scholarly journals Spider assemblages associated with different crop stages of irrigated rice agroecosystems from eastern Uruguay

2018 ◽  
Vol 6 ◽  
pp. e24974 ◽  
Author(s):  
Leticia Bao ◽  
Juaquín Ginella ◽  
Mónica Cadenazzi ◽  
Enrique Castiglioni ◽  
Sebastián Martínez ◽  
...  
Keyword(s):  
Cover Crop ◽  
Biological Diversity ◽  
Insect Pests ◽  
Rice Crop ◽  
Total Abundance ◽  
Irrigated Rice ◽  
Rotation System ◽  
Successful Group ◽  
Spider Abundance ◽  
Abundance And Diversity

The rice crop and associated ecosystems constitute a rich mosaic of habitats that preserve a rich biological diversity. Spiders are an abundant and successful group of natural predators that are considered efficient in the biocontrol of the major insect pests in agroecosystems. Spider diversity in different stages of the rice crop growth from eastern Uruguay was analysed. Field study was developed on six rice farms with rotation system with pasture, installed during intercropping stage as cover crop. Six rice crops distributed in three locations were sampled with pitfall and entomological vaccum suction machine. Sixteen families, representing six guilds, were collected. Lycosidae, Linyphiidae, Anyphaenidae and Tetragnathidae were the most abundant families (26%, 25%, 20% and 12%, respectively) and comprised more than 80% of total abundance. Other hunters (29%), sheet web weavers (25%) and ground hunters (24%) were the most abundant guilds. Species composition along different crop stages was significantly different according to the ANOSIM test. The results showed higher spider abundance and diversity along the crop and intercrop stages. This study represents the first contribution to the knowledge of spider diversity associated with rice agroecosystem in the country.

scholarly journals SPIDER DIVERSITY (ARACHNIDA: ARANEAE) OF THE TEA PLANTATION AT SERANG VILLAGE, KARANGREJA SUB-DISTRICT, DISTRICT OF PURBALINGGA

2017 ◽  
Vol 4 (2) ◽  
pp. 95
Author(s):  
Gianti Sibarani ◽  
Imam Widhiono ◽  
Darsono Darsono
Keyword(s):  
Insect Pest ◽  
Cropping System ◽  
Sampling Techniques ◽  
Total Abundance ◽  
Pesticide Application ◽  
Pest Population ◽  
Tea Plantation ◽  
Spider Community ◽  
Spider Abundance ◽  
Abundance And Diversity

Spiders are crucial in controlling insect pest population. The various cultivation managements such as fertilizer and pesticide application, weeding, pruning, harvesting, and cropping system affect their diversity. In the plantation, vegetation diversification has applied various practices, including monoculture, and intercropping, which influence the spider community. Thus, this study was intended to determine the spider abundance and diversity of the tea plantation, and the intercropping field (tea and strawberry) at Serang village, Karangreja Sub-District, District of Purbalingga. A survey and purposive sampling techniques were conducted, then the spiders were hand collected. Shannon-Wiener diversity (H’), Evenness (E), Simpson’s dominance (D), and Sorensen’s similarity (IS) indices were used to measure the spider diversity. The results revealed a total number of 575 individual spiders from 10 families, i.e., Araneae, Araneidae, Clubionidae, Linyphiidae, Lycosidae, Nephilidae, Oxyopidae, Salticidae, Tetragnathidae, Theridiidae, and Thomisidae. Araneidae was the most abundant in both fields. The total abundance of spiders in tea plantation (379 individuals), however, was greater than that in the intercropping field (196 individuals). Shannon-Wiener diversity reached H’= 1.873 in the plantation, and H’= 1.975 in the intercropping field.

scholarly journals Initial growth and competitive ability of yellow nutsedge and irrigated rice

2013 ◽  
Vol 31 (4) ◽  
pp. 813-821 ◽  
Author(s):  
N.R. Westendorff ◽  
D. Agostinetto ◽  
A.R. Ulguim ◽  
A.C. Langaro ◽  
L. Thürmer
Keyword(s):  
Leaf Area ◽  
Competitive Ability ◽  
Growth Cycle ◽  
Rice Crop ◽  
Initial Growth ◽  
Rice Cultivars ◽  
Replacement Series ◽  
Irrigated Rice ◽  
Yellow Nutsedge ◽  
Dry Biomass

Weeds cause significant reduction in the irrigated rice crop yield. Cyperus esculentus (yellow nutsedge) is adapted to irrigate environment. Information on the competitive ability of the weed to the culture, and their environmental adaptation, are scarce. In this study, we sought to determine the initial growth and competitive ability of yellow nutsedge and irrigated rice, as a function of cultivar growth cycle. Initial growth and competition studies were conducted in a randomized complete design in a greenhouse in the agricultural year 2010/11. For the initial growth study, the treatments consisted of a factorial combination of a biotype of yellow nutsedge and two rice cultivars in the function of the vegetative cycle (BRS Querência: early cycle - IRGA 424: intermediate cycle) and six evaluation times (10, 20, 30, 40, 50, and 60 days after emergence). Were evaluated: plant height, leaf area, aboveground dry biomass and root dry biomass. In the competitive ability study in the replacement series, the cultivar BRS Querência (early cycle) and yellow nutsedge were utilized and tested in different proportions of competition (100:0, 75:25, 50:50, 25:75, and 0:100). Were evaluated leaf area and aboveground dry biomass. In general, rice cultivars have an adaptive value equivalent to yellow nutsedge. IRGA 424 cultivar has less height than weed, becoming the weed control more important in this cultivar. For rice crop, intraspecific competition is more important, whereas for the weed, interspecific competition is the most pronounced.

scholarly journals Hubungan Rugositas Terumbu Karang terhadap Struktur Komunitas Ikan Corallivor dan Herbivor di Perairan Pemuteran, Bali

2020 ◽  
Vol 3 (1) ◽  
pp. 6
Author(s):  
Nidzar Muhammad Rafly ◽  
I Wayan Gede Astawa Karang ◽  
Widiastuti Widiastuti
Keyword(s):  
Coral Reefs ◽  
Reef Fishes ◽  
Herbivorous Fish ◽  
Strongly Correlated ◽  
Total Abundance ◽  
Underwater Visual Census ◽  
Herbivorous Fishes ◽  
The North ◽  
Fish Feeds ◽  
Abundance And Diversity

Reef fishes are the highest number of organisms that can be found in coral reefs in which the abundance depends on the healthy of this ecosystem. Reef fishes are mainly consisted of corallivorous and herbivorous fish. Corralivorous fish feeds on coral polyps while herbivorous fish feeds on algae. Therefore these fishes are an important indicators in the resilience of coral reefs. Studies showed that its abundance is strongly correlated with reef’s conture (rugosity). Pemuteran waters is one of developing tourists attraction in the north Bali island. However, the data of reef fishes and coral reefs in Pemuteran waters remain limited. Therefore, this research aimed to study the reef` condition and rugosity in Pemuteran waters, also to examine the correlation between reefs fishes and reefs rugosity in this area. There were four stations according to purposive sampling method. Data of corallivorous and herbivorous fishes were collected by using the underwater visual census with a 40 m2 transect. Reef rugosity index were determined by using chain transect method. Results showed that reef rugosity in Pemuteran waters was in the medium to high category. Reef rugosity has strong correlation with the total abundance and diversity of corallivorous fishes. However, reef rugosity was only strong correlated with the total abundance but not with the diversity of herbivorous fishes.

scholarly journals Abundance and diversity of soil arthropods and fungi in shelterbelts integrated with pastures in the central tablelands of New South Wales, Australia

2012 ◽  
Vol 58 (No. 12) ◽  
pp. 560-568 ◽  
Author(s):  
E.W. Mbuthia ◽  
J.H. Shariff ◽  
A. Raman ◽  
D.S. Hodgkins ◽  
H.I. Nicol ◽  
...  
Keyword(s):  
Organic Matter ◽  
Biological Diversity ◽  
Soil Depth ◽  
Soil Surface ◽  
Early Spring ◽  
Late Winter ◽  
Soil Arthropods ◽  
South Wales ◽  
Abundance And Diversity ◽  
The Relationship

Shelterbelts are important for the sustainability of agriculture because they provide a variety of benefits to farmers and the society. Several published papers demonstrate that integration of shelterbelts with agroecosystems offers positive outcomes, such as better yield, more congenial microclimate, and greater organic matter levels. Nonetheless, soil biological diversity, the driver of greater organic matter levels, has not been convincingly tested and verified yet. In addressing this gap, we measured abundance and diversity of populations of arthropods and fungi in three<br />11-year old shelterbelts integrated with pasture to determine whether a correlation exists between the abundance of and diversity in populations of arthropods and fungi in two seasons: late autumn-early winter (May&ndash;June 2011) and late winter-early spring (August&ndash;September 2011). Litter from the soil surface and soil from two depths were sampled at increasing distance from the midpoint of shelterbelts for the extraction of arthropods and isolation culturing of fungi. The relationship among distance, depth and biodiversity of different groups of arthropods and fungi was analysed using linear regression. We found that over both seasons arthropod abundance in the litter and soil declined with increasing distance from the midpoint of the shelterbelts, and with soil depth. However, fungi abundance in either season was not affected by proximity to the shelterbelt but increased with greater soil depth. Distance from the shelterbelt midpoints did not bear an impact on the diversity richness of both arthropods and fungi.

scholarly journals Seascape context modifies how fish respond to restored oyster reef structures

2019 ◽  
Vol 76 (4) ◽  
pp. 1131-1139 ◽  
Author(s):  
Ben L Gilby ◽  
Andrew D Olds ◽  
Christopher J Henderson ◽  
Nicholas L Ortodossi ◽  
Rod M Connolly ◽  
...  
Keyword(s):  
Species Richness ◽  
Fish Species ◽  
Fish Assemblages ◽  
Oyster Reef ◽  
Pivotal Role ◽  
Oyster Reefs ◽  
Total Abundance ◽  
Fish Recruitment ◽  
Abundance And Diversity ◽  
Species Specific

Abstract The seascape context of coastal ecosystems plays a pivotal role in shaping patterns in fish recruitment, abundance, and diversity. It might also be a principal determinant in structuring the recruitment of fish assemblages to restored habitats, but the trajectories of these relationships require further testing. In this study, we surveyed fish assemblages from 14 restored oyster reefs and 14 control sites in the Noosa River, Queensland, Australia, that differed in the presence or absence of seagrass within 500 m, over four periods using baited cameras. Fish assemblages at oyster reefs differed from those at control sites, with higher species richness (1.4 times) and more individuals of taxa that are harvested by fishers (1.8 times). The presence or absence of seagrass nearby affected the abundance of a key harvestable fish species (yellowfin bream Acanthopagrus australis) on oyster reefs, but not the overall composition of fish assemblages, species richness, or the total abundance of harvestable fishes overall. These findings highlight the importance of considering species-specific patterns in seascape utilization when selecting restoration sites and setting restoration goals, and suggest that the effects of restoration on fish assemblages might be optimized by focusing efforts in prime positions in coastal seascapes.

scholarly journals Phosphorus Availability for Irrigated Rice Cultivated Under No-Tillage and Different Phosphate Sources

2018 ◽  
Vol 10 (5) ◽  
pp. 276
Author(s):  
Magali De Ávila Fortes ◽  
Rogério Oliveira de Sousa ◽  
Algenor da Silva Gomes ◽  
Fabiana Schmidt ◽  
Walkyria Bueno Scivittaro ◽  
...  
Keyword(s):  
Residual Effect ◽  
Rice Crop ◽  
Residual Effects ◽  
P Availability ◽  
No Tillage ◽  
Irrigated Rice ◽  
Soil P ◽  
Phosphate Fertilization ◽  
Tillage System ◽  
Yield Responses

The objective of this work was to evaluate the response of irrigated rice to phosphate fertilization using triple superphosphate (TSP) and Arad phosphate rock (APR), and the phosphate residual effects of upland crops in no-tillage system on the following rice crop. Also, it aimed to evaluate the efficiency of Mehlich-1 and anion exchange resin as soil P extractors. Two experiments were conducted in Albaqualf soil under irrigated conditions in the southern region of Rio Grande do Sul State. The experiments were designed as random blocks with four replications and the treatments were displayed as a 2 × 2 factorial (TSP and APR, with and without annual P application as TSP). No yield responses to phosphate were observed. Phosphate fertilization performed on upland crops (maize and soybeans) presented a residual effect on the rice crop even after four years of consecutive cropping under no-tillage. The extractors Mehlich-1 and AER were equally efficient in the evaluation of P availability for the rice crop. P content values obtained by both methods did show a significant correlation with accumulated plant P. The APR presents a similar performance as the TSP in regard to phosphate nutrition in irrigated rice when rotated with upland crops under no-tillage system.

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