scholarly journals Patterns of Distribution of Bivalve Populations in a Mediterranean Temporary River

Diversity ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 158
Author(s):  
Mafalda Gama ◽  
Filipe Banha ◽  
Cristina Moreira ◽  
Henrique Gama ◽  
Manuel Graça ◽  
...  
Keyword(s):  
Climate Change ◽  
New Species ◽  
Vegetation Cover ◽  
Riparian Vegetation ◽  
Corbicula Fluminea ◽  
Sediment Types ◽  
Additional Challenge ◽  
Temporary River ◽  
Fine Gravel ◽  
Unio Delphinus

In the south of the Iberian Peninsula, many rivers are intermittent, a state most likely to be exacerbated by climate change, strongly affecting river biota. An additional challenge for native biota in this area is the arrival of new species, frequently aided by humans, and bivalves are particularly at risk. Here we assessed whether the native (Unio delphinus) and invasive (Corbicula fluminea) bivalves differed in habitat use. To address this question, we sampled populations of both species in six isolated permanent pools in the same river during summer in three consecutive years. U. delphinus occurred in all pools, while C. fluminea occurred only in the two most downstream pools. U. delphinus, but not C. fluminea, was found preferentially in patches under riparian vegetation cover. Both species were found in similar sediment types (coarse and fine gravel respectively). Although U. delphinus was present in all pools, recruitment was detected only in 2016, in one pool. We concluded that both species have the potential to compete for space, but a well-developed riparian vegetation cover may provide U. delphinus some advantage against C. fluminea.

Five new deep-sea species of nudibranchs (Gastropoda: Heterobranchia: Cladobranchia) from the Northeast Pacific

Zootaxa ◽  
2018 ◽  
Vol 4526 (4) ◽  
pp. 401 ◽  
Author(s):  
ÁNGEL VALDÉS ◽  
LONNY LUNDSTEN ◽  
NERIDA G. WILSON
Keyword(s):  
Climate Change ◽  
New Species ◽  
Deep Sea ◽  
Undescribed Species ◽  
Invertebrate Community ◽  
Nuclear Markers ◽  
Mitochondrial Coi ◽  
Northeast Pacific ◽  
Northeastern Pacific ◽  
System Information

Increased exploration of northeastern Pacific deep-sea habitats has revealed a diverse and often poorly-known invertebrate community, including a number of undescribed species of nudibranchs studied herein. We used morphology to distinguish several new species from their congeners, and generated data where possible for mitochondrial (COI, 16S) and nuclear markers (H3) to place them in a phylogenetic context. We described here Tritonia nigritigris sp. nov., Dendronotus claguei sp. nov., Ziminella vrijenhoeki sp. nov., Cuthona methana sp. nov., Aeolidia libitinaria sp. nov. and redescribed Zeusia herculea (Bergh, 1894). Another species of Tritonia is described but not named due to the absence of reproductive system information. Although there are difficulties in collection from deep-sea habitats, only two of our new species are known from single specimens. As with many other deep-sea regions, we expect the number of new species from this region to increase with further exploration. Because the deep regions of the northeast Pacific are particularly vulnerable to the effects of decreasing oxygenation due to climate change, we consider that documenting this fauna has some level of urgency. 

scholarly journals Effects of increased flooding on riparian vegetation: Field experiments simulating climate change along five European lowland streams

2017 ◽  
Vol 23 (8) ◽  
pp. 3052-3063 ◽  
Author(s):  
Annemarie G. Garssen ◽  
Annette Baattrup-Pedersen ◽  
Tenna Riis ◽  
Bart M. Raven ◽  
Carl Christian Hoffman ◽  
...  
Keyword(s):  
Climate Change ◽  
Riparian Vegetation ◽  
Field Experiments ◽  
Lowland Streams

Riparian Vegetation Dynamic and River Stability on Intermittent Rivers: Impact of Water Transfer Project on Tropical Drylands

2021 ◽  
Author(s):  
Camilla Santos ◽  
Leonardo Dantas Martins ◽  
Kenia Sousa da Cruz ◽  
Jonas Otaviano Praça de Souza
Keyword(s):  
Vegetation Cover ◽  
Riparian Vegetation ◽  
Google Earth ◽  
Water Transfer ◽  
Lateral Stability ◽  
Hydrological Changes ◽  
Vertical Incision ◽  
Short Period ◽  
Geomorphic Units ◽  
The Impact

<p>Rivers on semiarid landscapes typically are characterised by sandy geomorphic units and riverbanks, a natural factor that enhances lateral mobility. Vegetation cover is a crucial factor on lateral instability due to its impact on riverbank and geomorphic units erosion resistance. Nevertheless, riparian vegetation on intermittent and ephemeral channels show growing patterns directly affect by the flow temporality, that controls the water availability. Extended dry intervals hinder the succession ecological on geomorphic units, like bars and islands, and riverbanks and retard the growing process. This work analysed the effects of hydrological changes, caused by one water transfer project, on the bio-geomorphological patterns on riverbanks of a main intermittent river of Brazilian Drylands. Flow data series was used to understand the hydrological pattern changes; Google Earth images and UAV surveys to analyse the vegetation and riverbank behaviour from 2008 to 2020.  Lastly, the identification of riverbank material resistance was based on sedimentology analysis.  The water transfer Project PISF (Projeto de Integração do São Francisco), operating since 2017 March, increase the average flow days from 137,5 to 260/300 days and decreasing the continuous dry period from 200 to 30/45 days. The impact on average annual discharge was slightest, whereas the average water transfer volume was 3m<sup>3</sup>/s. It is essential to highlight the short period of data posterior to the water transfer and the non-regulatiry of water volume transferred; what limits the temporal representativity of the results. There were different types, and level of impacts depending on the river reach characteristics. However, in general, the longer flow permanence increases riparian vegetation density, vertical incision, and lateral stability. Riparian vegetation cover increase, from 20% to 100% on the 9 reaches analysed, across the entire channel, including bedrock reaches, with riverbanks having some rock outcrops percentage. The main changes were on sand bed reaches, that used to have, before 2017, a dynamic braiding pattern, without a clear main incised channel and thalweg shifting. Afterwards, the flow permanence, due to the water transfer project, enabled herbaceous stratus temporal continuity, contributing to surface stability and progressive bushes/trees cover growing. Lastly, the increase in lateral stability, mainly on thalweg position, facilitates the vertical incision on the sand bed reaches, representing 85% of this channel. As a secondary impact, there were necessary, to the road network, built floodway crossings at several points, which changes the channel morphology and the (dis)connectivity process. It can generate distinct channel position and morphology changes causing water and sediment retention upstream and erosion downstream. Lastly, there were slight differences in textural characteristics on riverbanks and geomorphic units, with a rise in fine sediment on the most vegetated areas/units. This analysis reveals that a fast response of riparian vegetation and sand bed reaches morphology, affecting the bio-geomorphological process and all environmental dynamic. It points to fundamental elements which need monitoring after hydrological changes, especially to intermittent and ephemeral rivers.</p>

Human Destinies

2018 ◽  
pp. 73-92
Author(s):  
Gary Westfahl
Keyword(s):  
Climate Change ◽  
New Species ◽  
Science Fiction ◽  
Human Development ◽  
Interstellar Space ◽  
Fiction Writers ◽  
The City ◽  
A New Species

Unlike other science fiction writers, this chapter explains, Clarke rarely envisions humanity colonizing interstellar space and forging a galactic empire, anticipating limitations on human development. Though unconcerned about nuclear wars or alien invasions, Clarke regularly predicts humanity’s extinction, due to climate change or competing new species, or long periods of decadence. If humans avoid these fates, evolution may transform them into a new species, unlike present-day humans. Such scenarios unfold in Clarke’s major novels about humanity’s destiny: in Against the Fall of Night (1953), revised as The City and the Stars (1956), residents of an unchanging future city rediscover their ambitions but still face eventual demise; and in Childhood’s End (1953) humans guided by alien Overlords become a group intelligence to join a transcendent Overmind.

scholarly journals Associations between fish assemblage and riparian vegetation in the Corumbataí River Basin (SP)

2007 ◽  
Vol 67 (2) ◽  
pp. 191-195 ◽  
Author(s):  
M. Cetra ◽  
M. Petrere JR.
Keyword(s):  
Species Richness ◽  
River Basin ◽  
Fish Species ◽  
Sugar Cane ◽  
Fish Assemblage ◽  
Vegetation Cover ◽  
Riparian Vegetation ◽  
Riparian Forest ◽  
The State ◽  
Multivariate Techniques

This work intends to examine if there are associations between fish species and the state of conservation of the riparian forest in the Corumbataí River Basin. Four main rivers were chosen for this study with three sites on each. Collections were carried out from March to June and from September to December 2001. Multivariate techniques were applied to determine the correlation between species richness and the order of the rivers, preservation level of the riparian forest, shade level, presence or absence of Eucalyptus, sugar cane and pastures, and surrounding declivity stability of the sites. Species richness was highest at locations with greater vegetation cover and preserved riparian forest.

scholarly journals Influence of Different Satellite Imagery on the Analysis of Riparian Leaf Density in a Mountain Stream

2020 ◽  
Vol 12 (20) ◽  
pp. 3376 ◽  
Author(s):  
Giovanni Romano ◽  
Giovanni Francesco Ricci ◽  
Francesco Gentile
Keyword(s):  
Winter Wheat ◽  
Satellite Imagery ◽  
Vegetation Cover ◽  
Riparian Vegetation ◽  
Deciduous Forests ◽  
Sensor Data ◽  
Mountain Stream ◽  
Landsat 8 ◽  
Area Index ◽  
Sentinel 2

In recent decades, technological advancements in sensors have generated increasing interest in remote sensing data for the study of vegetation features. Image pixel resolution can affect data analysis and results. This study evaluated the potential of three satellite images of differing resolution (Landsat 8, 30 m; Sentinel-2, 10 m; and Pleiades 1A, 2 m) in assessing the Leaf Area Index (LAI) of riparian vegetation in two Mediterranean streams, and in both a winter wheat field and a deciduous forest used to compare the accuracy of the results. In this study, three different retrieval methods—the Caraux-Garson, the Lambert-Beer, and the Campbell and Norman equations—are used to estimate LAI from the Normalized Difference Vegetation Index (NDVI). To validate sensor data, LAI values were measured in the field using the LAI 2200 Plant Canopy Analyzer. The statistical indices showed a better performance for Pleiades 1A and Landsat 8 images, the former particularly in sites characterized by high canopy closure, such as deciduous forests, or in areas with stable riparian vegetation, the latter where stable reaches of riparian vegetation cover are almost absent or very homogenous, as in winter wheat fields. Sentinel-2 images provided more accurate results in terms of the range of LAI values. Considering the different types of satellite imagery, the Lambert-Beer equation generally performed best in estimating LAI from the NDVI, especially in areas that are geomorphologically stable or have a denser vegetation cover, such as deciduous forests.

Riparian vegetation responses to altered flow regimes driven by climate change in Mediterranean rivers

Ecohydrology ◽  
2012 ◽  
Vol 6 (3) ◽  
pp. 413-424 ◽  
Author(s):  
Rui Rivaes ◽  
Patricia M. Rodríguez-González ◽  
António Albuquerque ◽  
António N. Pinheiro ◽  
Gregory Egger ◽  
...  
Keyword(s):  
Climate Change ◽  
Riparian Vegetation ◽  
Flow Regimes ◽  
Mediterranean Rivers ◽  
Vegetation Responses

New synonymies in the plant bug family Miridae (Hemiptera: Heteroptera) from Northern China

Zootaxa ◽  
2016 ◽  
Vol 4205 (5) ◽  
pp. 496 ◽  
Author(s):  
FEDOR V. KONSTANTINOV
Keyword(s):  
Climate Change ◽  
New Species ◽  
Central Asia ◽  
Northern China ◽  
Common Species ◽  
Northwestern China ◽  
Future Studies ◽  
Generic Composition ◽  
Chinese Plant ◽  
Tertiary Period

The plant bug fauna of China is highly diverse and relatively poorly documented, with almost 900 currently known species, about a half of which had been revealed during the last two decades (Qi et al. 2003, 2007, Konstantinov & Namyatova 2008, 2009, Konstantinov et al. 2013). Future studies would almost certainly reveal many new species from the region. However, the present day distributions of Chinese plant bugs apparently reflect significant climate change since the Tertiary Period, and are largely influenced by influx of species from other regions. Particularly, the plant bug fauna of the Northwestern China is most similar to the faunas of Central Asia and Mongolia, having almost identical generic composition and sharing many common species (Kerzhner & Josifov 1999). This paper provides seven new synonymies of Miridae originally known from Central Asia and Mongolia and recently described as new from the Northern China. 

scholarly journals Quantifying the Impacts of Anthropogenic Activities and Climate Variations on Vegetation Productivity Changes in China from 1985 to 2015

2020 ◽  
Vol 12 (7) ◽  
pp. 1113
Author(s):  
Shahid Naeem ◽  
Yongqiang Zhang ◽  
Jing Tian ◽  
Faisal Mueen Qamer ◽  
Aamir Latif ◽  
...  
Keyword(s):  
Climate Change ◽  
Primary Productivity ◽  
Human Activities ◽  
Vegetation Cover ◽  
Net Primary Productivity ◽  
Anthropogenic Activities ◽  
Climate Factors ◽  
Climate Variations ◽  
Base Period ◽  
Increasing Trends

Accurate assessment of vegetation dynamics provides important information for ecosystem management. Anthropogenic activities and climate variations are the major factors that primarily influence vegetation ecosystems. This study investigates the spatiotemporal impacts of climate factors and human activities on vegetation productivity changes in China from 1985 to 2015. Actual net primary productivity (ANPP) is used to reflect vegetation dynamics quantitatively. Climate-induced potential net primary productivity (PNPP) is used as an indicator of climate change, whereas the difference between PNPP and ANPP is considered as an indicator of human activities (HNPP). Overall, 91% of the total vegetation cover area shows declining trends for net primary productivity (NPP), while only 9% shows increasing trends before 2000 (base period). However, after 2000 (restoration period), 78.7% of the total vegetation cover area shows increasing trends, whereas 21.3% of the area shows decreasing trends. Moreover, during the base period, the quantitative contribution of climate change to NPP restoration is 0.21 grams carbon per meter square per year (gC m−2 yr−1) and to degradation is 2.41 gC m−2 yr−1, while during the restoration period, climate change contributes 0.56 and 0.29 gC m−2 yr−1 to NPP restoration and degradation, respectively. Human activities contribute 0.36 and 0.72 gC m−2 yr−1 during the base period, and 0.63 and 0.31 gC m−2 yr−1 during the restoration period to NPP restoration and degradation, respectively. The combined effects of climate and human activities restore 0.65 and 1.11 gC m−2 yr−1, and degrade 2.01 and 0.67 gC m−2 yr−1 during the base and restoration periods, respectively. Climate factors affect vegetation cover more than human activities, while precipitation is found to be more sensitive to NPP change than temperature. Unlike the base period, NPP per unit area increases with an increase in the human footprint pressure during the restoration period. Grassland has more variability than other vegetation classes, and the grassland changes are mainly observed in Tibet, Xinjiang, and Inner Mongolia regions. The results may help policy-makers by providing necessary guidelines for the management of forest, grassland, and agricultural activities.

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