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This study presents two years of characterization of a warm temperate rhodolith bed in order to analyse how certain environmental changes influence the community ecology. The biomass of rhodoliths and associated species were analysed during this period and in situ experiments were conducted to evaluate the primary production, calcification and respiration of the dominant species of rhodoliths and epiphytes. The highest total biomass of rhodoliths occurred during austral winter. Lithothamnion crispatum was the most abundant rhodolith species in austral summer. Epiphytic macroalgae occurred only in January 2015, with Padina gymnospora being the most abundant. Considering associated fauna, the biomass of Mollusca increased from February 2015 to February 2016. Population densities of key reef fish species inside and around the rhodolith beds showed significant variations in time. The densities of grouper (carnivores/piscivores) increased in time, especially from 2015 to 2016. On the other hand, grunts (macroinvertebrate feeders) had a modest decrease over time (from 2014 to 2016). Other parameters such as primary production and calcification of L. crispatum were higher under enhanced irradiance, yet decreased in the presence of P. gymnospora. Community structure and physiological responses can be explained by the interaction of abiotic and biotic factors, which are driven by environmental changes over time. Biomass changes can indicate that herbivores play a role in limiting the growth of epiphytes, and this is beneficial to the rhodoliths because it decreases competition for environmental resources with fleshy algae. Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) [407365/2013-3] Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) CNPqConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) [302604/2015-4] FAPES (Fundacao de Amparo a Pesquisa e Inovacao do Espirito Santo, Brazil)/CAPES [10/2018] info:eu-repo/semantics/publishedVersion

Submitted by Filipa Custódio (fccustodio@ualg.pt) on 2021-03-17T14:45:28Z No. of bitstreams: 1 Golden carbon of Sargassum forests revealed as an opportunity for climate change mitigation (vol 729, 138745, 2020).pdf: 712913 bytes, checksum: 65d45c4c25a3968a0fba20f640cdaf01 (MD5) Approved for entry into archive by Carla Janeira (cjaneira@ualg.pt) on 2021-03-18T10:04:17Z (GMT) No. of bitstreams: 1 Golden carbon of Sargassum forests revealed as an opportunity for climate change mitigation (vol 729, 138745, 2020).pdf: 712913 bytes, checksum: 65d45c4c25a3968a0fba20f640cdaf01 (MD5) Made available in DSpace on 2021-03-18T10:04:17Z (GMT). No. of bitstreams: 1 Golden carbon of Sargassum forests revealed as an opportunity for climate change mitigation (vol 729, 138745, 2020).pdf: 712913 bytes, checksum: 65d45c4c25a3968a0fba20f640cdaf01 (MD5) Previous issue date: 2021 info:eu-repo/semantics/publishedVersion

Marine climate change mitigation initiatives have recently attracted a great deal of interest in the role of natural carbon sinks, particularly on coastal systems. Brown seaweeds of the genus Sargassum are the largest canopyforming algae in tropical and subtropical environments, with a wide global distribution on rocky reefs and as floating stands. Because these algae present high amounts of biomass, we suggest their contribution is relevant for global carbon stocks and consequently for mitigating climate change as CO2 remover. We modelled global distributions and quantified carbon stocks as above-ground biomass (AGB) with machine learning algorithms and climate data. Sargassum AGB totaled 13.1 Pg C at the global scale, which is a significant amount of carbon, comparable to other key marine ecosystems, such as mangrove forests, salt marshes and seagrass meadows. However, specific techniques related to bloom production and management, or the utilization of biomass for biomaterials, should be fostered. SFRH/BSAB/150485/2019, DL57/2016/CP1361/CT0035, UIDB/04326/2020, EMBRC.PT ALG-01-0145-FEDER-022121, 88882.438723/2019-01, 310793/2018-01, 407365/2013-3, 426215/2016-8, CNPq-PQ-308537/2019-0 info:eu-repo/semantics/publishedVersion

The “CFH Forest” is a green area of five hectares in the UFSC campus, which shelters areas for permanent preservation of riparian forest and remaining of native vegetation. Besides the ecological function, area is a living space for university community. Over the years, the use and occupation of this area have caused negative environmental impact, generating erosion, compaction and loss of soil organic matter, leading to increased environmental degradation. The Agroecological Agroforestry Systems (Agroecological AFS) have been considered as an alternative approach for environmental recovery as it promotes efficiency and optimization of natural resources for production in an integrated form. This article aims to report the experience of this recovery project within the university campus, using Agroecological AFS, along with the principles of permaculture and the concept of energetic zones, through the “CFH Forest Environmental Recovery Project”, with students, teachers and technicians participation. After two years of project execution, some results are already visible, such as vegetation growth, soil recovery, erosion control and improvement of ecological awareness through education, stimulated by workshops, joint efforts and the promotion of a healthier environment.

Rhodolith beds are important marine benthic ecosystems, representing oases of high biodiversity among sedimentary seabed environments. They are found frequently and abundantly, acting as major carbonate 'factories' and playing a key role in the biogeochemical cycling of carbonates in the South Atlantic. Rhodoliths are under threat due to global change (mainly related to ocean acidification and global warming) and local stressors, such as fishing and coastal run-off. Here, we review different aspects of the biology of these organisms, highlighting the predicted effects of global change, considering the additional impact of local stressors. Ocean acidification (OA) represents a particular threat that can reduce calcification or even promote the decalcification of these bioengineers, thus increasing the eco-physiological imbalance between calcareous and fleshy algae. OA should be considered, but this together with extreme events such as heat waves and storms, as main stressors of these ecosystems at the present time, will worsen in the future, especially if possible interactions with local stressors like coastal pollution are taken into consideration. Thus, in Brazil there is a serious need for starting monitoring programs and promote innovative experimental infrastructure in order to improve our knowledge of these rich environments, optimize management efforts and enhance the needed conservation initiatives. Resumo Bancos de rodolitos formam oásis de alta biodiversidade em ambientes marinhos de fundo arenoso. Os rodolitos são formados por espécies bioconstrutoras, que fornecem abrigo e substrato para diversas e abundantes comunidades bentônicas. No Brasil esses ambientes são frequentes, representando grandes "fábricas" de carbonato com um papel fundamental no ciclo biogeoquímico do carbono no Atlântico Sul. Estes organismos e ambientes estão ameaçados pelas mudanças climáticas (principalmente a acidificação dos oceanos e o aquecimento global) e pelos estressores locais, tais como os impactos causados pela pesca e as descargas costeiras de efluentes. Neste trabalho fazemos uma revisão da taxonomia, filogenia e biologia desses organismos, com destaque para os efeitos previstos das mudanças climáticas e suas relações com estressores locais. A maioria dos estudos acerca dos efeitos das mudanças climáticas e da acidificação dos oceanos em algas calcárias relatam respostas negativas não só no crescimento e na calcificação, mas também no processo de fotossíntese, espessura da parede celular, reprodução e sobrevivência das algas. Este cenário reforça a necessidade em estabelecer uma consistente rede de trabalho para proporcionar um programa de monitoramento amplo e de longo prazo, bem como infraestrutura para avaliações experimentais de impactos locais e regionais das mudanças climáticas e dos estressores locais em bancos de rodolitos.