scholarly journals Effect of land-use types on the ecomorphological structure of fish assemblage in distinct mesohabitats of neotropical streams

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Leonardo Antunes Pessoa ◽  
Matheus Tenório Baumgartner ◽  
Marcelo Percilio Santana Junior ◽  
João Paulo Alves Pagotto ◽  
Luiz Gustavo Antunes Pessoa ◽  
...  

Abstract The use and occupation of land by human population substantially influence environmental variables and fish assemblage in streams. However, there is little knowledge on how these changes affect the ecomorphological structure of fish assemblage in mesohabitats. Therefore, we aim to assess whether the land-use types affect the ecomorphological structure of fish assemblage in distinct mesohabitats. Environmental and ichthyofaunistic data were collected in three mesohabitats (rifles, runs, and pools) of five rural and five urban streams. Twenty-one ecomorphological indices were obtained from the mean of linear morphological measurements and areas of the fishes. Subsequently, the Euclidean distance was calculated, based on the ecomorphological indices, between each pair of species, to measure the ecomorphological distances for the mesohabitats of the rural and urban streams. The results show that the urban environment is more harmful to streams than the rural one, due to changes in the environmental variables and decrease in species richness. The main environmental changes found in urban streams were the decrease in canopy cover by riparian vegetation and dissolved oxygen, and the increase in electrical conductivity and bed silting. Also, there was a significant decrease in the morphological similarity between fish species in the mesohabitats of urban streams compared to rural ones. Therefore, we can conclude that the urban environment leads to the loss of morphologically similar fish species in the mesohabitats, with only a few functionally distinct species remaining.

2016 ◽  
Vol 65 (1) ◽  
pp. 103 ◽  
Author(s):  
Igor David Da Costa ◽  
Vanessa Rocha

Igarapés are Amazonian streams that are extremely susceptible to environmental changes. Due to the rapidly occurring riparian land use changes, and the several impacts these may have on fish assemblages, it is highly valuable to describe and understand the current relationships between these assemblages and the local environmental conditions, especially in barely know areas. In this research, we studied the taxonomic composition and fish assemblage attributes variation in three streams with different riparian conservation conditions: forest, intermediate and pasture. Samplings were performed every two months from October 2011 to September 2012, in three 1st order streams in the Machado River Basin, Rondônia. Fish were collected using trawls (seine net with a mesh size of 2 mm) and dip nets (2 mm mesh) along the entire stretch; the obtained samples were preserved and identified per site type. A total of 2 141 fish specimens belonging to 59 species, 17 families and five orders were recorded. Unlike the intermediate and pasture streams, the forest stream showed a high richness and low abundance. The forested stream exhibited the highest diversity and evenness value, and had low dominance, unlike the other streams. The variance partitioning and partial Redundancy Analysis (pRDA) indicated that assemblage composition was significantly explained by the environmental variables such as: depth, water velocity, pteridophytes and grasses, but not by spatial predictors. The non-metric multidimensional scaling (NMDS) analysis showed that intermediate and pasture streams separated from the forested stream. We concluded that both, the stream environmental variables and fish assemblage attributes were influenced by the different conservation status and land cover. Given the influence of regional processes, which have a pervasive role in local fish assemblages, land use at the watershed scale is important, especially to explain the higher richness and diversity found in forested streams.


Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 152 ◽  
Author(s):  
Da-Yeong Lee ◽  
Dae-Seong Lee ◽  
Mi-Jung Bae ◽  
Soon-Jin Hwang ◽  
Seong-Yu Noh ◽  
...  

Odonata species are sensitive to environmental changes, particularly those caused by humans, and provide valuable ecosystem services as intermediate predators in food webs. We aimed: (i) to investigate the distribution patterns of Odonata in streams on a nationwide scale across South Korea; (ii) to evaluate the relationships between the distribution patterns of odonates and their environmental conditions; and (iii) to identify indicator species and the most significant environmental factors affecting their distributions. Samples were collected from 965 sampling sites in streams across South Korea. We also measured 34 environmental variables grouped into six categories: geography, meteorology, land use, substrate composition, hydrology, and physicochemistry. A total of 83 taxa belonging to 10 families of Odonata were recorded in the dataset. Among them, eight species displayed high abundances and incidences. Self-organizing map (SOM) classified sampling sites into seven clusters (A–G) which could be divided into two distinct groups (A–C and D–G) according to the similarities of their odonate assemblages. Clusters A–C were characterized by members of the suborder Anisoptera, whereas clusters D–G were characterized by the suborder Zygoptera. Non-metric multidimensional scaling (NMDS) identified forest (%), altitude, and cobble (%) in substrata as the most influential environmental factors determining odonate assemblage compositions. Our results emphasize the importance of habitat heterogeneity by demonstrating its effect on odonate assemblages.


2019 ◽  
Vol 31 ◽  
Author(s):  
Leandro Schlemmer Brasil ◽  
Ana Luiza-Andrade ◽  
Tiago Borges Kisaka ◽  
Paulo Ilha ◽  
Francisco Diogo Rocha Sousa

Abstract: Aim Our objective in this study is to understand Cladocera species distribution along an environmental gradient in forest and cropland landscapes in the southern Amazon. Methods We collected Cladocera communities and environmental variables from five streams and verified their associations with a Redundancy Analysis. Results Acroperus tupinamba, Alonella dadayi e Kisakiellus aweti were mostly associated to sites with higher canopy cover. Anthalona neotropica, Anthalona verrucose and Flavalona iheringula occurred exclusively in site with more thalweg depth. Conclusions If these results are confirmed Cladocera stream communities are affected by changes in land use. Further studies in this line are extremely necessary to reduce this knowledge gap.


<em>Abstract.</em>—Iowa leads the nation in percentage of land area converted to cropland, with a resulting negative impact on streams. We examined physical habitat, land use, and fish assemblage data from 37 second- to sixth-order stream sites, representing 7 of the 10 ecoregions within Iowa. Physical habitat conditions varied widely among sites, with sand dominating substrate composition. A nonmetric multidimensional scaling ordination of physical habitat variables suggested a pattern of among-site similarities defined by a stream size axis, an axis contrasting sites dominated by either woody or rocky fish cover, and an axis characterizing degree of riparian canopy coverage. Bluntnose minnow <em>Pimephales notatus </em>and sand shiner <em>Notropis stramineus </em>were the most abundant fish species, followed by green sunfish <em>Lepomis cyanellus </em>and common carp <em>Cyprinus carpio</em>. These four species were collected in more than 80% of the sites. Fish species richness at sites averaged 22, ranging from 6 to 38, and fish index of biotic integrity (IBI) at sites averaged 47 (fair), ranging from 21 (poor) to 96 (excellent). Species richness and IBI were highest at sites characterized by rocky fish cover and relatively coarse substrates. Values for several physical habitat and land use variables were significantly different between sites with IBI ≤ 30 (fair) and sites with IBI ≥ 50 (good). We found a general pattern of IBI, species richness, total fish abundance, and width-to-depth ratio decreasing from the northeast to the southwest ecoregions, and percentage of unvegetated banks and bank slope increasing from northeast to southwest. Stable and vegetated banks, wide stream channels with coarse substrates, and rocky fish cover were associated with high biotic condition; while unvegetated and eroding banks, and deep channels with predominantly fine substrates were associated with lower biotic condition. Land use was calculated at three spatial scales: catchment, network riparian buffer, and local riparian buffer. We found few relationships of fish assemblages with land use, potentially due to sampling design and the pervasiveness of agriculture across Iowa. There is substantial variation among physical habitat, land use, and fish assemblage conditions across Iowa, due to a combination of geology, climate, zoogeography, and human alteration.


Pedosphere ◽  
2020 ◽  
Vol 30 (2) ◽  
pp. 201-213 ◽  
Author(s):  
Md. Saiful ISLAM ◽  
Md. Kawser AHMED ◽  
Md. Habibullah Al-MAMUN ◽  
Dennis Wayne EATON

<em>Abstract.</em>—Data collected as part of two studies to examine the influences of landscape modification on the ecology of three coastal Southern California river systems—the Calleguas Creek, Malibu Creek, and Santa Clara River watersheds—provided the opportunity to examine relations between urbanization and fish assemblages in Southern California coastal streams. Fish were collected at 63 sites from 1999 to 2001. Watershed land use was determined and classified into three land use types: agriculture, developed, and open space. Seven fish assemblage metrics were examined, including species richness, number of native and alien species, total fish abundance, percent abundance of native and alien species, and percent abundance of arroyo chub <em>Gila orcuttii</em>. Ten fish species were collected, and arroyo chub was the only species collected in all three watersheds. Native species included arroyo chub, threespine stickleback <em>Gasterosteus aculeatus</em>, steelhead <em>Oncorhynchus mykiss</em>, and Pacific staghorn sculpin <em>Leptocottus armatus</em>. There were no significant differences in fish assemblage metrics among the three land-use types. Both wetted stream width and depth were significantly related to native fish abundance. Results from this study suggest that the relatively species poor fish assemblages of Southern California may not be sensitive to watershed land use disturbance, but may be sensitive to local hydrologic conditions.


2018 ◽  
Vol 10 (12) ◽  
pp. 4730 ◽  
Author(s):  
Siqin Tong ◽  
Zhenhua Dong ◽  
Jiquan Zhang ◽  
Yongbin Bao ◽  
Ari Guna ◽  
...  

Land use/cover change (LUCC) is one of the major environmental changes and has become a hot topic in the study of global change. Based on four land use classification maps, this study used the intensity analysis method to quantitatively monitor the land use changes which occurred in Inner Mongolia during 1980–2015. The results showed that changes occurred although the trends of corresponding land use types were different (increase or decrease), and the land use changes had an obvious increasing or decreasing trend before and after 2000, respectively. Generally, woodland, high-coverage grassland, and moderate-coverage grassland decreased and the other land use types increased during 1980–2015. In addition, the changes had great differences in spatial distribution. The area of grassland had the largest decrease, indicating that the quality of grassland has declined in Inner Mongolia. The variation rate of land use in 1980–1990 was faster than the rates in 1990–2000 and 2000–2015.


2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Marjorie D. delos Angeles ◽  
Ailene A. Alcala ◽  
Inocencio E. Buot Jr.

Changes are evident in fern species richness, composition, and abundance as a result of environmental changes caused by forest conversion to various land use types. This study identified fern species and described its distribution pattern with reference to ecological parameters obtained from various land use types across the northeastern slope of Mt. Makiling Forest Reserve, Los Baños, Philippines. The plot technique was employed using a 20x20 meter quadrat. Three 5x2 subquadrats were randomly distributed within the established quadrat. Cluster and ordination analysis were used and edaphic factors were analyzed. Fern specimens were identified (sensu PPG) and measured. Samples were collected for herbarium vouchers and were deposited at the Plant Biology Division Herbarium, University of the Philippines Los Baños (PBDH). Cluster analysis revealed six land use types: buffer, agroforest, agri-farm, roadside, mahogany, and forest. Twenty-nine (29) fern species belonging to 23 genera from 14 families were recorded across the different land use types. Among the land use types, the forest had the highest fern species richness (13) and the agri-farm and Mahogany had the least (6). Canonical correspondence analysis indicated that moisture, OM, pH, and CEC were significant explanatory drivers of fern distribution especially in the Mahogany and Agroforest land use type. Understanding the fern community patterns and edaphic factors in Mt. Makiling would aid in its conservation planning.


Author(s):  
Hayley S. Gotwald ◽  
J. Brian Alford

We evaluated the potential of using fish species and functional traits as indicators of land use impacts to fish assemblages. We used environmental data collected at multiple spatial scales (local, reach, and upstream catchment) for 19 tributary and main stem sites in the Nolichucky River watershed in Tennessee. Canonical correspondence analyses showed that temperature, elevation, specific conductivity, sediment yield, impervious surfaces, and row crop cover at the catchment scale were strongly associated with fish assemblage structure, as well as forest cover from all three spatial scales. Blocked indicator species analysis, with stream size as the block, showed that significantly strong indicators of the least-impacted riparian land use condition (&ge;60% forest cover) were Saffron Shiner (Notropis rubricroceus), Rainbow Trout (Oncorhyncus mykiss), Longnose Dace (Rhynichthys cataractae), Creek Chub (Semotilus atromaculatus), and Mottled Sculpin (Cottus bairdi). Traits indicative of the least-impacted sites were the herbivorous trophic guild, mean female age-at-maturity, longevity, rock-gravel spawners, montane geology and pelagic swimmers. Specific conductivity was strongly related to multiple catchment-scale land use variables, and was a strong local-scale influence on fish assemblage structure. Our results show promise for using a relatively common but endemic southern Appalachian fish species, the Saffron Shiner, as an indicator for land-use related impacts to these streams.


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