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991.
Jamie L. Wright Barbara Bomfim Corrine I. Wong Ben H. Marimon‐Júnior Beatriz S. Marimon Lucas C. R. Silva 《Global Change Biology》2021,27(1):136-150
Tropical ecosystems are under increasing pressure from land‐use change and deforestation. Changes in tropical forest cover are expected to affect carbon and water cycling with important implications for climatic stability at global scales. A major roadblock for predicting how tropical deforestation affects climate is the lack of baseline conditions (i.e., prior to human disturbance) of forest–savanna dynamics. To address this limitation, we developed a long‐term analysis of forest and savanna distribution across the Amazon–Cerrado transition of central Brazil. We used soil organic carbon isotope ratios as a proxy for changes in woody vegetation cover over time in response to fluctuations in precipitation inferred from speleothem oxygen and strontium stable isotope records. Based on stable isotope signatures and radiocarbon activity of organic matter in soil profiles, we quantified the magnitude and direction of changes in forest and savanna ecosystem cover. Using changes in tree cover measured in 83 different locations for forests and savannas, we developed interpolation maps to assess the coherence of regional changes in vegetation. Our analysis reveals a broad pattern of woody vegetation expansion into savannas and densification within forests and savannas for at least the past ~1,600 years. The rates of vegetation change varied significantly among sampling locations possibly due to variation in local environmental factors that constrain primary productivity. The few instances in which tree cover declined (7.7% of all sampled profiles) were associated with savannas under dry conditions. Our results suggest a regional increase in moisture and expansion of woody vegetation prior to modern deforestation, which could help inform conservation and management efforts for climate change mitigation. We discuss the possible mechanisms driving forest expansion and densification of savannas directly (i.e., increasing precipitation) and indirectly (e.g., decreasing disturbance) and suggest future research directions that have the potential to improve climate and ecosystem models. 相似文献
992.
Brett Jestrow William Cinea Brígido Peguero Chad Husby Javier Francisco‐Ortega 《Curtis's Botanical Magazine》2021,38(1):3-18
Clavija domingensis Urb. & Ekman was one of the many Haitian endemics that were described based on collections made by the great Swedish botanist Leonard Ekman between 1924 and 1928. The species is Critically Endangered sensu IUCN (criteria c2a(i); D) and it is currently the focus of conservation initiatives in Jardin Botanique des Cayes (Haiti), Jardín Botánico Nacional Dr. Rafael M. Moscoso (Dominican Republic), and Fairchild Tropical Botanic Garden (U.S.A.). Now known from only six localities from southern Haiti, each locality only represents a single individual. The species is illustrated based on plants grown in Fairchild Tropical Botanic Garden. 相似文献
993.
Chen Ping Dai Chun-Hua Shi Zhi-Hao Wang Yi Wu Jian-Nong Chen Kang Su Jin-Yu Li Jian 《Apoptosis : an international journal on programmed cell death》2021,26(11-12):639-656
Apoptosis - Resistance to epidermal growth factor receptor-tyrosin kinase inhibitors (TKIs, e.g. icotinib) remains a major clinical challenge. Non-small cell lung cancer patients with wild-type... 相似文献
994.
995.
Elizabeth A. Sinclair Craig D. H. Sherman John Statton Craig Copeland Andrew Matthews Michelle Waycott Kor‐Jent van Dijk Adriana Vergs Lana Kajlich Ian M. McLeod Gary A. Kendrick 《Ecological Management & Restoration》2021,22(1):10-21
Three case studies involving two temperate Australian seagrass species – Pondweed (Ruppia tuberosa) and Ribbon Weed (Posidonia australis) – highlight different approaches to their restoration. Seeds and rhizomes were used in three collaborative programmes to promote new approaches to scale up restoration outcomes. 相似文献
996.
Rosalind J. Dodd David R. Chadwick Ian M. Harris Adrian Hines Dan Hollis Theodoros Economou Dylan Gwynn‐Jones John Scullion David A. Robinson David L. Jones 《Ecology letters》2021,24(1):60-72
Extreme weather events have become a dominant feature of the narrative surrounding changes in global climate with large impacts on ecosystem stability, functioning and resilience; however, understanding of their risk of co‐occurrence at the regional scale is lacking. Based on the UK Met Office’s long‐term temperature and rainfall records, we present the first evidence demonstrating significant increases in the magnitude, direction of change and spatial co‐localisation of extreme weather events since 1961. Combining this new understanding with land‐use data sets allowed us to assess the likely consequences on future agricultural production and conservation priority areas. All land‐uses are impacted by the increasing risk of at least one extreme event and conservation areas were identified as the hotspots of risk for the co‐occurrence of multiple event types. Our findings provide a basis to regionally guide land‐use optimisation, land management practices and regulatory actions preserving ecosystem services against multiple climate threats. 相似文献
997.
Daniel Paredes Jay A. Rosenheim Rebecca Chaplin‐Kramer Silvia Winter Daniel S. Karp 《Ecology letters》2021,24(1):73-83
Diversifying agricultural landscapes may mitigate biodiversity declines and improve pest management. Yet landscapes are rarely managed to suppress pests, in part because researchers seldom measure key variables related to pest outbreaks and insecticides that drive management decisions. We used a 13‐year government database to analyse landscape effects on European grapevine moth (Lobesia botrana) outbreaks and insecticides across c. 400 Spanish vineyards. At harvest, we found pest outbreaks increased four‐fold in simplified, vineyard‐dominated landscapes compared to complex landscapes in which vineyards are surrounded by semi‐natural habitats. Similarly, insecticide applications doubled in vineyard‐dominated landscapes but declined in vineyards surrounded by shrubland. Importantly, pest population stochasticity would have masked these large effects if numbers of study sites and years were reduced to typical levels in landscape pest‐control studies. Our results suggest increasing landscape complexity may mitigate pest populations and insecticide applications. Habitat conservation represents an economically and environmentally sound approach for achieving sustainable grape production. 相似文献
998.
Mark E. Corkins Vanja Krneta‐Stankic Malgorzata Kloc Rachel K. Miller 《Genesis (New York, N.Y. : 2000)》2021,59(1-2):e23410
Cilia are microtubule‐based structures that either transmit information into the cell or move fluid outside of the cell. There are many human diseases that arise from malfunctioning cilia. Although mammalian models provide vital insights into the underlying pathology of these diseases, aquatic organisms such as Xenopus and zebrafish provide valuable tools to help screen and dissect out the underlying causes of these diseases. In this review we focus on recent studies that identify or describe different types of human ciliopathies and outline how aquatic organisms have aided our understanding of these diseases. 相似文献
999.
Gao Kai Liu Meiyou Li Yuan Wang Lei Zhao Chao Zhao Xian Zhao Jinyi Ding Yi Tang Haifeng Jia Yanyan Wang Jingwen Wen Aidong 《Journal of molecular histology》2021,52(3):449-459
Journal of Molecular Histology - Currently, the excessive activation of N-methyl-D-aspartate receptors (NMDARs) is considered to be a crucial mechanism of brain injury. Lycium barbarum A (LyA) is a... 相似文献
1000.
Plasmonics - Tunable local surface plasmon resonance (LSPR) enhancement properties of cavity-nanoparticle scaffold-based clusters were investigated via finite-difference time-domain (FDTD)... 相似文献