Patterns of abundance and size of Dictyoceratid sponges among neighbouring islands in central Torres Strait, Australia

2007 ◽  
Vol 58 (2) ◽  
pp. 204 ◽  
Author(s):  
Alan R. Duckworth ◽  
Carsten W. Wolff
Keyword(s):  
Spatial Scales ◽  
Distribution Patterns ◽  
Small Scale ◽  
Size Frequency Distribution ◽  
Abundance Patterns ◽  
Size Frequency ◽  
Dysidea Herbacea ◽  
Torres Strait ◽  
Study Sites ◽  
Species Specific

Distribution and size frequency patterns of sessile organisms such as sponges may vary among and within neighbouring reefs. In the present study, we examined small-scale variation of dictyoceratid sponges (class Demospongiae), commonly found on coral reefs, by surveying six neighbouring islands in central Torres Strait. Each island had four study sites, at least 1 km apart, with each site consisting of three shallow (4 to 6 m) and three deep (10 to 15 m) 20 m2 transects. For each transect, we recorded the number of each species and measured the size of the more common dictyoceratid sponges. Seven species of dictyoceratid were recorded in central Torres Strait, with only three species, Coscinoderma sp., Dysidea herbacea and Hyrtios erecta, common to all six islands. Abundance patterns generally varied greatly among islands or sites within islands, perhaps resulting from a combination of physical, biological and stochastic factors. More dictyoceratids were found in deeper water; however, abundance across depth for some species varied among islands or sites. Size-frequency distribution patterns also varied greatly among islands and dictyoceratid species, indicating that factors that may promote growth for one species may not necessarily promote growth for a related species. This study shows that patterns of abundance and size of dictyoceratids can vary greatly over small spatial scales, and that patterns are species-specific.

scholarly journals Colonization of macroalgal deposits by estuarine nematodes through air and potential for rafting inside algal structures

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0246723
Author(s):  
Bartelijntje Buys ◽  
Sofie Derycke ◽  
Nele De Meester ◽  
Tom Moens
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Distribution Patterns ◽  
Bedload Transport ◽  
Life History Trait ◽  
Small Scale ◽  
Marine Nematodes ◽  
Dispersal Capacity ◽  
Habitat Patches ◽  
Set Up

Dispersal is an important life-history trait. In marine meiofauna, and particularly in nematodes, dispersal is generally considered to be mainly passive, i.e. through transport with water currents and bedload transport. Because nematodes have no larval dispersal stage and have a poor swimming ability, their per capita dispersal capacity is expected to be limited. Nevertheless, many marine nematode genera and even species have near-cosmopolitan distributions, and at much smaller spatial scales, can rapidly colonise new habitat patches. Here we demonstrate that certain marine nematodes, like the morphospecies Litoditis marina, can live inside macroalgal structures such as receptacula and–to a lesser extent–floating bladders, which may allow them to raft over large distances with drifting macroalgae. We also demonstrate for the first time that these nematodes can colonize new habitat patches, such as newly deposited macroalgal wrack in the intertidal, not only through seawater but also through air. Our experimental set-up demonstrates that this aerial transport is probably the result of hitchhiking on vectors such as insects, which visit, and move between, the patches of deposited algae. Transport by wind, which has been observed for terrestrial nematodes and freshwater zooplankton, could not be demonstrated. These results can be important for our understanding of both large-scale geographic distribution patterns and of the small-scale colonization dynamics of habitat patches by marine nematodes.

scholarly journals Management of invasive alien species in Spain: A bibliometric review

NeoBiota ◽  
2021 ◽  
Vol 70 ◽  
pp. 123-150
Author(s):  
Rafael Muñoz-Mas ◽  
Martina Carrete ◽  
Pilar Castro-Díez ◽  
Miguel Delibes-Mateos ◽  
Josep A. Jaques ◽  
...  
Keyword(s):  
Alien Species ◽  
Invasive Alien Species ◽  
Spatial Scales ◽  
Grey Literature ◽  
Research Management ◽  
Giant Reed ◽  
Small Scale ◽  
Inland Waters ◽  
Network Analyses ◽  
Species Specific

Scientific and grey literature on invasive alien species (IAS) is conditioned by social, economic and political priorities, editorial preferences and species and ecosystem characteristics. This leads to knowledge gaps and mismatches between scientific research interests and management needs. We reviewed the literature on IAS management in Spain found in Scopus, Web of Science, Google Scholar and Dialnet to identify key deficiencies and priority research areas. The collected literature was classified, employing features describing formal aspects and content. We used bibliometric and keyword co-occurrence network analyses to assess the relationship between features and reveal the existence of additional topics. Most of the compiled documents (n = 388) were focused on terrestrial ecosystems and inland waters, whereas marine and urban ecosystems were under-represented. The literature was largely generic and not species-specific, focusing on raising awareness and proposing changes on current regulation as prominent approaches to prevent further introductions. The compiled authors exhibited many clear publishing preferences (e.g. language or document type), but less regarding target taxa. In addition, there was a strong association between species and the different features considered, especially between the methodological approach (e.g. review, field experiment) and the primary emphasis of study (i.e. basic/theoretical, applied or interdisciplinary). This indicates that research on IAS has had a strong species-specific focus. References about terrestrial species focused mainly on vascular plants, whereas references about inland waters were mostly on fishes and the giant reed (Arundo donax), which has been managed with partial success. Animal culling and plant removal were the most frequent eradication and small-scale control treatments, whereas the documents addressing wider spatial scales were largely theoretical. Consequently, the success of described treatments was largely uncertain. Spanish invasion science research has been occasionally innovative, incorporating novel technologies (e.g. species distribution modelling) and engaging society with citizen-science approaches. However, the ratio between basic/theoretical and applied studies indicates that more applied research/management is needed, especially in inland waters and marine ecosystems. We call for increasing effort in the effective dissemination of experience in IAS management to enhance current practical knowledge, including that of schemes undertaken by public agencies.

scholarly journals A continental measure of urbanness predicts avian response to local urbanization

2019 ◽  
Author(s):  
Corey Thomas Callaghan ◽  
Richard E. Major ◽  
William K. Cornwell ◽  
Ailstair G. B. Poore ◽  
John Wilshire ◽  
...  
Keyword(s):  
Citizen Science ◽  
Spatial Scales ◽  
Environmental Parameters ◽  
Local Scale ◽  
Systematic Sampling ◽  
Small Scale ◽  
Science Data ◽  
Continental Scale ◽  
Specific Variation ◽  
Species Specific

Understanding species-specific relationships with their environment is essential for ecology, biogeography, and conservation biology. Moreover, understanding how these relationships change with spatial scale is critical to mitigating potential threats to biodiversity. But methods which measure inter-specific variation in responses to environmental parameters, generalizable across multiple spatial scales, are lacking. We used broad-scale citizen science data, over a continental scale, integrated with remotely-sensed products, to produce a measure of response to urbanization for a given species at a continental-scale. We then compared these responses to modelled responses to urbanization at a local-scale, based on systematic sampling within a series of small cities. For 49 species which had sufficient data for modelling, we found a significant relationship (R2 = 0.51) between continental-scale urbanness and local-scale urbanness. Our results suggest that continental-scale responses are representative of small-scale responses to urbanization. We also found that relatively few citizen science observations (~250) are necessary for reliable estimates of continental-scale urban scores to predict local-scale response to urbanization. Our method of producing species-specific urban scores is robust and can be generalized to other taxa and other environmental variables with relative ease.

scholarly journals Annual and spatial variation in composition and activity of terrestrial mammals on two replicate plots in lowland forest of eastern Ecuador

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4241 ◽  
Author(s):  
John G. Blake ◽  
Bette A. Loiselle
Keyword(s):  
Spatial Scales ◽  
Distribution Patterns ◽  
Camera Traps ◽  
Small Scale ◽  
Lowland Forest ◽  
Terrestrial Mammals ◽  
Camera Location ◽  
Lowland Forests ◽  
A Site ◽  
Capture Rates

Terrestrial mammals are important components of lowland forests in Amazonia (as seed dispersal agents, herbivores, predators) but there are relatively few detailed studies from areas that have not been affected by human activities (e.g., hunting, logging). Yet, such information is needed to evaluate effects of humans elsewhere. We used camera traps to sample medium to large-sized terrestrial mammals at a site in lowland forests of eastern Ecuador, one of the most biologically rich areas in the world. We deployed cameras on two study plots in terra firme forest at Tiputini Biodiversity Station. Sixteen cameras were arranged 200 m apart in a 4 × 4 grid on each plot. Cameras were operated for  60 days in January–March, 2014–2017, for a total of 3,707 and 3,482 trap-days on the two plots (Harpia, Puma). A total of 28 species were recorded; 26 on Harpia and 25 on Puma. Number of species recorded each year was slightly greater on Harpia whereas overall capture rates (images/100 trap-days) were higher on Puma. Although most species were recorded on each plot, differences in capture rates meant that yearly samples on a given plot were more similar to each other than to samples on the other plot. Images of most species showed a clumped distribution pattern on each plot; Panthera onca was the only species that did not show a clumped distribution on either plot. Images at a given camera location showed no evidence of autocorrelation with numbers of images at nearby camera locations, suggesting that species were responding to small-scale differences in habitat conditions. A redundancy analysis showed that environmental features within 50 or 100 m of camera locations (e.g., elevation, variation in elevation, slope, distance to streams) accounted for significant amounts of variation in distribution patterns of species. Composition and relative importance based on capture rates were very similar to results from cameras located along trails at the same site; similarities decreased at increasing spatial scales based on comparisons with results from other sites in Ecuador and Peru.

Ecology and distribution of Dermatocarpon (Verrucariaceae, Ascomycota) in the catchment areas of two Bulgarian rivers

2018 ◽  
Vol 50 (6) ◽  
pp. 679-690 ◽  
Author(s):  
Veselin V. SHIVAROV ◽  
Cvetomir M. DENCHEV ◽  
Holger THÜS
Keyword(s):  
Colony Size ◽  
Sequence Data ◽  
Global Climate ◽  
Biological Effects ◽  
Distribution Patterns ◽  
Small Scale ◽  
Rock Surface ◽  
South East Europe ◽  
Catchment Areas ◽  
Study Sites

AbstractTemperature preferences and small-scale distribution patterns of four Dermatocarpon taxa in the catchment areas of two Bulgarian rivers were analyzed. Taxa with an overall alpine or arctic-alpine distribution were restricted to microhabitats with the lowest water and rock surface temperatures. A trend for increasing Dermatocarpon rivulorum thallus diameter and colony size (aggregates of thalli) with decreasing temperature was identified. Data on pH and conductivity of the water for the study sites are provided for all taxa. Dermatocarpon arnoldianum is reported for the first time from Bulgaria, confirmed by ITS sequence data, and its known range extends to South-East Europe. All previous records of D. rivulorum from Bulgaria were based on misidentified specimens of D. arnoldianum. Freshwater taxa of Dermatocarpon are proposed as a tool for monitoring the biological effects of temperature changes due to global climate change. Thallus and colony size are recommended as additional features for monitoring populations of threatened Dermatocarpon species.

Effects of Predation and Trophic Conditions on the Reproduction of Tylototriton verrucosus (Caudata: Salamandridae) in Darjeeling

2011 ◽  
Vol 4 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Ritwik Dasgupta
Keyword(s):  
Frequency Distribution ◽  
Primary Productivity ◽  
Egg Size ◽  
Zooplankton Abundance ◽  
Trophic Conditions ◽  
Size Frequency Distribution ◽  
Size Frequency ◽  
High Predation ◽  
Hatchling Size ◽  
Predation Rates

The facts that small hatchlings emerged from small eggs laid under high predation levels prevailing at the lower altitudes of distribution of this species in Darjeeling while larger hatchlings emerged from larger eggs laid under lower levels of predation at higher altitudes, show that predation is not selected for large egg and initial hatchling size in this salamandrid species. Metamorphic size was small under high predation rates because this species relied on crypsis for evading predators. Egg and hatchling size are related inversely to levels of primary productivity and zooplankton abundance in lentic habitats. Hatchling sizes are related positively to egg size and size frequency distribution of zooplankton. Small egg and small hatchling size have been selected for at the lower altitudes of distribution of this salamandrid in Darjeeling because predation rates increased in step with improvement in trophic conditions at the lower altitudes.

Präzisions-Forstwirtschaft – was ist das? | Precision forestry – what's that?

2007 ◽  
Vol 158 (8) ◽  
pp. 235-242 ◽  
Author(s):  
Hans Rudolf Heinimann
Keyword(s):  
Business Processes ◽  
Spatial Scales ◽  
Supply Chain Coordination ◽  
Sensor Technology ◽  
Small Scale ◽  
Soil Physics ◽  
Coordination Problem ◽  
Precision Engineering ◽  
Precision Forestry ◽  
And Control

The term «precision forestry» was first introduced and discussed at a conference in 2001. The aims of this paper are to explore the scientific roots of the precision concept, define «precision forestry», and sketch the challenges that the implementation of this new concept may present to practitioners, educators, and researchers. The term «precision» does not mean accuracy on a small scale, but instead refers to the concurrent coordination and control of processes at spatial scales between 1 m and 100 km. Precision strives for an automatic control of processes. Precision land use differs from precision engineering by the requirements of gathering,storing and managing spatio-temporal variability of site and vegetation parameters. Practitioners will be facing the challenge of designing holistic, standardized business processes that are valid for whole networks of firms,and that follow available standards (e.g., SCOR, WoodX). There is a need to educate and train forestry professionals in the areas of business process re-engineering, computer supported management of business transactions,methods of remote sensing, sensor technology and control theory. Researchers will face the challenge of integrating plant physiology, soil physics and production sciences and solving the supply chain coordination problem (SCCP).

SIZE FREQUENCY DISTRIBUTION BIASES IN HORSESHOE CRAB MOLT ASSEMBLAGES: IMPLICATIONS FOR THE FOSSIL RECORD

2016 ◽  
Author(s):  
Shelly J. Wernette ◽  
◽  
Scott Evans ◽  
Christine Hall ◽  
Mary L. Droser ◽  
...  
Keyword(s):  
Frequency Distribution ◽  
Fossil Record ◽  
Horseshoe Crab ◽  
Size Frequency Distribution ◽  
Size Frequency
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