. The mental health literature broadly characterises negative emotional reactions to extreme weather experiences as undesirable impacts on wellbeing. Yet, other research in psychology suggests that negative emotional responses to extreme weather are an important motivation for personal action on climate change. This article addresses the intersection of mental health and functional perspectives on negative emotions, with a specific focus on the potential that reduced negative emotional responses to extreme weather may also translate to diminished motivation to undertake climate change mitigation actions – which we term the ‘resilience paradox’. Using survey data gathered in the aftermath of severe flooding across the UK in winter 2013/2014, we present new evidence indicating that self-appraised coping ability moderates the link between flooding experience and negative emotions and thereby attenuates the indirect link between flooding experience and climate change mitigation intentions. We conclude that support for flood victims should extend beyond addressing emotional, physical and financial stresses to include acknowledgement of the involvement of climate change and communication of the need for action to combat future climate risks.
Key policy insights
Psychological resilience to flooding and other extreme weather events can translate to diminished motivation to mitigate climate change
Negative emotional reactions need to occur at an optimal level to enable people to respond appropriately to climate risks.
Flood victims’ subjective appraisal of their ability to cope does not necessarily encompass consideration of the role played by climate change. Therefore, support for victims of extreme weather should include explicit acknowledgement of the involvement of climate change and the need for action to mitigate future climate risks.