Beginning Of Rainy Season Research Articles

Differences in climate-growth relationships between two tree species that co-occur in a seasonally dry tropical forest in Northeastern Brazil

Seasonally dry tropical forests are an important global climate regulator and represent one of main drivers of carbon sink dynamics. However, projections of climate change suggest future productivity losses and negative impacts on forest functioning. Understanding the interaction between climate variability and tree growth responses between species with different growth strategies represents a crucial challenge to forecast ecosystem functioning in the future. Here we used tree ring chronology to evaluate changes in growth and climate sensitivity of two tropical tree species that co-occur in a seasonally dry tropical forest in Brazil: Cedrela odorata and Ceiba glaziovii. Using Pearson correlations and linear regressions we explored how growth variability is correlated with local (precipitation, temperature) and global (ocean temperature and El Niño Southern Oscillation - ENSO) climatic factors. Tree growth was closely related with precipitation in C. odorata (r = 0.59) and C. glaziovii (0.24). Differences were found at monthly level, which C. odorata showing greater sensitivity in the beginning of rainy season. The South Atlantic Temperature was positively correlated with C. odorata, while ENSO was negatively correlated. Our results showed a dominant effect of precipitation on tree growth and suggest that are different growth strategies among species, which C. odorata being the most sensitive to drought and C. glaziovii more adapted with parenchyma in trunk. Therefore, C. odorata is probably more vulnerable to the deleterious effects of future climate change than C. glaziovii. Our findings highlight the importance of understanding the climate sensitivity of different seasonally dry tropical forest species, which is critical to predicting carbon dynamics in tropical regions. These also reveal that differences in sensitivity must be considered when prioritizing conservation measures for seasonally dry tropical forests.

Effect of Zai Pit Technology on the Infiltration Capacity of the Soil

Increase in population and depletion of ground water resources are the major problems for food security and stability. Irrigated lands now produce only 4% of the food supply which doesn’t meet the required demand. Zai pit technology provides a window of opportunity for farmers to improve crop performance in harsh & changing climate by trapping rain water and retains moisture by allowing water long enough to infiltrate. The present study was carried out at the College of Agricultural Engineering, Madakasira, which was located in Anantapuram district, Andhra Pradesh. The methodology follows estimation of infiltration rate for both Zai pit technology and furrow irrigation method. The Zai pit consists of dug holes excavated in grids, with a diameter of 15-20 cm,70 to 80 cm spacing, and a depth of 10-15 cm or more, filled with manure. The spacing of pits within a row, as well as the space between rows of pits, varies between 60 and 100 cm. Pits were prepared and organic manure was placed at the beginning of rainy season. In Zai pit technology, infiltration rate of the soil increased from 1.45 to 2.25 cm/hr whereas in furrow irrigation, it was decreased from2.24 to 1.1 cm/hr. In Zai pit technology, the organic manure was decomposed properly and the micro-organisms present in the soil make way to reach the organic manure and thus the micro pores in the soil increased whereas in furrow irrigation the soil was compacted which decreases the infiltration rate. This may be the reason behind the increasing of infiltration in the Zai pit technology. Thus, Zai pit technology reactivates biological activities in the soil and eventually leads to an improvement in soil structure and converts barren lands to cultivated lands.

English

The camel is one of the most vital domestic animals species for pastoralist livelihood as much as their blood circulation. The annual camel milk production of Ethiopia in 2018 is estimated to be 176113 tones. Camel produces considerable amount of milk and for long period of time than other milk producing animals under harsh conditions. Meat quality is largely age dependent and as other animals, good meat is from young slaughtered camel. Camel herd sizes per household vary from few heads to several hundreds. The proportion of male to female animals in breeding herd is not equal because of higher number of female camels in the herd as compared to male camels. During the dry season all female camels are shifted to areas with better feed accessibility but male camels are usually reared around settlement area. Mostly male camels are used for transportation of commodities. Breeding management comprises of selection of best animals for next generation and/or culling of the worst animals from the herd, and controlled breeding. Camels start breeding at the end of the dry season and the beginning of rainy season and continue thought the season. Camel can be categorized under seasonal breeding animal species. Prevalence of disease in pastoral areas of Ethiopia is principal constraint of the pastoralist in their camel production. There are inadequate researches and reports have been conducted on potential of camel production and management system in the country. Therefore, this review paper is going to present potential of camel production and management practices in Ethiopia. Key words: Camel, management practices, production potential.  

Leaching Treatment of Acid Sulphate Soil and Crop Adaptation Test under Micro Scale Condition

Agricultural problem on acid sulphate soil is related to high concentration of iron and aluminum which can be toxic to crops. The research objective was to determine soil leaching intensity or frequency effect on decreasing iron and aluminum concentration. Results from this research information can be used to develop field strategy in order to determine time and period for land leaching. Moreover, crop adaptation toward leached soil was conducted on corn crop. Experiment was conducted in laboratory of soil physics department of soil science. Duration of leaching was set up in the 5, 10, 15 days. The pH of iron and aluminum was analyzed before treatment. Iron content was at 11.58 ppm and pH was at 3.29. The result showed that the leaching option had highly significant effect on the increasing pH and reducing iron content. The pH was increase at 3.85, 4.07, 4, 26 and 4.34 respectively for 5, 10 and 15 days of leaching. It was also followed by reducing iron content of 9.29, 7.08 and 5.06 respectively for 5, 10 and 15 days of leaching. Within 15 day (two weeks duration) it was sufficient time to facilitate leaching process in the field. Climatic data showed that the rainfall was available during land preparation stage (November for first crop and March for second crop). On the other hand, the drainage facility should be developed in tertiary block to leach out the toxic element in the roots zone. This process should be done in the beginning of rainy season. Adaptation toward corn crop showed that 5 times leaching treatment was sufficient to provide good environment for crop’s growth.

Spatio-temporal Variation of Harmful Planktonic Microalgae and Cyanobacteria Along the Central Coast of Campeche, Southeastern Gulf of Mexico.

To describe the phytoplankton species composition, spatio-temporal distribution and habitats during different seasons along the central coast of the state of Campeche, Mexico, southeastern Gulf of Mexico, eight shallow-water (ca 1m) sites from the city of Campeche Southwest to Villamar were monitored monthly from September 2016 to June 2017 by taking water-bottle samples. Average water temperature varied between 22.2 and 30.9°C and average salinity between 26.6 and 35.0. The Kolmogorov-Smirnov test, the Bartlett's test and canonical correspondence analyses were applied. Sixteen potentially harmful microalgal species were found: five species are bloom-forming, nine are potentially toxic to humans, and two affect aquatic organisms. At all sampling sites, massive algal proliferations occurred in June (beginning of rainy season) caused by the dinoflagellates Heterocapsa sp. (2.6 × 105cells/L) and Blixaea quinquecornis (2.0 × 104 cells/L) and from October to March (windy season) by the cyanobacterium Trichodesmium sp. (2.6 × 105cells/L).

Abbatoir Survey of Intestinal Parasites among Sheep in Katsina State, Nigeria

Faecal samples collected from seven hundred sheep brought for slaughter in some abattoirs in six Local Government Areas of Katsina State were examined for presence of intestinal parasites. The samples were examined for eggs of parasites using direct smear and formol-ether concentration technique. The overall prevalence was 236(33.7%). The cestode identified was Moniezia sp. 16(2.3%). The coccidian oocyts had a prevalence of 8.6%. The nematodes identified were Strongyle sp. 116(16.6%) and Trichuris sp. 17(2.4%), while the only trematode identified was Fasciola sp. 17(2.4%). Factors such as sex, age and breed of the sheep were found not to significantly influence the prevalence of infection (P>0.05). The results of the study showed that season was a factor which can significantly influenced the prevalence of infection among sheep in the study area (P<0.05). The study identified high prevalence of intestinal parasites among sheep slaughtered in the six abattoirs. Therefore, strategic control approach by using effective broad spectrum chemotherapeutics especially at the beginning of rainy season to reduce the burden of infection is recommended.

Rainfall-Induced Variation of Seismic Waves Velocity in Soil and Implications for Soil Response: What the ARGONET (Cephalonia, Greece) Vertical Array Data Reveal

ABSTRACTWe apply interferometry by deconvolution to compute the shear-wave velocity in shallow sediments (0–83.4 m) based on earthquake records from a vertical accelerometric array (ARGOstoli Network [ARGONET]) on Cephalonia Island, Greece. Analysis of the time variation of measured values reveals a cyclical pattern, which correlates negatively to rainfall and a soil moisture proxy. The pattern includes a sharp reduction in velocity at the beginning of rainy seasons and a gradual rise toward dry periods, the overall variation being around 20%–25% within the shallowest depth interval examined (0–5.6 m) and estimated to reach 40% within the top 2 m. The variation itself and its amplitude are verified by surface-wave dispersion analysis, using ambient vibration data. Synthetic standard spectral ratios suggest that this seasonal effect leaves an imprint on soil response, causing differences in the level of high-frequency ground motion between dry and rainy seasons, and this is verified by earthquake records. Furthermore, the near-surface velocity decrease due to soil saturation can be of the same order of magnitude as the nonlinear coseismic variation, masking the physical process of the nonlinear response of the site due to weak-to-strong-motion shaking. Thus, seasonal variations of seismic-wave velocities in shallow sediments may be important for a number of site-effect related topics, such as high-frequency ground-motion variability, soil anisotropy, kappa measurements, nonlinear site response, and so on.

Variation of prevalence of malaria, parasite density and the multiplicity of Plasmodium falciparum infection throughout the year at three different health centers in Brazzaville, Republic of Congo

BackgroundIn the Republic of Congo, hot temperature and seasons distortions observed may impact the development of malaria parasites. We investigate the variation of malaria cases, parasite density and the multiplicity of Plasmodium falciparum infection throughout the year in Brazzaville.MethodsFrom May 2015 to May 2016, suspected patients with uncomplicated malaria were enrolled at the Hôpital de Mfilou, CSI « Maman Mboualé», and the Laboratoire National de Santé Publique. For each patient, thick blood was examined and parasite density was calculated. After DNA isolation, MSP1 and MSP2 genes were genotyped.ResultsA total of 416, 259 and 131 patients with suspected malaria were enrolled at the CSI «Maman Mboualé», Hôpital de Mfilou and the Laboratoire National de Santé Publique respectively. Proportion of malaria cases and geometric mean parasite density were higher at the CSI «Maman Mboualé» compared to over sites (P-value <0.001). However the multiplicity of infection was higher at the Hôpital de Mfilou (P-value <0.001).At the Laboratoire National de Santé Publique, malaria cases and multiplicity of infection were not influenced by different seasons. However, variation of the mean parasite density was statistically significant (P-value <0.01).Higher proportions of malaria cases were found at the end of main rainy season either the beginning of the main dry season at the Hôpital de Mfilou and the CSI «Maman Mboualé»; while, lowest proportions were observed in September and January and in September and March respectively. Higher mean parasite densities were found at the end of rainy seasons with persistence at the beginning of dry seasons. The lowest mean parasite densities were found during dry seasons, with persistence at the beginning of rainy seasons. Fluctuation of the multiplicity of infection throughout the year was observed without significance between seasons.ConclusionThe current study suggests that malaria transmission is still variable between the north and south parts of Brazzaville. Seasonal fluctuations of malaria cases and mean parasite densities were observed with some extension to different seasons. Thus, both meteorological and entomological studies are needed to update the season’s periods as well as malaria transmission intensity in Brazzaville.

Diet of an Assemblage of Four Species of Turtles (Podocnemis) in the Rio Uatumã, Amazonas, Brazil

The structure and functioning of freshwater turtle communities remain understudied topics, especially in tropical regions where biodiversity is higher. The objective of our study was to compare the diets of Podocnemis erythrocephala ,P. expansa, P. sextuberculata, and P. unifilis living in syntopy in Amazonas, Brazil. We tested for qualitative and quantitative variations in the way different species used the same available food resources. We collected fresh stomach flushings from all turtles captured in trammel nets in three lakes in 2012. Sampling was conducted in the four distinct tropical seasons: beginning of rainy season (rising water), peak of rainy season (rapidly rising water), end of rainy season (highest flooded forest water level), and dry season (when water levels were receding). We tested the hypothesis that different food items are available in different quantities at different times of the year due to the seasonality of fruiting trees and other plants in response to the wet and dry conditions. We examined whether food items consumed were related to turtle body size and if there was feeding niche overlap among species. Podocnemis sextuberculata consumed the least amount of food by volume, while P. expansa consumed the highest diversity of food items. All four species are primarily herbivorous, and their diets were composed mainly of fruits and seeds (85.4% mean proportion by volume). Genipa americana (Rubiaceae) was most important in the diet of all species, except in P. sextuberculata. We found some evidence of seasonal differences in the consumption of some plant species. Body size did not influence qualitative (diversity of food items eaten) or quantitative variation of food items (volume), except in P. erythrocephala for which we detected a significant linear relationship between carapace length and the volume of stomach contents. The highest food niche overlap was between P. expansa and P. unifilis, and the lowest niche overlap was between P. erythrocephala and P. sextuberculata. Turtles tended to partition food resources more in areas that had more species feeding in syntopy than in areas with fewer syntopic species.

Comparison between SWAT and SWAT+ for simulating streamflow in a paddy-field-dominated basin, northeast Thailand

The performance of the well-known Soil and Water Assessment Tool (SWAT) and the new SWAT+ for streamflow simulation in a paddy- field-dominated basin was compared. The Lam Sioa River Basin, northeast Thailand (drainage area of 3,394 km2) was selected. The data inputs consisted of DEM, land use, soil, and climate (rainfall, temperature, sunshine hour, wind speed and humidity). The model parameters used the default values from SWAT database and daily simulation was conducted from 2005 to 2017. The division of sub-basins into “landscape units” is one of new features of SWAT+. The total number of HRUs defined from SWAT+ were higher than those from SWAT because the sub-basins derived from SWAT+ contained two landscape units (floodplain and upslope). With the default model parameters, the model performance indicators were found below the satisfactory rating. Both models simulated relatively high streamflow at the beginning of rainy season, while the observed streamflow was still not occurred. In paddy field, rainfall excess become ponding water, not surface runoff. The appropriate representation of paddy field in SWAT model should be further investigated.

Maize yield in a dryland area as affected by rainfall variability

This study aimed to report maize yield in a dryland area of North Lombok as affected by rainfall variability. A three-year study was conducted during a period of maize growing season (December to April) in 2015/2016, 2016/2017 and 2017/2018 in Gumantar village, North Lombok. Daily rainfall data was collected from a rain gauge installed in one of maize farmers’ land. Estimation of drain upper limit and crop lower limit was done based on gravimetric method. Hand-held core kits were used to collect soil samples at 0-15cm, 15-30cm, 30-60cm depth at sowing, fast vegetative growth stage (35 days after sowing=DAS), grain filling stage (85 DAS), and at harvest. Maize yield data were collected from 20 farmers that all grew maize as main crop and legume crop (ground nut or mung bean) as secondary crop. There was great rainfall variability in term of the beginning of rainy season, volume and distribution of the rain as well as the occurrence of dry-spell period resulted in great maize yield variability. The highest maize yield recorded was 8.4 ton/ha and the lowest was 0.6 ton/ha. Growing legume crop in addition to maize can be a good practice in dryland area to avoid total yield loss.

Edaphic and climatic control of macaúba palm seed bank dynamics

The control of soil seed bank (SSB) dynamics is crucial to the ecologies of plant populations of many species, but has been little studied in tropical environments. The objectives of this work were to characterize the SSB of Acrocomia aculeata, an important neotropical oleaginous palm, and to define the influence of edaphic and climatic factors on its dynamics. Exposed and buried diaspores were collected in five areas of the Cerrado biome in central Brazil. Evaluations of the diaspores, young plants, and in vitro embryo cultures defined 26 indicators of SSB dynamics that were correlated with 19 physical-chemical attributes of the soil. Seedlings emergence was studied under greenhouse conditions during five years and the thermal control of germination was evaluated experimentally. A. aculeata forms persistent SSBs, with P being the main edaphic factor associated with seed input. High levels of Al and clay (associated with insect predation), organic matter (fungal contamination), and sand (bacterial contamination) contributed to negative outputs (embryo death). The maintenance of intact SSB embryos, however, is independent of edaphic factors. Wide thermal amplitudes in the winter associated with high temperatures in the spring promote overcoming dormancy and favor positive SSB outputs as well as the synchronization of seedling emergence at the beginning of rainy season. The high productivity of A. aculeata and its ability to maintain viable but dormant embryos in the soil contribute to controlling SSB dynamics, reproductive success, and its wide distribution.

Waterbird Community in A Plantation Forest of An Industrial Area

Waterbird mostly were found in natural wetlands, nesting on mangrove trees. An unusual case was found in a human-made (plantation) forest in an automotive company within an industrial area. The objective of the research was to reveal the species and number of waterbirds that utilized the non-mangrove plantation forest and to record the number of nests and the nest tree preference. Waterbird census was conducted in June and July 2017 (beginning of rainy season) by direct total count of all individuals in the late afternoon (4-6pm). Waterbirds were able to use non-mangrove, plantation forest to roost and nest. On average, there were 4,482 individual resident waterbirds in the study area, consisted of 6 species and occupying 1.77 ha of semi-wetland area (inundated during rainy season), with an average roosting density of 9.4 nests/100m2. The dominant waterbird species were Intermediate Egret (30%), Little Egret (20%), and Black-crowned Night Heron (25%). Other observed species were Cattle Egret (15%), Javan Pond-Heron (5%), and Great Egret (5%). Breeding season was in progress and there were 535 active nests. Although the percentage of nests laid on M. leucadendra trees (49.9%) was similar to A. mangium (47.3%), statistical test suggested that M. leucadendra were highly preferred for nesting trees.

Capillary Shock Phenomenon of Groundwater at the Beginning of Rainy Season

This study aims to determine the causes of decreased water level phenomenon that occurred in the early period of the rainy season. This phenomenon became anti-logic because when the rainwater has entered the soil surface layer, instead of groundwater in the saturated layer decreased (decline). This study is experimental field research conducted in Takalar. This research found that the phenomenon of decreased water level in the early period of the rainy season triggered by increasing of capillary pressure due to shrinking pore diameter after water began to infiltrate into the surface soil layer, i.e., the layer of the vadose zone. Increasing of capillary pressure caused the attraction of groundwater in the saturated zone to the vertical direction, so that the groundwater level has decreased significantly. Therefore, this phenomenon was called by the researcher as “capillary shock phenomenon. (2) The lowest groundwater level did not occur in the climax period of the dry season, but it happened in the early period of the rainy season. The phenomenon that took place during the climax of the dry season was the capillary pressure conditions in the lowest layer of the soil because soil pore diameter reached maximum conditions due to the high evaporation process. Groundwater pumping did not solely cause saltwater intrusion into fresh groundwater zone, but it also could be caused by groundwater decrease for each early period of the rainy season.

Seroprevalence of Filovirus Infection of Rousettus aegyptiacus Bats in Zambia.

Bats are suspected to play important roles in the ecology of filoviruses, including ebolaviruses and marburgviruses. A cave-dwelling fruit bat, Rousettus aegyptiacus, has been shown to be a reservoir of marburgviruses. Using an enzyme-linked immunosorbent assay with the viral glycoprotein antigen, we detected immunoglobulin G antibodies specific to multiple filoviruses in 158 of 290 serum samples of R aegyptiacus bats captured in Zambia during the years 2014-2017. In particular, 43.8% of the bats were seropositive to marburgvirus, supporting the notion that this bat species continuously maintains marburgviruses as a reservoir. Of note, distinct peaks of seropositive rates were repeatedly observed at the beginning of rainy seasons, suggesting seasonality of the presence of newly infected individuals in this bat population. These data highlight the need for continued monitoring of filovirus infection in this bat species even in countries where filovirus diseases have not been reported.

Spatio-Temporal Factors Related to Dengue Hemorrhagic Fever in Makassar City, 2010–2014

Dengue Hemorrhagic Fever (DHF) is an infectious disease caused by the dengue virus is still a public health problem all over the tropics and sub-tropics in the world because it happens every year with a case that is always high. This study aims to describe the spatio-temporal pattern of dengue hemorrhagic fever (DHF) cases in Makassar city in 2010 to 2014, and to analyze the correlation between DHF cases and rainfall rate, larve-free rate, and population density in Makassar city. The research used an ecology study design. The samples, using a total sampling method, were people suffering from DHF (microscopic confirmed) listed in the monthly report of DHF cases in Makassar Health Office from 2010 to 2014. The total number of was 757. This research was conducted from September to November 2015. The data were analyzed spatially (with Moran index), temporally (using graphs), and statistically (using Spearman-rho correlation test); and were processed using ArcGIS 10.3 and IBM SPSS version 20 programs. The results show that the spatial pattern of DHF cases in Makassar city shows a clustered pattern (Moran index = 0.043259).The temporal tendency shows an increase at the beginning of rainy season (January to July) and a decrease at the end of the year after the rainy season (August to December). Based on the statistical test, there is a significant correlation between rainfall rate and DHF incidence (p=0.000 < 0.05). However, there is no significant correlation between DHF cases and larva-free rate (p=0.502 < 0.05); and between DHF cases and population density (p=0.440 < 0.05).

Biomassa e sazonalidade das raízes finas em savanas da Amazônia Oriental

Este trabalho objetivou comparar a biomassa de raízes finas em diferentes fisionomias e avaliar a influência da sazonalidade sobre a massa de raízes finas em savanas amazônicas localizadas no Amapá e Pará. Amostras de solos foram coletadas em cinco profundidades, de 10 em 10 cm, em três pontos no Cerrado sensu stricto, quatro no Campo Cerrado e dois no Campo Limpo, com 4 repetições em cada posição. A influência da sazonalidade foi verificada apenas no Campo Cerrado, em abril (pico das chuvas), julho (final das chuvas) e outubro (pico da seca) de 2010 e em janeiro de 2011 (inicio das chuvas). As fisionomias foram diferenciadas pela massa de raízes, quando analisadas nas diferentes classes diamétricas de raízes e nas diferentes profundidades. A maior massa de raízes finas ocorreu no pico da estação seca. Esses resultados sugerem estratégias diferentes das fisionomias na alocação das raízes mais finas em diferentes profundidas do solo e na dinâmica das raízes para aumentar o potencial de absorção durante a seca.

Dispersal strategies in the highly polygynous ant Crematogaster (Orthocrema) pygmaea Forel (Formicidae: Myrmicinae).

In ants, dispersal strategies and morphology of female sexuals are generally linked to the mode of colony founding. In species using long-range dispersal tactics, queen/worker dimorphism is generally high and young queens are able to initiate new colonies by themselves, using their metabolic reserves. By contrast, in species using short-range dispersal strategies, queen/worker dimorphism is generally low and, due to their limited metabolic reserves, queens have lost the capacity to raise their brood alone and to found their colony independently. Moreover, polygyny is also often associated with short-range dispersal strategies, although the relationship between the number of queens and the dispersal strategy in ants is not clear-cut. Here, dispersal strategies were investigated in C. pygmaea, a highly polygynous and polydomous ant species from northeastern Brazil. Field observations and laboratory experiments show that this ant exhibits a suite of traits that are more commonly associated with long-range dispersal and independent colony foundation: functional wings in both males and females, high queen/worker dimorphism, strong weight loss in mature queens, nuptial flights and, in the lab, ability of young queens to found new colonies in haplometrotic conditions. On the other hand, this species shows a high degree of polygyny with a strong seasonal component, and, at least under laboratory conditions, mature queens seem able to develop propagules if they are accompanied by at least 10 workers. These features strongly suggest that (1) some of the gynes do not engage in a long-range dispersal but become new queens in their mother colony and (2) that budding events are possible in this species. We therefore speculate that C. pygmaea has a dual dispersal strategy probably related to environmental conditions: some gynes engage in long-range dispersal followed by independent colony foundation at the beginning of rainy season, while others mate in the parental colony and are re-adopted leading to high polygyny. During the rainy season, budding events can lead to colony extension and increased polydomy. Polydomy is commonly thought to improve resource discovery and exploitation through decentralized foraging behavior, a significant advantage during the rainy season when food ressources (mainly floral/extrafloral nectaries and hemipteran honeydew) are more abundant and when colony needs for food supplies are highest.

Breeding biology of Pale-breasted Thrush Turdus leucomelas (Turdidae) in the north of Atlantic Forest, Brazil

Reproduction is a key process in the life of organisms and represents high-energy cost to the parents, and often a tradeoff between survival and reproductive success. The breeding biology is an important aspect to be studied, which has inspired theories about bird life history evolution, such as the latitudinal gradient in the clutch size related to different survival rates between the temperate and tropical regions. To contribute with the knowledge of breeding ecology of tropical birds we monitored two reproductive periods of the Pale-breasted Thrush Turdus leucomelas in the northeastern Brazil. The breeding period in the studied area occurred from December through April. We found the nests mainly on Facheiro cactus (Cactaceae) at 1.43 ± 0.35 m above the ground. They were composed by roots, mosses, fungus mycelium, leaves, twigs, and a mix of fragmented vegetal material with soil and sand at the base. We found clutch sizes of three (n = 9), two (n = 3) and one (n = 1) eggs. The eggs (n = 21) had mass of 5.1 ± 0.9 g and measured 26.6 ± 1.3 mm by 19.5 ± 0.5 mm. We observed 12 days of incubation and 14 days of nestling period. The Mayfield nest success in 2013 was 7.3% and in 2014 it was 4.5%, lower during the nestling period than during the incubation in both years. Our results show that T. leucomelas breeds in the area in the beginning of rainy season, when the frequency of occurrence of the migrant Turdus amaurochalinus is low. In addition, the low nest success observed may be a consequence of the localization of the studied area in the periphery of the species range, where limited resources probably result in reduced fitness.

Population and Diversity of Soil and Leaf Litter Mesofauna in Arable Soils at The Agriculture Experimental Field of University of Lampung

This research was conducted to study the population and diversity of soil and leaf litter mesofauna in arable soils under different types of vegetation and slope at the Agriculture Experimental Field (AEF) of University of Lampung. This study was designed to use the survey method. The soil and leaf litter samples were taken from different vegetation and slope classes. Observational variables included population and diversity index of soil mesofauna (H’), soil temperature, soil moisture content, soil pH, soil organic-C, soil total-N, and soil C/N ratio. The data of population distribution were presented in a boxplot diagram and the correlation between soil properties and mesofauna population or mesofauna diversity index were presented. The results showed that the most abundant soil mesofauna was observed in the plots with sugarcane vegetation, either sampled at the end of dry season (November 2015) or at the beginning of rainy season (April 2016). However, the highest number of leaf litter mesofauna was found in the plot with cassava vegetation. This result suggests that the cassava leaf litter most likely became the preferred substrate for mesofauna. In all treatments, the value of mesofauna diversity index (H‘) was categorized as low according to the Shannon-Weaver index. Two dominant orders frequently found in almost all vegetation types were Acarina and Collembola. The results of correlation analysis indicated that only soil pH sampled on November 2015 was positively correlated with the mesofauna population (range of pH 5.0 to 6.6). Soil moisture content sampled on November 2015 and soil C/N ratio sampled on April 2016 were positively correlated with the diversity index of soil mesofauna, respectively. Soil total-N sampled on November 2015 was negatively correlated with the soil mesofauna diversity index. The increase of leaf litter biomass appeared to promote the increase of the leaf litter mesofauna population, but not the diversity index.Keywords: diversity index, leaf litter, soil mesofauna, vegetation