scholarly journals Behavioural hypervolumes of spider communities predict community performance and disbandment

2016 ◽  
Vol 283 (1844) ◽  
pp. 20161409 ◽  
Author(s):  
Jonathan N. Pruitt ◽  
Daniel I. Bolnick ◽  
Andrew Sih ◽  
Nicholas DiRienzo ◽  
Noa Pinter-Wollman
Keyword(s):  
Species Composition ◽  
Trait Diversity ◽  
Spider Communities ◽  
Behavioural Trait ◽  
Community Performance ◽  
Web Building ◽  
Behavioural Diversity ◽  
Trait Space

Trait-based ecology argues that an understanding of the traits of interactors can enhance the predictability of ecological outcomes. We examine here whether the multidimensional behavioural-trait diversity of communities influences community performance and stability in situ . We created experimental communities of web-building spiders, each with an identical species composition. Communities contained one individual of each of five different species. Prior to establishing these communities in the field, we examined three behavioural traits for each individual spider. These behavioural measures allowed us to estimate community-wide behavioural diversity, as inferred by the multidimensional behavioural volume occupied by the entire community. Communities that occupied a larger region of behavioural-trait space (i.e. where spiders differed more from each other behaviourally) gained more mass and were less likely to disband. Thus, there is a community-wide benefit to multidimensional behavioural diversity in this system that might translate to other multispecies assemblages.

scholarly journals Photosynthetic parameters of a sedge-grass marsh as a big-leaf: effect of plant species composition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Markéta Mejdová ◽  
Jiří Dušek ◽  
Lenka Foltýnová ◽  
Lenka Macálková ◽  
Hana Čížková
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Photosynthetic Parameters ◽  
Acorus Calamus ◽  
Dominant Plant Species ◽  
Local Plant ◽  
Rate Of Photosynthesis ◽  
Carex Acuta ◽  
Leaf P

AbstractThe study estimates the parameters of the photosynthesis–irradiance relationship (PN/I) of a sedge-grass marsh (Czech Republic, Europe), represented as an active “green” surface—a hypothetical “big-leaf”. Photosynthetic parameters of the “big-leaf” are based on in situ measurements of the leaf PN/I curves of the dominant plant species. The non-rectangular hyperbola was selected as the best model for fitting the PN/I relationships. The plant species had different parameters of this relationship. The highest light-saturated rate of photosynthesis (Asat) was recorded for Glyceria maxima and Acorus calamus followed by Carex acuta and Phalaris arundinacea. The lowest Asat was recorded for Calamagrostis canescens. The parameters of the PN/I relationship were calculated also for different growth periods. The highest Asat was calculated for the spring period followed by the summer and autumn periods. The effect of the species composition of the local plant community on the photosynthetic parameters of the “big-leaf” was addressed by introducing both real (recorded) and hypothetical species compositions corresponding to “wet” and “dry” hydrological conditions. We can conclude that the species composition (or diversity) is essential for reaching a high Asat of the “big-leaf ”representing the sedge-grass marsh in different growth periods.

scholarly journals Hyperspectral Remote Sensing of Phytoplankton Species Composition Based on Transfer Learning

2019 ◽  
Vol 11 (17) ◽  
pp. 2001 ◽  
Author(s):  
Qing Zhu ◽  
Fang Shen ◽  
Pei Shang ◽  
Yanqun Pan ◽  
Mengyu Li
Keyword(s):  
Remote Sensing ◽  
Species Composition ◽  
Transfer Learning ◽  
Natural Waters ◽  
Hyperspectral Remote Sensing ◽  
Sensor Technology ◽  
Percentage Error ◽  
Phytoplankton Species ◽  
Phytoplankton Species Composition

Phytoplankton species composition research is key to understanding phytoplankton ecological and biogeochemical functions. Hyperspectral optical sensor technology allows us to obtain detailed information about phytoplankton species composition. In the present study, a transfer learning method to inverse phytoplankton species composition using in situ hyperspectral remote sensing reflectance and hyperspectral satellite imagery was presented. By transferring the general knowledge learned from the first few layers of a deep neural network (DNN) trained by a general simulation dataset, and updating the last few layers with an in situ dataset, the requirement for large numbers of in situ samples for training the DNN to predict phytoplankton species composition in natural waters was lowered. This method was established from in situ datasets and validated with datasets collected in different ocean regions in China with considerable accuracy (R2 = 0.88, mean absolute percentage error (MAPE) = 26.08%). Application of the method to Hyperspectral Imager for the Coastal Ocean (HICO) imagery showed that spatial distributions of dominant phytoplankton species and associated compositions could be derived. These results indicated the feasibility of species composition inversion from hyperspectral remote sensing, highlighting the advantages of transfer learning algorithms, which can bring broader application prospects for phytoplankton species composition and phytoplankton functional type research.

scholarly journals Variation in web-building spider communities among three tropical tree species in a young experimental plantation

2017 ◽  
Vol 45 (1) ◽  
pp. 139
Author(s):  
Luis Esquivel-Gómez ◽  
Luis Abdala-Roberts ◽  
Miguel Pinkus-Rendón ◽  
Víctor Parra-Tabla
Keyword(s):  
Tree Species ◽  
Tropical Tree ◽  
Tropical Tree Species ◽  
Spider Communities ◽  
Web Building

scholarly journals Primary production during nutrient-induced blooms at elevated CO<sub>2</sub> concentrations

2007 ◽  
Vol 4 (6) ◽  
pp. 4385-4410 ◽  
Author(s):  
J. K. Egge ◽  
T. F. Thingstad ◽  
A. Engel ◽  
R. G. J. Bellerby ◽  
U. Riebesell
Keyword(s):  
Species Composition ◽  
Primary Production ◽  
Experimental Period ◽  
Mineral Nutrient ◽  
Substantial Part ◽  
Phytoplankton Species ◽  
Net Community Production ◽  
Phytoplankton Species Composition ◽  
Alternative Hypotheses

Abstract. Mesocosms experiments (PeECE II and PeECE III) were carried out in 9 transparent mesocosms. Prior to the experimental period, the seawater carbonate system was manipulated to achieve three different levels of CO2. At the onset of the experimental period, nutrients were added to all mesocosms in order to initiate phytoplankton blooms. Rates of primary production were measured by in-situ incubations using 14C-incorporation and oxygen production/consumption. Particulate primary production by 14C was also size fractionated and compared with phytoplankton species composition. Nutrient supply increased the primary production rates, and a net autotrophic phase with 14C-fixation rates up to 4 times higher than initial was observed midway through the 24 days experiment before net community production returned to near-zero and 14C-fixation rates relaxed back to lower than initial. We found a trend in the 14C-based measurements towards higher cumulative primary production at higher pCO2, consistent with recently published results for DIC removal (Riebesell et al., 2007). There where found differences to the size fractionated primary production response to CO2 treatments. The plankton composition changes throughout the bloom, however, resulted in no significant response until the final phase of the experiment where phytoplankton growth became nutrient limited, and phytoplankton community changed from diatom to flagellate dominance. This opens for the two alternative hypotheses that such an effect is associated with mineral nutrient limited growth, and/or with phytoplankton species composition. The lack of a clear net heterotrophic phase in the last part of the experiment supports the idea that a substantial part of production in the upper layer was not degraded locally, but either accumulated there or was exported vertically.

A comparison of the species composition of spider communities over sixty years in th vicinity of Krotoszyn

1999 ◽  
Vol 42 (1-6) ◽  
pp. 29-40 ◽  
Author(s):  
Paweł Szymkowiak ◽  
Marek Woźny ◽  
Monika Błażejczyk
Keyword(s):  
Species Composition ◽  
Spider Communities

SPIDERS (ARANEAE) IN CORN FIELDS IN QUEBEC

1988 ◽  
Vol 120 (2) ◽  
pp. 97-100 ◽  
Author(s):  
Louis Provencher ◽  
Daniel Coderre ◽  
Charles D. Dondale
Keyword(s):  
Species Composition ◽  
Vertical Distribution ◽  
Dominant Species ◽  
Spider Species ◽  
Vertical Distributions ◽  
Corn Fields ◽  
Corn Plants ◽  
Web Building ◽  
The Vertical Distribution

AbstractThe purpose of this study was to determine spider species composition and their temporal and vertical distributions in corn in southern Quebec. We sampled 30 corn plants weekly for 12 weeks from 9 July to 23 September in 1985. We found nine families, 14 genera, and 12 identifiable species. Web-building spiders were more abundant than hunting spiders. The dominant species was Tetragnatha laboriosa Hentz (Tetragnathidae). Web-builders were generally found under the ear of the plant, whereas the vertical distribution of hunting spiders was more even.

scholarly journals Deficits in functional trait diversity following recovery on coral reefs

2020 ◽  
Vol 287 (1918) ◽  
pp. 20192628 ◽  
Author(s):  
Mike McWilliam ◽  
Morgan S. Pratchett ◽  
Mia O. Hoogenboom ◽  
Terry P. Hughes
Keyword(s):  
Coral Cover ◽  
Functional Trait ◽  
Important Species ◽  
Response Diversity ◽  
Disturbance Regimes ◽  
Functional Attributes ◽  
Trait Diversity ◽  
Location Response ◽  
Functional Trait Diversity ◽  
Trait Space

The disturbance regimes of ecosystems are changing, and prospects for continued recovery remain unclear. New assemblages with altered species composition may be deficient in key functional traits. Alternatively, important traits may be sustained by species that replace those in decline (response diversity). Here, we quantify the recovery and response diversity of coral assemblages using case studies of disturbance in three locations. Despite return trajectories of coral cover, the original assemblages with diverse functional attributes failed to recover at each location. Response diversity and the reassembly of trait space was limited, and varied according to biogeographic differences in the attributes of dominant, rapidly recovering species. The deficits in recovering assemblages identified here suggest that the return of coral cover cannot assure the reassembly of reef trait diversity, and that shortening intervals between disturbances can limit recovery among functionally important species.

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