Occurrence and fate of current-use pesticides in Chinese forest soils.

Pesticides play a crucial role in securing global food production to meet increasing demands. However, because of their pervasive use, they are now ubiquitous environmental pollutants that have adverse effects on both ecosystems and human health. In this study, the environmental occurrence and fate of 16 current-use pesticides (CUPs) were investigated in 93 forest soil samples obtained from 11 distinct mountains in China. The concentrations of the target pesticides ranged from 0.36 to 55 ng/g dry weight. Cypermethrin, dicofol, chlorpyrifos, chlorothalonil, and trifluralin were the most frequently detected CUPs. The CUP concentrations were generally higher in the O-horizon than in the A-horizon. Chlorpyrifos, chlorothalonil, and dicofol were detected in most deep layers in soil profiles from three mountains selected to represent distinct climate zones. No clear altitudinal trend in organic carbon-normalized concentrations of CUPs was observed in the O- or A-horizons within individual mountains. A negative correlation was noted between the CUP concentrations and the altitudes across all sampling sites. This indicated that proximity to emission sources was a key factor affecting the spatial distribution of CUPs in mountain forest soil on a national scale. The ecological risk assessment showed that dicofol and cypermethrin pose potential risks to earthworms. This study emphasizes the importance of source control when setting management strategies for CUPs.

Pre-pollination barriers between two sympatric Arisaema species in northern Shikoku Island, Japan.

PREMISE: The genus Arisaema (Araceae) has rapidly diversified in Japan, and multiple species often coexist in the field. Although Japanese Arisaema species hybridize from artificial crossing, hybrid individuals are rare in mixed populations; suggesting the presence of effective pre-pollination barriers. We examined the following reproductive barriers between A. sikokianum and A. tosaense: habitat, phenology, and pollinator isolations. METHODS: Habitat isolation was examined by interspecific comparisons of microhabitat conditions at a mixed site and of altitude at the sampling site of herbarium specimens. Phenological isolation was evaluated by comparing seasonal transition in apparent spathe condition and frequency of insect visitation. Pollinator isolation was examined by comparing floral visitor assemblages between the two Arisaema species. To avoid overestimation of pollinator isolation due to seasonal changes in insect assemblages, we also compared visitor assemblages between natural and late-flowering A. sikokianum, where the latter was experimentally introduced and blooming with a natural A. tosaense population. RESULTS: Microhabitat conditions and sampling elevations of herbarium specimens overlapped between the two Arisaema species. At the population level, A. sikokianum and A. tosaense flowered for 39 and 52 days, respectively, with 13 days overlap. Insect visitation in A. sikokianum decreased before the seasonal overlap. Floral visitor assemblages differed between the two Arisaema species, while the difference between natural and late-flowering A. sikokianum was less distinct. CONCLUSIONS: Phenological and pollinator isolation contribute to reproductive isolation between the two Arisaema species and should enable the two species to coexist in this area.

Mercury isotopic compositions of mosses, conifer needles, and surface soils: Implications for mercury distribution and sources in Shergyla Mountain, Tibetan Plateau.

Understanding the distribution and sources of mercury (Hg) in the Tibetan Plateau is of great value to study the long-range transport of Hg. Herein, the total Hg (THg) concentrations and the isotopic compositions of mosses, conifer needles, and surface soils collected from both slopes of the Shergyla Mountain of Tibetan Plateau were analyzed. The contents of THg in samples (except mosses on the eastern slope) were significantly positively correlated with altitude in both the western and eastern slopes, possibly caused by topographic factors. In contrast, Δ199Hg in samples was significantly negatively correlated with altitude. On the basis of Hg isotopic compositions, atmospheric Hg0 uptake was indicated as the primary accumulation pathway of Hg in mosses (Δ199Hg: -0.12 ±â€¯0.09‰, -0.26 - 0.00‰, 1 SD, n = 10) and conifer needles (Δ199Hg: -0.21 ±â€¯0.08‰, -0.36 - -0.11‰, 1 SD, n = 9). Moreover, the contributing fractions of atmospheric Hg0 to Hg in surface soils (Δ199Hg: -0.20 ±â€¯0.07‰, -0.31 - -0.06‰, 1 SD, n = 17) increased with altitude and accounted for an average of 87 ± 9% in atmospheric sources. Due to the special geographic positions and environmental conditions of the Tibetan Plateau, the results of this study were essential for further understanding the long-range transport and global cycling of Hg.

Geographic Variation in Skull Morphology of the Large Japanese Field Mice, Apodemus speciosus (Rodentia: Muridae) Revealed by Geometric Morphometric Analysis.

We analyzed geographic variation in skull morphology of the large Japanese field mouse (Apodemus speciosus) and determined changes in skull morphology that occurred during the evolutionary history of A. speciosus in relation to the estimated distribution range in the last glacial maximum (LGM). We analyzed 1,416 specimens from 78 localities using geometric morphometric techniques applied to the dorsal side of the cranium and mandible. While large variations within and among the populations in Honshu, Shikoku, and Kyushu were observed, geographic patterns were not observed. Hokkaido and peripheral island populations showed shared differentiation from the Honshu, Shikoku, and Kyushu populations with a larger skull and distinct mandible shape. In addition, these two groups also differed from each other in accumulated random shape variation. Common characteristics found in Hokkaido and peripheral island populations were considered to be the ancestral states, which were retained by geographic isolation from the main islands. Random variations in Hokkaido and the peripheral island populations were formed through stochastic processes in relation to their isolation. Characteristic morphologies widely found in the populations of Honshu, Shikoku, and Kyushu were considered to be derived states that expanded after separation from the peripheral islands. Complex geomorphology and a shift in distribution range related to climate change and altitudinal distribution are suggested to have formed the complex geographic variation in this species.

Altitudinal distribution and seasonal migration of asiatic black bear (Ursus thibetanus) in kaghan and Siran Valleys, Pakistan.

The Asiatic black bear (Ursus thibetanus) is considered one of the largest carnivores inhabiting different territories including coniferous and broad-leaved forests, extending from sea level to the elevation of 4300 m. The Kaghan and Siran Valleys in Pakistan's District Mansehra were the location of the current study. To evaluate the altitudinal distribution and seasonal movement of Asiatic black bears in the region, we used three approaches (sign distribution survey, questionnaire-based survey, and scat collecting). A total of 1858 bear signs were observed during the field survey, the highest number of signs was dig marks (1213) followed by plant uprooting. Dig marks (MER: 7.574) were observed repeatedly in each potential site of both valleys followed by plant uprooting (MER: 1.594). Similarly, the altitudinal distribution of black bears was determined through the frequency of signs concerning elevation (m). Elevation of the study area ranged from 1300 to 3500 m and the most abundant population was recorded at the elevation of 2501-3000 m followed by 2001-2500 m. About 52% of local communities encountered black bears during the summer season in the field followed by Spring (23%.8) and winter (15.3%). Manshi Reserver forest (24.5%) from Kaghan and Panjul Reserve forest (31.6) from Siran Valley are the potential summer migratory spots. Eleven scat samples were collected with a 0.103 encounter rate (ER). Most of the scats (about 70%) were observed within the maize crop field in the summer season at low elevation, while just 30% of the scat was observed in the winter season in the forest.

Contribution of Morphoanatomic Characters to the Taxonomy of the Genus LAELIA (Orchidaceae) in Mexico and Their Implication in Environmental Adaptation.

The Laeliinae Subtribe (Epidendroideae-Orchidaceae) is exclusively Neotropical, composed of 43 genera and 1466 species, presenting great floral and vegetative diversity. The genus Laelia has restricted geographic distribution, with species in Brazil and Mexico. However, in molecular studies, the Brazilian species have not been included despite remarkably similar floral structures in both Mexican and Brazilian groups of species. The main objective of the present study is to analyze vegetative structural characters of 12 species of Laelia in Mexico to find similarities to recognize them as a taxonomic group and their relationship with possible ecological adaptations. This work supports the proposal to recognize 12 species of Laelias from Mexico as a taxonomic group (except for the new species recognized as Laelia dawsonii J. Anderson), since a strong similarity was found, translated by 90% of structural characters shared by the Mexican Laelias, given the relationship between the structural characters and the altitudinal distribution in which the groups of Mexican Laelias species are found. We propose that Laelias of Mexico be recognized as a taxonomic group and their structural characteristics allow for better understanding of adaptation of species to their environment.

Different Distribution Patterns of Hoverflies (Diptera: Syrphidae) and Bees (Hymenoptera: Anthophila) Along Altitudinal Gradients in Dolomiti Bellunesi National Park (Italy).

Hoverflies (Diptera: Syrphidae) and bees (Hymenoptera: Anthophila) are two key taxa for plant pollination. In the present research, the altitudinal distribution of these taxa was studied along two gradients (elevation range: 780-2130 m) in the Dolomiti Bellunesi National Park (Northeastern Italy). Pan traps were used as a sampling device to collect both hoverflies and bees. Other than altitude, the effect of landscape complexity and plant diversity were considered as potential predictors of hoverfly and bee richness and abundance along the two gradients. A total of 68 species of hoverflies and 67 of bees were collected during one sampling year, confirming the efficacy of pan traps as a sampling device to study these taxa. Altitude was the main variable affecting both hoverfly and bee distribution. The two taxa show different distribution patterns: hoverflies have a unimodal distribution (richness and abundance) with peak at middle altitude (1500 m), while bees have a monotonic decline (richness and abundance) with increasing altitude. Both hoverfly and bee populations change with the increasing altitude, but the change in hoverflies is more pronounced than in bees. Species turnover dominates the ß-diversity both for hoverflies and bees; therefore, the hoverfly and bee communities at higher altitudes are not subsamples of species at lower altitude but are characterized by different species. This poses important conservation consequences. Some rare species, typical of an alpine habitat were recorded; the present research represents important baseline data to plan a monitoring scheme aimed at evaluating the effect of climate change on pollinators in these fragile habitats.

Occurrence and distribution of polyhalogenated carbazoles in eastern Tibetan Plateau soils along the slope of Mt. Qionglai.

Polyhalogenated carbazoles (PHCZs), are considered as potential persistent organic pollutants (POPs), which have been frequently detected in the environment. However, the altitudinal distribution characteristics and possible sources of PHCZs in high mountain soils are still unknown. The present study was the first to analyze PHCZs in soil samples collected along the eastern slope of Mt. Qionglai (MQ), the east edge of the Tibetan Plateau. The concentration of ΣPHCZs (based on dry weight) ranges from 14.4 to 107 ng/g (median value of 40.9), which was at high end of the range reported in soils and sediments to date in the literature. The composition profiles of PHCZs in the soils of MQ were dominated by 3,6-dichlorocarbazole (36-CCZ), 3-chlorocarbazole (3-CCZ), and 2-bromocarbazole (2-BCZ). The mean TOC-normalized concentrations of ΣPHCZs in soil samples from below-treeline (2092 ng/g TOC) were higher than those from alpine meadow (1124 ng/g TOC), probably due to the forest filter effect. The decreasing trend of the PHCZs TOC-normalized concentrations with altitude shows that accumulation of PHCZs from the alpine meadow samples was not affected by the mountain cold-trapping effect. Significantly positive correlations were observed between the concentrations of more than half of detected PHCZ congeners and TOC. In addition, PHCZs show the potential to represent a class of POPs with the frequent occurrence and wide distribution, as the abundance and environmental behavior of PHCZs are similar to some POPs in MQ.

Transient photoinhibition and photo-oxidative stress as an integral part of stress acclimation and plant development in a dioecious tree adapted to Mediterranean ecosystems.

Mastic trees (Pistacia lentiscus L.) are dioecious perennial plants that are highly adapted to Mediterranean climates but display a high sensitivity to winter periods. In order to understand how sex, leaf phenology and ecological context could condition sensitivity to winter and associated mechanisms to acclimate to these conditions, photoinhibition and photo-oxidative stress markers were examined in mastic trees (P. lentiscus) from a natural population growing in the Garraf Natural Park for a consecutive 12-month period (seasonal study), as well as in three populations naturally growing in the Montseny Natural Park, including the highest altitudes described for this species, during winter (altitudinal study). Results from these studies indicate that both the winter period and higher elevation influenced the degree of photoinhibition, but this was not conditioned by sex. In fact, winter photoinhibition occurred transiently even though it was accompanied by chlorophyll loss and malondialdehyde contents. Stress acclimation was achieved through biochemical adjustments in chloroplasts, characterized by anthocyanin shielding, increased de-epoxidation state of the xanthophyll cycle as well as tocopherol accumulation, and phenological adaptations, the latter allowing a complete resetting of the physiological performance of leaves. Moreover, although females showed higher lipid peroxidation than males during the coldest winter months, at the highest elevation and during flowering in spring, this oxidative stress was mild and transient with no negative consequences for the physiology of plants. It is concluded that evergreen mastic trees acclimate to winter conditions and higher elevations by activation of antioxidant defenses together with phenological adjustments, altogether playing a crucial role in plant survival. Sexual dimorphism in mastic trees appears as a relevant factor when considering sensitivity to photo-oxidative stress in winter and altitudinal conditions.

Distributional Patterns of Aquatic Empididae (Diptera) along an Elevational Diversity Gradient in a Low Mountain Range: An Example from Central Europe.

The two subfamilies Hemerodromiinae and Clinocerinae, also known as aquatic dance flies, are a group of small predatory insects occurring mainly in mountainous areas and the northern temperate. However, very little is known about distribution patterns for most of the species. Habitat preferences for 40 aquatic empidid species were analysed in the Pieniny Mts., Poland. Forty-six sampling sites from a major part of this relatively low mountain massif (400-770 m) were chosen, for which 17 micro and macrohabitat environmental variables were measured including both abiotic (altitude, stream mean width and depth, and shading) and biotic factors (13 dominant plant communities). Here we show that numerous studied aquatic Empididae were characterized by unique habitat preferences and were restricted to the foothills or the lower montane zone with only a few species characterized by wider elevational distribution. Chelifera pectinicauda, C. flavella, C. subangusta and Phyllodromia melanocephala (Hemerodromiinae), and Clinocera appendiculata, C. fontinalis, C. wesmaeli, Dolichocephala guttata, D. oblongoguttata, Kowarzia plectrum, Wiedemannia jazdzewskii, and W. thienemanni (Clinocerinae) were clearly associated with the highest altitudes and shaded areas while W. bistigma, W. lamellata, W. phantasma, and W. tricuspidata (Clinocerinae) were clearly associated with the lower elevated, wider stream valleys overgrown by willow brakes. Species richness and diversity decreased along elevational gradient with the hump-shaped diversity pattern noted for the subfamily Clinocerinae. The altitude, size of river/stream as well as the type of plant community were found as the most important factors in the distribution of the studied aquatic empidid species. The present study is the first one focused on elevational diversity gradient and habitat preferences of Hemerodromiinae and Clinocerinae of central Europe, and one of only a few in the world.

Leptoceroidea (Insecta: Trichoptera: Integripalpia) from Serra do Caparaó, Southeast Brazil, including a new species of Atanatolica Mosely (Leptoceridae).

Serra do Caparaó is an impressive mountain range between the states of Minas Gerais and Espírito Santo, Southeast Brazil, inserted within the Atlantic Forest biome, and has a mosaic vegetation composed mainly by Dense Ombrophilous Forest and rupicolous vegetation of high-altitude grasslands. This study contributes to increasing the knowledge on the Leptoceroidea fauna of the Serra do Caparaó. Herein, we describe and illustrate a new species of Leptoceridae, Atanatolica bandeira sp. nov. and provide additional data on the richness and distribution of Leptoceroidea from Parque Nacional do Caparaó and surrounding areas. The distribution of some species is expanded. Fourteen and four species are recorded for the first time from Espírito Santo and Minas Gerais states, respectively.

Coprophagous Hydrophilid Beetles (Coleoptera, Hydrophilidae, Sphaeridiinae) Distribution in the Polish Carpathians.

Research on coprophagous beetles of the Hydrophilidae family in the Polish Carpathians was conducted from 2011 to 2013. The beetles were caught using baited traps. The research sites were selected to take into account both the horizontal diversity of habitat conditions and the vertical diversity associated with elevation above sea level. During the study, 9589 coprophagous hydrophilid individuals were collected, representing 17 species and five genera. Two species that were new to Poland were found: Cercyon tatricus and Pachysternum capense. The vertical ranges of the individual species of coprophagous hydrophilid beetles within the Polish Carpathians were determined as well as the elevations above sea level, with the highest and lowest species richness of this group of insects. The capture of Pachysternum capense in the Tatra Mountains may indicate the existence of an unrecognized path of migration of small insects from Southern to Northern Europe. The route and mechanisms of their migration are discussed.

When a river is affected by a reservoir: Trophic interactions and flexibility in feeding strategies of alpine bullhead (Cottus poecilopus) and European bullhead (Cottus gobio).

The alpine bullhead and European bullhead are benthic fish species protected by law in several European countries. One of the problems of European rivers is the ever-increasing number of reservoirs, which has adverse impacts on aquatic ecosystems. Feeding ecology of both species evaluated separately has been a subject of several studies, however, none of the studies paid attention to feeding interactions between them. Thus, the aims of the study were to evaluate trophic interactions of the two bullhead species and to assess their ability to cope with environmental disturbances caused by a reservoir. The study area consisted of three sites on the river Cierny Váh (Slovakia) that differed from each other by the intensity of pressures posed by the reservoir. The two species were found to coexist at two sites below the reservoir, because the reservoir affected their distribution along the river. For alpine bullhead, chironomid, hydropsychid and baetid larvae were the most important prey items, whereas the diet spectrum of European bullhead contained hydropsychid, chironomid larvae and detritus. Differences in diet composition were found among sampling sites. Temporal variations in the diet composition demonstrated that alpine bullhead is a more flexible feeder than European bullhead. Being predominantly food generalists, both species were able to shift their feeding strategies towards specialization when exposed to environmental disturbances at the most affected site. The reservoir increased the diet overlap between the two species, and thus changed their trophic interactions. Both alpine bullhead and European bullhead managed to cope with environmental disturbances caused by the reservoir, however, in lower population densities. Moreover, the reduced diversity of resources increased the potential for trophic competition between them.

Nomenclatural changes in the higher classification of the family Tettigometridae (Hemiptera: Fulgoroidea) with description of a new tribe and new species and a review of the Iranian tettigometrid fauna.

The first part of this paper provides a historical review of the classification of the family Tettigometridae, including the description of a new tribe, Plesiometrini trib. nov. to accommodate three Afrotropical genera of the subfamily Tettigometrinae. The name Nototettigometra Muir 1924, is proposed to replace Hilda Kirkaldy 1900, homonym of Hilda Hörnes Auinger 1884, and corresponding new combinations are given, including Nototettigometrinae nom. subst. to replace Hildinae Fennah 1952. An identification key to suprageneric taxa of Tettigometridae including both male and female characters is provided. In the second part, 18 tettigometrid species are recorded from Iran. A new species, Tettigometra (Tettigometra) parihana sp. nov. is described. Tettigometra (Metroplaca) longicornis and Tettigometra (Tettigometra) impressifrons are reported as new records for the Iranian fauna. An identification key and distribution maps are provided for the Iran fauna.

Catalogue of Indian Notodontidae Stephens, 1829 (Lepidoptera: Noctuoidea).

The present communication consists of the first ever catalogue of Indian Notodontidae Stephens, 1829 comprising systematic accounts of 242 species (including nominotypical subspecies) and 10 subspecies under 116 genera of 10 subfamilies with four new records to India viz. Phalera (Phalera) birmicola Bryk, 1949, Spatalina desiccata stolida Schintlmeister, 2007, Hiradonta hannemanni Schintlmeister, 1989 and Kamalia tattakana (Matsumura, 1927). The account was prepared by compiling findings from both literature survey and field sampling carried out at various Protected Areas in the Indian Himalayas and Chhattisgarh state in the Deccan Peninsular region of India. Zoogeographic analysis of Indian Notodontidae reveals a majority of the assemblage showing Oriental (58.27%) and Palaearctic (40.49%) affinities with maximum species of Sundanian (80.00%), followed by Himalayan (77.65%) origins. In India, the majority of the species are distributed in the Himalayan (35.33%) and North-East (39.40%) biogeographic zones, reflecting maximum endemicity. Extensive surveys in the less explored southern part of the country are expected to enrich the inventory of Indian Notodontidae. The distribution map and detailed illustrations of the four new records are provided.

Altitudinal characteristics of atmospheric deposition of aerosols in mountainous regions: Lessons from the Fukushima Daiichi Nuclear Power Station accident.

To understand the formation process of radiologically contaminated areas in eastern Japan caused by the Fukushima Daiichi Nuclear Power Station (FDNPS) accident, the deposition mechanisms over complex topography are the key factors to be investigated. To characterize the atmospheric deposition processes of radionuclides over complex mountainous topography, we investigated the altitudinal distributions of the radiocesium deposited during the accident. In five selected areas, altitudinal characteristics of the air dose rates observed using airborne surveys were analyzed. To examine the deposition mechanisms, we supplementarily used vertical profiles of radiocesium deposition in each area calculated in the latest atmospheric dispersion model. In southern Iwate, the vertical profile of the observed air dose rate was uniform regardless of altitude. In western Tochigi, the areas with the highest levels of contamination were characteristically distributed in the middle of the mountains, while in southern Fukushima, the areas with the highest contamination levels were enhanced near the summits of mountains. In central Fukushima, high air dose rates were limited to the bottoms of basin-like valley. In the region northwest of FDNPS, the air dose rate was the highest at the bottom of valley topography and decreased gradually with altitude. The simulation results showed that calculated wet deposition and observed vertical profiles of total deposition were similar in areas of southern Iwate and northwest of FDNPS qualitatively, suggesting that the dominant deposition mechanism was wet deposition. In contrast, the atmospheric dispersion model failed to reproduce either the timing of precipitation events or vertical profiles of radiocesium deposition in three other areas. Although it was difficult to elucidate the deposition mechanisms in these areas due to uncertainties of the present model results, potential mechanisms such as cloud water deposition were still proposed based on circumstantial evidences of limited meteorological data during the early stage of the accident.

Macrozoobenthos in an altitudinal gradient in North Patagonian Cautín River (Araucanía Region, Chile) / Macrozoobentos em gradiente altitudinal no norte da Patagônia, Rio Cautín (38° S, região da Araucanía, Chile)

The Cautín River is closely related with the economic development of Temuco city, (38°S; Chile). Existing knowledge of the Cautín River is limited to information about its biological characteristics as a reference for the evaluation and assessment of water quality. The object of this study was to develop taxonomic characterisation of the benthic macroinvertebrates along the main course of the Cautín River, and to study the community structure using correlation analysis between community parameters. To carry out this research, the macroinvertebrate community was studied in 10 sampling sites distributed along the main course of the river. The samples were taken in summer (1997 and 2000), when optimal hydrological conditions existed. Analysis of the samples showed that the benthic fauna was composed of 56 taxa, the dominant group being insects with 48 taxa. Three main sectors were recognised in the course of the Cautín River: high, middle and low. Each sector has restricted-distribution species, while other species are widely distributed along the river. These distribution patterns seem to be influenced by dissolved oxygen concentration, temperature, altitudinal distribution and anthropo-cultural activity, present at every sampling site. Finally, this research provides a first approach to the biology of the Cautín River. Further studies could be planned on the basis of this knowledge to investigate water quality indicators based on macroinvertebrate communities.

O rio Cautín está intimamente relacionado ao desenvolvimento econômico da cidade de Temuco (38°S; Chile). Quanto ao conhecimento total do rio Cautín, existem informações limitadas sobre as características biológicas que podem servir de referência para a avaliação da qualidade da água. Este estudo tem o objetivo de caracterizar os macroinvertebrados bentônicos taxonomicamente ao longo do curso principal do rio Cautín e estudar a estrutura da comunidade usando análise de correlação entre os parâmetros dela. Para realizar esta pesquisa, a comunidade de macroinvertebrados foi estudada em dez locais de estudo distribuídos ao longo do rio principal. As amostras foram coletadas no verão (1997 e 2000), em razão das condições hidrológicas ideais. A análise das amostras mostrou que a fauna bentônica é composta de 56 táxons, sendo o grupo dominante o de insetos com 48 táxons. Na distribuição do principal no curso do rio, três setores são reconhecidos: alto, médio e baixo no rio Cautín. Cada setor possui espécies de distribuição restrita e outro com ampla distribuição ao longo do rio. Esses padrões de distribuição parecem influenciar a concentração de oxigênio dissolvido, a temperatura, a distribuição altitudinal e a atividade antropocultural desenvolvida em todos os locais de amostragem. Finalmente, esta pesquisa fornece uma primeira abordagem biológica do rio Cautín e, de acordo com esses conhecimentos, um estudo posterior pode ser planejado em relação aos indicadores de qualidade da água e com base nas comunidades de macroinvertebrados.

Macrozoobenthos in an altitudinal gradient in North Patagonian Cautín River (Araucanía Region, Chile)

Abstract The Cautín River is closely related with the economic development of Temuco city, (38°S; Chile). Existing knowledge of the Cautín River is limited to information about its biological characteristics as a reference for the evaluation and assessment of water quality. The object of this study was to develop taxonomic characterisation of the benthic macroinvertebrates along the main course of the Cautín River, and to study the community structure using correlation analysis between community parameters. To carry out this research, the macroinvertebrate community was studied in 10 sampling sites distributed along the main course of the river. The samples were taken in summer (1997 and 2000), when optimal hydrological conditions existed. Analysis of the samples showed that the benthic fauna was composed of 56 taxa, the dominant group being insects with 48 taxa. Three main sectors were recognised in the course of the Cautín River: high, middle and low. Each sector has restricted-distribution species, while other species are widely distributed along the river. These distribution patterns seem to be influenced by dissolved oxygen concentration, temperature, altitudinal distribution and anthropo-cultural activity, present at every sampling site. Finally, this research provides a first approach to the biology of the Cautín River. Further studies could be planned on the basis of this knowledge to investigate water quality indicators based on macroinvertebrate communities.

Resumo O rio Cautín está intimamente relacionado ao desenvolvimento econômico da cidade de Temuco (38°S; Chile). Quanto ao conhecimento total do rio Cautín, existem informações limitadas sobre as características biológicas que podem servir de referência para a avaliação da qualidade da água. Este estudo tem o objetivo de caracterizar os macroinvertebrados bentônicos taxonomicamente ao longo do curso principal do rio Cautín e estudar a estrutura da comunidade usando análise de correlação entre os parâmetros dela. Para realizar esta pesquisa, a comunidade de macroinvertebrados foi estudada em dez locais de estudo distribuídos ao longo do rio principal. As amostras foram coletadas no verão (1997 e 2000), em razão das condições hidrológicas ideais. A análise das amostras mostrou que a fauna bentônica é composta de 56 táxons, sendo o grupo dominante o de insetos com 48 táxons. Na distribuição do principal no curso do rio, três setores são reconhecidos: alto, médio e baixo no rio Cautín. Cada setor possui espécies de distribuição restrita e outro com ampla distribuição ao longo do rio. Esses padrões de distribuição parecem influenciar a concentração de oxigênio dissolvido, a temperatura, a distribuição altitudinal e a atividade antropocultural desenvolvida em todos os locais de amostragem. Finalmente, esta pesquisa fornece uma primeira abordagem biológica do rio Cautín e, de acordo com esses conhecimentos, um estudo posterior pode ser planejado em relação aos indicadores de qualidade da água e com base nas comunidades de macroinvertebrados.

Macrozoobenthos in an altitudinal gradient in North Patagonian Cautín River (Araucanía Region, Chile) / Macrozoobentos em gradiente altitudinal no norte da Patagônia, Rio Cautín (38° S, região da Araucanía, Chile)

The Cautín River is closely related with the economic development of Temuco city, (38°S; Chile). Existing knowledge of the Cautín River is limited to information about its biological characteristics as a reference for the evaluation and assessment of water quality. The object of this study was to develop taxonomic characterisation of the benthic macroinvertebrates along the main course of the Cautín River, and to study the community structure using correlation analysis between community parameters. To carry out this research, the macroinvertebrate community was studied in 10 sampling sites distributed along the main course of the river. The samples were taken in summer (1997 and 2000), when optimal hydrological conditions existed. Analysis of the samples showed that the benthic fauna was composed of 56 taxa, the dominant group being insects with 48 taxa. Three main sectors were recognized in the course of the Cautín River: high, middle and low. Each sector has restricted-distribution species, while other species are widely distributed along the river. These distribution patterns seem to be influenced by dissolved oxygen concentration, temperature, altitudinal distribution and anthropo-cultural activity, present at every sampling site. Finally, this research provides a first approach to the biology of the Cautín River. Further studies could be planned on the basis of this knowledge to investigate water quality indicators based on macroinvertebrate communities.

O rio Cautín está intimamente relacionado ao desenvolvimento econômico da cidade de Temuco (38°S; Chile). Quanto ao conhecimento total do rio Cautín, existem informações limitadas sobre as características biológicas que podem servir de referência para a avaliação da qualidade da água. Este estudo tem o objetivo de caracterizar os macroinvertebrados bentônicos taxonomicamente ao longo do curso principal do rio Cautín e estudar a estrutura da comunidade usando análise de correlação entre os parâmetros dela. Para realizar esta pesquisa, a comunidade de macroinvertebrados foi estudada em dez locais de estudo distribuídos ao longo do rio principal. As amostras foram coletadas no verão (1997 e 2000), em razão das condições hidrológicas ideais. A análise das amostras mostrou que a fauna bentônica é composta de 56 táxons, sendo o grupo dominante o de insetos com 48 táxons. Na distribuição do principal no curso do rio, três setores são reconhecidos: alto, médio e baixo no rio Cautín. Cada setor possui espécies de distribuição restrita e outro com ampla distribuição ao longo do rio. Esses padrões de distribuição parecem influenciar a concentração de oxigênio dissolvido, a temperatura, a distribuição altitudinal e a atividade antropocultural desenvolvida em todos os locais de amostragem. Finalmente, esta pesquisa fornece uma primeira abordagem biológica do rio Cautín e, de acordo com esses conhecimentos, um estudo posterior pode ser planejado em relação aos indicadores de qualidade da água e com base nas comunidades de macroinvertebrados.