Effect of the riparian vegetation removal on the trophic network of Neotropical stream fish assemblage

The study of the diet of fish is an important tool to assess different levels of environmental degradation, since the availability of food in the environment is a key factor for the fish occurrence. The removal of riparian vegetation usually degrades environmental quality, as this vegetation has an important role in providing energy to the ecosystem. This study investigates the effects of the removal of riparian vegetation on the fish assemblage trophic network. The study was carried out in two stretches of a southeastern Brazilian stream, one in a forest fragment and another in a pasture, during the wet and dry seasons of 2014. We analyzed the items consumed by each fish species using the frequency of occurrence and area of each item, which were combined to calculate the alimentary index, which was used to determine the food niche overlap of the fish and the specialization index of the trophic network. Aquatic Hexapoda, vegetal debris and organic matter dominated the trophic network of the two stretches. We detected higher values of food niche overlap in the forested stretch and more complex trophic networks in the pasture stretch. We found few seasonal variations in the items consumed and calculated indices in both stretches studied. The presence of grass on the banks in the pasture stretch and the importation of food resources from the upstream area may have provided a higher diversity of resources and consequently showed a more complex trophic network when compared to the forested stretch.

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Rising ecosystem water demand exacerbates the lengthening of tropical dry seasons

10.21203/rs.3.rs-218770/v1 ◽

2021 ◽

Author(s):

Hao Xu ◽

Xu Lian ◽

Ingrid Slette ◽

Hui Yang ◽

Yuan Zhang ◽

...

Keyword(s):

Water Demand ◽

Potential Evapotranspiration ◽

Central Africa ◽

Dry Season ◽

Land Area ◽

Key Factor ◽

Dry Seasons ◽

The Tropics ◽

Factor Governing

Abstract The timing and length of the dry season is a key factor governing ecosystem productivity and the carbon cycle of the tropics. Mounting evidence has suggested a lengthening of the dry season with ongoing climate change. However, this conclusion is largely based on changes in precipitation (P) compared to its long-term average (P ̅) and lacks consideration of the simultaneous changes in ecosystem water demand (measured by potential evapotranspiration, Ep, or actual evapotranspiration, E). Using several long-term (1979-2018) observational datasets, we compared changes in tropical dry season length (DSL) and timing (dry season arrival, DSA, and dry season end, DSE) among three common metrics used to define the dry season: P < P ̅, P < Ep, and P < E. We found that all three definitions show that dry seasons have lengthened in much of the tropics since 1979. Among the three definitions, P < E estimates the largest fraction (49.0%) of tropical land area likely experiencing longer dry seasons, followed by P < Ep (41.4%) and P < P ̅ (34.4%). The largest differences in multi-year mean DSL (> 120 days) among the three definitions occurred in the most arid and the most humid regions of the tropics. All definitions and datasets consistently showed longer dry seasons in southern Amazon (due to delayed DSE) and central Africa (due to both earlier DSA and delayed DSE). However, definitions that account for changing water demand estimated longer DSL extension over those two regions. These results indicate that warming-enhanced evapotranspiration exacerbates dry season lengthening and ecosystem water deficit. Thus, it is necessity to account for the evolving water demand of tropical ecosystems when characterizing changes in seasonal dry periods and ecosystem water deficits in an increasingly warmer and drier climate.

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Summer food composition and food niche overlap of the raccoon dog, red fox and badger in Finland

Ecography ◽

10.1111/j.1600-0587.1998.tb00436.x ◽

1998 ◽

Vol 21 (5) ◽

pp. 457-463 ◽

Cited By ~ 64

Author(s):

Kaarina Kauhala ◽

Paula Laukkanen ◽

Inez Rége

Keyword(s):

Red Fox ◽

Niche Overlap ◽

Food Composition ◽

Raccoon Dog ◽

Food Niche

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Diets of three sympatric Neotropical small cats: Food niche overlap and interspecies differences in prey consumption

Mammalian Biology ◽

10.1016/j.mambio.2010.09.001 ◽

2011 ◽

Vol 76 (3) ◽

pp. 308-312 ◽

Cited By ~ 24

Author(s):

José E. Silva-Pereira ◽

Rodrigo F. Moro-Rios ◽

Diego R. Bilski ◽

Fernando C. Passos

Keyword(s):

Niche Overlap ◽

Prey Consumption ◽

Interspecies Differences ◽

Food Niche

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

Brazilian Journal of Biology ◽

10.1590/s1519-69842007000200002 ◽

2007 ◽

Vol 67 (2) ◽

pp. 191-195 ◽

Cited By ~ 6

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.

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Presence of riparian vegetation increases biotic condition of fish assemblages in two Brazilian reservoirs

Acta Limnologica Brasiliensia ◽

10.1590/s2179-975x4514 ◽

2015 ◽

Vol 27 (3) ◽

pp. 289-300 ◽

Cited By ~ 2

Author(s):

Fabio Cop Ferreira ◽

Ursulla Pereira Souza ◽

Miguel Petrere Junior2

Keyword(s):

Fish Assemblage ◽

Riparian Vegetation ◽

Habitat Complexity ◽

Fish Assemblages ◽

Biotic Integrity ◽

Wood Structures ◽

Paulo State ◽

Composition And Structure ◽

Lakes And Reservoirs ◽

Metric Selection

Abstract The riparian vegetation in lakes and reservoirs is source of course wood structures such as trunks and branches and is used as sheltering, spawning and foraging habitats for fishes. The reduction of these submerged structures can thus, affect the composition and structure of fish assemblages in reservoirs. Aim To evaluate the influence of riparian vegetation on the biotic condition of fish assemblage by adapting the Reservoir Fish Assemblage Index (RFAI) to two reservoirs in the Upper Paranapanema river basin, São Paulo State, Brazil. Methods The RFAI was adapted from metrics related to the functional characteristics and composition of fish assemblages through a protocol of metric selection and validation, and to its response to the presence of riparian vegetation. Results The final RFAI was composed by nine metrics, been lower in sites without riparian vegetation as consequence of the predominance of larger individuals and the percent of piscivorous and detritivorous fishes. Conclusions These results suggest that increasing shore habitat complexity in reservoirs by maintaining riparian vegetation increases fish biotic integrity.

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Food niche overlap between two sympatric leaf-litter frog species from Central Amazonia

Zoologia (Curitiba) ◽

10.1590/s1984-46702012000100013 ◽

2012 ◽

Vol 29 (1) ◽

pp. 95-98 ◽

Cited By ~ 9

Author(s):

Leandro Talione Sabagh ◽

Renata da Silva Mello ◽

Carlos Frederico Duarte Rocha

Keyword(s):

Leaf Litter ◽

Niche Overlap ◽

Central Amazonia ◽

Frog Species ◽

Food Niche

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Nymphal feeding habits of two Anacroneuria species (Plecoptera, Perlidae) from Sierra Nevada de Santa Marta, Colombia

Journal of Limnology ◽

10.4081/jlimnol.2018.1858 ◽

2018 ◽

Vol 78 (1) ◽

Cited By ~ 1

Author(s):

Yesely M. Hurtado ◽

Cesar E. Tamaris-Turizo ◽

Manuel J. López Rodriguez ◽

J. Manuel Tierno de Figueroa

Keyword(s):

Sierra Nevada ◽

Rainy Season ◽

Feeding Habits ◽

Niche Overlap ◽

Trophic Niche ◽

Freshwater Ecosystems ◽

Use Of Resources ◽

Trophic Resources ◽

Tropical Areas ◽

Dry Seasons

The knowledge of the diet of aquatic insects is important to assess the use of resources and overlap of trophic niche between species, as well as to understand their role in the food web of the freshwater ecosystems they inhabit. This is particularly necessary in tropical areas where information on this topic is scarce. The aim of the present work is to describe the feeding habits of the species Anacroneuria marta Zúñiga and Stark, 2002 and Anacroneuria caraca Stark, 1995 in the middle section of the Gaira River (Sierra Nevada de Santa Marta, Colombia). We performed three samplings during the rainy and dry seasons in the two main different microhabitats of the reach (leaf packs and gravel) in 2014. The diet of a total of 87 and 90 individuals of A. caraca and A. marta, respectively, was studied. With this information, niche breadth for each species and niche overlap between them in terms of trophic resources were calculated. The main trophic resource for both species in the dry and rainy season was the animal matter. In the dry season, FPOM was also important in the diet of A. caraca, and A. marta ingested a great quantity of CPOM in the rainy season. Larvae of Trichoptera, were the most ingested prey in both species, followed by Chironomidae, Coleoptera Hydrophilidae, and Ephemeroptera. No differences in diet between both species were detected, so this could favor the niche overlap in terms of trophic resources and could lead to competition between them. The possible ecological scenarios are discussed.

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