scholarly journals First Descriptions of Aquatic Arthropods in an Unpolluted Native Forest Relict (Rucamanque, 38° S, Araucaria Region, Chile)

Zoodiversity ◽  
2021 ◽  
Vol 55 (3) ◽  
pp. 195-200
Author(s):  
P. De los Rios-Escalante ◽  
A. Alejandro Espinosa ◽  
P. Nunez

The Araucania region (38° S, Chile) originally had native perennial forest in middle valleys regions, that was gradually replaced by towns and agricultural zones during the last century, nevertheless there is some relicts of these native forests that are preserved, one of these relicts is Rucamanque, a protected area in the surrounding of Temuco town. The aim of the present study was a first aquatic Arthropoda description in a stream of this protected area using species co-occurrence and niche overlap null models. The results of species co-occurrence null model revealed that species associations are random, whereas the results of niche sharing revealed that species reported have different ecological niches, and in consequence there is not interspecifi c competence. The exposed results revealed the presence of aquatic fauna representative for unpolluted streams; similar descriptions were found for other similar inland water ecosystems in Argentinean and Chilean Patagonia.

2014 ◽  
Vol 74 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Patricio De los Ríos-Escalante ◽  
Esteban Quinán ◽  
Patricio Acevedo

The Chilean Patagonia has numerous kinds of inland water ecosystems such as lakes, ponds, wetlands and rivers that have been poorly studied due to access difficulties. This study was carried out in Aysen region, in southern Chile, and it included different kinds of water bodies such as rivers, streams, ponds, lagoons and lakes distributed along an altitudinal gradient at 46° S. It was found a low species number, essentially cladocerans, copepods and amphipods. A null model was applied in order to determine the existence of regulator factors of species associations, and the results revealed that they are not random. The patterns would be influenced by geographical and limnological characteristics of the studied sites. Our results would agree with regional studies on habitat heterogeneity such as in Torres del Paine National Park and other zones in Tierra del Fuego island.


Crustaceana ◽  
2014 ◽  
Vol 87 (5) ◽  
pp. 540-550 ◽  
Author(s):  
Patricio De los Ríos-Escalante ◽  
Andrés Mansilla

The distribution of crustaceans of inland waters in southern Patagonia is characterized by the presence of sub-Antarctic and southern South American species. The aims of the present study were to study the geographical distribution of the calanoid copepod Boeckella brevicaudata (Brady, 1875) and the community structure of the zooplankton assemblages in which this species occurs. This last purpose was approached by applying null-models analyses based on species co-occurrence and niche-sharing. The species itself inhabits sub-Antarctic islands as well as southern South America. The results of the co-occurrence null model analysis revealed that the communities with this species have no regulating factors, whereas the niche overlap null model analysis revealed that these species share the same ecological niche. We thus found low abundances for all species, with specifically low B. brevicaudata abundance, at low mineral contents of the water. The results obtained were similar among sites in southern Argentinean and southern Chilean Patagonia, and on sub-Antarctic islands of which data were available.


2020 ◽  
Vol 110 ◽  
Author(s):  
Patricio De los Ríos-Escalante ◽  
Carlos Esse ◽  
Rodrigo Santander-Massa ◽  
Pablo Saavedra ◽  
Francisco Encina-Montoya

ABSTRACT The benthic fauna in northern Patagonian streams is characterized by presence of water quality indicator species. The aim of the present study was characterized the benthic communities in streams associated to sites with presence of Nothofagus forests and with human intervention without Nothofagus forests using null models in ecology, unified neutral theory of biodiversity (UNTB) and unweighted pair group method with arithmetic mean (UPGMA). The results of species co-occurrence null model revealed that species associations are random, whereas the results of niche overlap null models revealed the presence of niche overlap. The UNTB results revealed low species number. The results of UPGMA revealed that species composition is specific for each site existing marked differences. The exposed results agree with results observed for central and northern Patagonian Chilean rivers, where the species composition is variable in according to surrounding basin properties and seasonal conditions.


Crustaceana ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 1219-1230
Author(s):  
Patricio De los Ríos ◽  
Eriko Carreño

Abstract To date, he fairy shrimps (Anostraca) of Chilean inland waters have been poorly described. Those that were described mainly belong to the genus Branchinecta, and the reports are primarily restricted to shallow seasonal pools at the northern and southern extremes of Chile. The aim of the present study was to give a first description of Branchinecta rocaensis, reported from ephemeral coastal pools in the Puaucho dunes, situated in the Araucania region. The results of null model analysis revealed first, that species associations are random and that there is niche overlap, while according to the principal component analysis, B. rocaensis was present at sites with low conductivity, low total dissolved solids and low temperature values, but with a high abundance of ostracods. The results obtained would agree with similar observations for Branchinecta habitats in southern Chilean Patagonia.


Crustaceana ◽  
2014 ◽  
Vol 87 (11-12) ◽  
pp. 1377-1385
Author(s):  
Patricio De los Ríos-Escalante ◽  
Andrés Muñoz-Pedreros ◽  
Patricia Möller

The inland water bodies of northern Chilean Patagonia (38-41°S) have many lakes, wetlands and ponds with different littoral and zooplanktonic crustacean assemblages. This study presents field observations of species associations sampled from shallow wetlands located in the urban zones of Valdivia (39°S) and Puerto Montt (41°S). A species presence-absence matrix was created for calculating the Jaccard Index of community similarity and for testing null models of species associations, with the aim of determining whether species associations are random or not. The results of the Jaccard Index calculations indicated the existence of non-defined groups. The results of the null model analysis denoted the presence of regulating factors for Valdivia wetlands, whereas for Puerto Montt wetlands no such factors could be demonstrated. The outcomes of both the Jaccard Index and the significant null model analysis agree with previous ecological descriptions of changes in trophic status as a consequence of changes in the surrounding basin as a determinant of species associations. The ecology of these communities is also discussed.


2007 ◽  
Vol 50 (6) ◽  
pp. 1051-1060 ◽  
Author(s):  
Avacir Casanova Andrello ◽  
Carlos Roberto Appoloni ◽  
Virgílio Franco do Nascimento Filho

The aim of this work was to assess the soil erosion process in native forest by the 137Cs methodology. The mass balance model was applied to assess the rates of soil loss in three native forests around of Londrina city, Paraná, Brazil. 137Cs distribution depth was of exponential type for the three forests and 137Cs inventory was 241 Bq m-2 for Mata 1, 338 Bq m-2 for Mata 2 and 325 Bq m-2 for Mata UEL. The soil loss value calculated for three native forests was: 6,684 kg ha-1 yr-1 for Mata 1, 1,788 kg ha-1 yr-1 for Mata 2 and 4,524 kg ha-1 yr-1 for Mata UEL.


2021 ◽  
Vol 9 (12) ◽  
pp. 1353
Author(s):  
Guillermo Figueroa-Muñoz ◽  
Carlos Molinet ◽  
Manuel Díaz ◽  
Patricio De los Ríos-Escalante

The southern king crab, Lithodes santolla, is an important fishery resource in the inner seas of Chilean Patagonia. The fishing gear used to catch southern king crab (bait trap) and its operation at different depths over several months provide the opportunity to gather information about relative abundance. The aim of the present study was to analyze the information collected from the catches of southern king crab and its associated fauna in the Magdalena Fjord to study the biodiversity and ecology of scavenging decapod crustaceans. Specifically, the study aimed to determine the bathymetric patterns of abundance by species, to model the abundance by season (winter and spring) and to determine the structuring pattern of scavenging decapods assemblage. Samples were collected between June and November 2019 by deploying traps in four bathymetric strata: 1 = 0–50 m; 2 = 51–100 m; 3 =101–150 m; 4 = 151–200 m. We registered a total of 673 decapod specimens associated with the southern king crab fishery, representing five species: Lithodes santolla (n = 96), Libidoclaea smithii (n = 10), Metacarcinus edwardsii (n = 58), Munida gregaria (n = 507) and Peltarion spinulosum (n = 2). The abundance of decapod species varied by month and bathymetric strata. We found bathymetric patterns for L. santolla abundance, M. gregaria, M. edwardsii, and total species abundance. The most informative model to explain scavenging decapod abundance by generalized linear model (GLM) included species and season. The null model of species co-occurrence analysis revealed that all species associations during the sampled months were random. Our study is the first that provides evidence about patterns of bathymetrical and temporal variation of scavenging decapod abundance and expands the body of knowledge regarding the biodiversity of scavenger decapods in the Magdalena Sound.


2020 ◽  
Vol 84 (2) ◽  
Author(s):  
Patricio De los Ríos-Escalante ◽  
Guillermo Figueroa-Muñoz ◽  
Marco A. Retamal ◽  
Rolando Vega-Aguayo ◽  
Carlos Esse

The intertidal crustaceans on the Chilean coast are characterized by high diversity and niche specialization. The present study applied a size overlap null model for intertidal decapod communities at four different sites on the Chilean coast. The results revealed that there is a size overlap for the four sites, though body size is significantly different for each location. This means that the reported species would share their ecological niches. The results agree with the first classic environmental descriptions for Chilean intertidal decapods at a local scale and support the observations for similar species on the southern Pacific and southern Atlantic coasts.


Mycorrhiza ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 749-759
Author(s):  
Zerihun Belay ◽  
Mesele Negash ◽  
Janne Kaseva ◽  
Mauritz Vestberg ◽  
Helena Kahiluoto

Abstract The rapid conversion of native forests to farmland in Ethiopia, the cradle of biodiversity, threatens the diversity of the arbuscular mycorrhizal fungi (AMF) pivotal to plant nutrition and carbon sequestration. This study aimed to investigate the impact of this land-use change on the AMF species composition and diversity in southern Ethiopia. Soil samples were collected from nine plots in each of three land-use types: native forest, agroforestry, and khat monocropping. The plots of the three land-use types were located adjacent to each other for each of the nine replicates. Three 10 × 10m subplots per plot were sampled. AMF spores were extracted from the soil samples, spore densities were determined, and species composition and diversity were evaluated through morphological analysis. Both spore density and species richness were statistically significantly higher in the native forest than in the agroforestry plots with no clear difference to khat, whereas the true diversity (exponential of Shannon–Wiener diversity index) did not differ among the three land-use types due to high evenness among the species in agroforestry. In total, 37 AMF morphotypes belonging to 12 genera in Glomeromycota were found, dominated by members of the genera Acaulospora and Glomus. The highest isolation frequency index (78%) was recorded for Acaulospora koskei from native forest. Consequently, the agroforestry system did not appear to aid in preserving the AMF species richness of native forests relative to perennial monocropping, such as khat cultivation. In contrast, the native forest areas can serve as in situ genetic reserves of mycorrhizal symbionts adapted to the local vegetative, edaphic, and microbial conditions.


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