| 1. |
- Amora-Nogueira, Leonardo, et al.
(författare)
-
Linking centennial scale anthropogenic changes and sedimentary records as lessons for urban coastal management
- 2023
-
Ingår i: Science of the Total Environment. - : ELSEVIER. - 0048-9697 .- 1879-1026. ; 902
-
Tidskriftsartikel (refereegranskat)abstract
- Coastal eutrophication and urban flooding are increasingly important components of global change. Although increased seawater renewal by barrier openings and channelizing are common mitigation measures in coastal lagoons worldwide, their effects on these ecosystems are not fully understood. Here, we evaluated the re-lationships between human interventions in the watershed, artificial connections to the sea, and the sediment burial rates in an urban coastal lagoon (Maric & PRIME;a lagoon, Southeastern Brazil). Sediment accretion along with nutrient and carbon burial rates were determined in two sediment cores representing the past-120 years (210Pb dating) and associated with anthropogenic changes as indicated by historical records and geoinformation ana-lyses. Lagoon infilling and eutrophication, expressed by the average sediment accretion, TP, TN, and OC burial rates, respectively, increased-9-18, 13-15, 11-14 and 11-12-fold from the earliest (<1950) to the most recent (2000-2017) period. These multi-proxy records confirm mechanistic links between deforestation, urbanization, and untreated sewage discharges. In addition, our findings reveal artificial connections to the sea may contribute to lagoonal eutrophication and infilling, particularly when not integrated with sewage treatment and forest conservation or reforestation in the watershed. Therefore, increased seawater renewal by physical interventions commonly considered as mitigation measures may in contrast cause severe degradation in coastal lagoons, causing harmful consequences that should be not neglected when implementing management practices.
|
|
| 2. |
- Householder, John Ethan, et al.
(författare)
-
One sixth of Amazonian tree diversity is dependent on river floodplains
- 2024
-
Ingår i: NATURE ECOLOGY & EVOLUTION. - 2397-334X. ; 8, s. 901-911
-
Tidskriftsartikel (refereegranskat)abstract
- Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.
|
|
| 3. |
- Luize, Bruno Garcia, et al.
(författare)
-
Geography and ecology shape the phylogenetic composition of Amazonian tree communities
- 2024
-
Ingår i: JOURNAL OF BIOGEOGRAPHY. - 0305-0270 .- 1365-2699. ; 51:7, s. 1163-1184
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and v & aacute;rzea forest types, the phylogenetic composition varies by geographic region, but the igap & oacute; and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R-2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R-2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions.
|
|
| 4. |
- Mendieta-Leiva, Glenda, et al.
(författare)
-
EpIG-DB: A database of vascular epiphyte assemblages in the Neotropics
- 2020
-
Ingår i: Journal of Vegetation Science. - : Wiley. - 1100-9233 .- 1654-1103. ; 31, s. 518-528
-
Tidskriftsartikel (refereegranskat)abstract
- Vascular epiphytes are a diverse and conspicuous component of biodiversity in tropical and subtropical forests. Yet, the patterns and drivers of epiphyte assemblages are poorly studied in comparison with soil-rooted plants. Current knowledge about diversity patterns of epiphytes mainly stems from local studies or floristic inventories, but this information has not yet been integrated to allow a better understanding of large-scale distribution patterns. EpIG-DB, the first database on epiphyte assemblages at the continental scale, resulted from an exhaustive compilation of published and unpublished inventory data from the Neotropics. The current version of EpIG-DB consists of 463,196 individual epiphytes from 3,005 species, which were collected from a total of 18,148 relevés (host trees and ‘understory’ plots). EpIG-DB reports the occurrence of ‘true’ epiphytes, hemiepiphytes and nomadic vines, including information on their cover, abundance, frequency and biomass. Most records (97%) correspond to sampled host trees, 76% of them aggregated in forest plots. The data is stored in a TURBOVEG database using the most up-to-date checklist of vascular epiphytes. A total of 18 additional fields were created for the standardization of associated data commonly used in epiphyte ecology (e.g. by considering different sampling methods). EpIG-DB currently covers six major biomes across the whole latitudinal range of epiphytes in the Neotropics but welcomes data globally. This novel database provides, for the first time, unique biodiversity data on epiphytes for the Neotropics and unified guidelines for future collection of epiphyte data. EpIG-DB will allow exploration of new ways to study the community ecology and biogeography of vascular epiphytes.
|
|
| 5. |
- Muscarella, Robert, et al.
(författare)
-
The global abundance of tree palms
- 2020
-
Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 29:9, s. 1495-1514
-
Tidskriftsartikel (refereegranskat)abstract
- AimPalms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change.LocationTropical and subtropical moist forests.Time periodCurrent.Major taxa studiedPalms (Arecaceae).MethodsWe assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co‐occurring non‐palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure.ResultsOn average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‐term climate stability. Life‐form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‐tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‐ground biomass, but the magnitude and direction of the effect require additional work.ConclusionsTree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests.
|
|
| 6. |
- ter Steege, Hans, et al.
(författare)
-
Mapping density, diversity and species-richness of the Amazon tree flora
- 2023
-
Ingår i: COMMUNICATIONS BIOLOGY. - 2399-3642. ; 6:1
-
Tidskriftsartikel (refereegranskat)abstract
- Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution. A study mapping the tree species richness in Amazonian forests shows that soil type exerts a strong effect on species richness, probably caused by the areas of these forest types. Cumulative water deficit, tree density and temperature seasonality affect species richness at a regional scale.
|
|
| 7. |
- Graco-Roza, Caio, et al.
(författare)
-
Distance decay 2.0 – A global synthesis of taxonomic and functional turnover in ecological communities
- 2022
-
Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 31:7, s. 1399-1421
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: Understanding the variation in community composition and species abundances (i.e., beta-diversity) is at the heart of community ecology. A common approach to examine beta-diversity is to evaluate directional variation in community composition by measuring the decay in the similarity among pairs of communities along spatial or environmental distance. We provide the first global synthesis of taxonomic and functional distance decay along spatial and environmental distance by analysing 148 datasets comprising different types of organisms and environments.Location: Global.Time period: 1990 to present.Major taxa studied: From diatoms to mammals.Method: We measured the strength of the decay using ranked Mantel tests (Mantel r) and the rate of distance decay as the slope of an exponential fit using generalized linear models. We used null models to test whether functional similarity decays faster or slower than expected given the taxonomic decay along the spatial and environmental distance. We also unveiled the factors driving the rate of decay across the datasets, including latitude, spatial extent, realm and organismal features.Results: Taxonomic distance decay was stronger than functional distance decay along both spatial and environmental distance. Functional distance decay was random given the taxonomic distance decay. The rate of taxonomic and functional spatial distance decay was fastest in the datasets from mid-latitudes. Overall, datasets covering larger spatial extents showed a lower rate of decay along spatial distance but a higher rate of decay along environmental distance. Marine ecosystems had the slowest rate of decay along environmental distances.Main conclusions: In general, taxonomic distance decay is a useful tool for biogeographical research because it reflects dispersal-related factors in addition to species responses to climatic and environmental variables. Moreover, functional distance decay might be a cost-effective option for investigating community changes in heterogeneous environments.
|
|
| 8. |
- Lamarca, Angela, et al.
(författare)
-
Tumour Growth Rate as a validated early radiological biomarker able to reflect treatment-induced changes in Neuroendocrine Tumours : the GREPONET-2 study
- 2019
-
Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 15:25, s. 6692-6699
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: TGR represents the percentage change in tumour volume per month (%/m). Previous results from the GREPONET study showed that TGR measured after 3 months (TGR3m) of starting systemic treatment (ST) or watch and wait (WW) was an early biomarker predicting progression-free survival (PFS) in NETs.EXPERIMENTAL DESIGN: Pts from7 centres with advanced grade(G) 1/2 NETs from the pancreas(P)/small bowel(SB) initiating ST/WW were eligible. Computed tomography (CT) / magnetic resonance imaging (MRI) performed at pre-baseline, baseline and 3(+/-1) months of study entry were retrospectively reviewed. Aim-1: explore treatment-induced changes in TGR (ΔTGR3m-BL) (paired T-test) and Aim-2: validate TGR3m (<0.8%/m vs ≥0.8%/m) as an early biomarker in an independent cohort (Kaplan-Meier/Cox Regression).RESULTS: Out of 785 pts screened, 127 were eligible. Mean (SD) TGR0 and TGR3m were 5.4%/m (14.9) and -1.4%/m (11.8), respectively. Mean(SD) ΔTGR3m-BL paired-difference was -6.8%/m(19.3) (p<0.001). Most marked ΔTGR3m-BL (mean (SD);p) were identified with targeted therapies (-11.3%/m(4.7);0.0237) and chemotherapy (-7.9%/m(3.4);0.0261). Multivariable analysis confirmed the absence of previous treatment (Odds Ratio (OR) 4.65 (95%CI 1.31-16.52); p-value0.018) and low TGR3m (continuous variable; OR 1.09 (95%CI 1.01-1.19); p-value0.042) to be independent predictors of radiological objective response. When the multivariable Cox Regression was adjusted to grade (p-value 0.004) and stage (p-value0.017), TGR3m≥0.8 (vs.<0.8) maintained its significance (p<0.001), while TGR0 and ΔTGR3m-BL did not. TGR3m was confirmed as an independent prognosis factor for PFS (external validation; Aim-2) (multivariable HR 2.21 (95%CI 1.21-3.70); p-value0.003).CONCLUSIONS: TGR has a role as biomarker for monitoring response to therapy for early prediction of PFS and radiological objective response.
|
|
| 9. |
- Neri, Luciana S S, et al.
(författare)
-
Blockade of vasopressin receptors reduces the threshold pressure of micturition reflex in female rats.
- 2022
-
Ingår i: Current research in physiology. - : Elsevier BV. - 2665-9441. ; 5, s. 399-403
-
Tidskriftsartikel (refereegranskat)abstract
- The mechanisms involved in urinary bladder control are not fully understood, but it is well accepted that a complex central network is involved in micturition control. The micturition reflex can be modulated by direct cortical influence through facilitatory and inhibitory mechanisms. In addition, humoral mechanisms are involved in the bladder control. Vasopressin increases bladder contraction and intravesical pressure. This study sought to investigate the effect of intravenous injections of vasopressin receptor antagonists on cystometric parameters in anesthetized female rats. Isoflurane anesthetized adult female Wistar rats underwent femoral artery and vein cannulation for arterial pressure (AP) and heart rate (HR) recordings, and infusion of drugs, respectively. The bladder was also cannulated for intravesical pressure (IP) recordings and infusion of saline (10mL/h) for cystometric evaluation. After baseline AP, HR and IP recordings, saline (vehicle, 1mL/kg), V1a (5μg/kg) or V2 receptor antagonist (5μg/kg) was injected i.v. and after 25min the cystometry was carried out. Neither saline nor V1a or V2 receptor blockade evoked any change in AP, HR and IP. Nevertheless, during cystometry, the threshold pressure of the micturition reflex was significantly reduced in rats with V1a (to 19.30±2.39mmHg) and V2 receptor blockade (to 19.88±2.49mmHg) compared to the saline group (28.85±2.06mmHg, p=0.014). No difference was observed in the other cystometric parameters. Therefore, the data suggest that blockade of V1a and V2 receptors reduces the threshold pressure of the micturition reflex and does not influence other cystometric parameters in anesthetized female Wistar rats.
|
|
| 10. |
- Rampazzo, Roberto, et al.
(författare)
-
Extragalactic Astronomy : From Pioneers to Big Science
- 2016
-
Ingår i: From the Realm of the Nebulae to Populations of Galaxies. - Cham : Springer. - 9783319310046 - 9783319310060 ; , s. 1-92
-
Bokkapitel (refereegranskat)abstract
- At the beginning of the nineteenth century one of the scientific issues driving the research of astronomers, like the Herschels, was to test if all the nebulæ can be resolved into stars.
|
|
