scholarly journals Intra annual seed production and availability of two morphotypes of Brosimum rubescens taubert in forests of the Colombian Amazon

2014 ◽  
Vol 14 (4) ◽  
Author(s):  
Luis Eduardo Rivera ◽  
María Cristina Peãuela ◽  
Flavio Moreno

We assessed the reproductive phenology, production, and availability of seeds for two morphotypes of Brosimum rubescens Taub. (Moraceae), locally known as black palosangre (BP) and white palosangre (WP) during an annual cycle in a 20-ha mega plot located in a primary forest at the El Zafire Biological Station, in the Colombian Amazon. We found that 87% and 41% of potentially reproductive individuals of BP and WP respectively, was fertile and the production of reproductive structures was variable within and between morphotypes. The phenological pattern was seasonal in both morphotypes, characterized by flowering at the end of the dry season and fruiting at the start of the rainy season. BP produced and aborted large amounts of infructescences (approximately 21743), possibly as a response to satiate predators. Relative predation in terms of pre-dispersion of seeds was similar in both morphotypes, with a greater damage generated by a Scolytidae Curculionidae (Coleoptera) and to a lesser degree by frugivorous vertebrates. The number of mature fruits, total seeds, and removed seeds was similar for both morphotypes. Differences in the amount of reproductive structures and in the timing of phenophases between morphotypes decreased the competition and contributed to their coexistence. It seems that in undisturbed forests seed limitation could be more conditioning for WP, while other limitations after fruit and seed production could occur in BP.

2017 ◽  
pp. 67
Author(s):  
Dulce María Figueroa-Castro ◽  
Zenón Cano-Santana ◽  
Edgar Camacho-Castillo

We studied the production of reproductive structures and the reproductive phenology of five Compositae species in a xeric community in Central Mexico: Eupatorium petiolare, Tagetes lunulata, Senecio praecox, Dahlia coccinea and Verbesina virgata. The last three species were studied in two sites with contrasting light conditions. The number of reproductive structures produced by D. coccinea was higher in the open site than in the shaded one. In contrast, S.praecox had a higher production in the shaded site, but V. virgata showed no differences. The reproductive phenology of V. virgata and D. coccinea was different between sites, but it was not happen in S. praecox. The species that flowered during the dry season had a shorter reproductive period (E. petiolare: 2.8 mo; S. praecox: 2.0 mo) than those that flowered during the rainy season or during the late rainy season (D. coccinea: 11.0 mo; T. lunulala: 8.5 mo; V. virgata: 8.5 mo) , which was caused by the high duration of the mature fruit stage in these species.


1992 ◽  
Vol 6 (1) ◽  
pp. 161-168 ◽  
Author(s):  
María T. Moyá

Sex ratios were determined for 15 populations of Marchantia chenopoda L. along Puerto Rico. Sex was determined for twenty randomly selected individuals from each population. A female bias was observed in most populations. A census of reproductive structures of M. chenopoda was performed every two weeks in order to determine phenology. The highest archegoniophore count was observed to occur in January and February; minimum and maximum fertilization distances were 0.7 cm and 65 cm, respectively. Young sporophytes were most frequently observed at the beginning of the rainy season, in April and May. The highest frequency of mature sporophytes occurred during the dry season, in January and February. Capsules opened mostly during the heavy rainy season, from August to November. Protonemata were observed in the periphery of the population. Most young sporophytes aborted at the end of the moderate to heavy rainy season, from June to August. Immature gemmae cups were most frequent at the beginning of the rainy season, in April and May. Mature gemmae cups were observed throughout the rainy season, but were most frequent in September.


2009 ◽  
Vol 25 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Rosario Rojas-Robles ◽  
F. Gary Stiles

Abstract:During a 4-y study of the palm Oenocarpus bataua, 368 reproductive structures on 102 palms were monitored. A reproductive structure required nearly 2 y for successful completion, from bud to ripe fruit. We found correlations with summed rainfall and averaged relative humidity and/or solar radiation for initiation of bud appearance, flowering and fruit maturation over 0–4 mo prior to the events, and another set of correlations over longer periods up to 11–12 mo before. Climatic variables showing short-term correlations (apparently triggering an event) often differed from those showing long-term correlations (which presumably initiated developmental processes culminating in the event itself). A high degree of asynchrony occurred in production of reproductive structures both within and between individual palms even within major reproductive peaks, and there were pronounced differences between individuals in total reproductive effort. Nearly all palms passed 1–3 y with little or no reproduction despite similar environmental conditions between years. We conclude that the supra-annual cycle of this palm is not the result of inadequate environmental cues in some years. There appear to be at least two different types of supra-annual cycles in tropical plants, differing in the relative importance of extrinsic cues vs. intrinsic physiological rhythms and in intrapopulation synchrony.


1998 ◽  
Vol 49 (3) ◽  
pp. 271 ◽  
Author(s):  
Carlos López ◽  
Enrique Ochoa ◽  
Rita Páez ◽  
Solange Theis

Prevalence and substrate specificity of epizoans on crustacean zooplankton were examined during an annual cycle in Tulé Reservoir, a large, shallow and polymictic waterbody in western Venezuela. Epistylis sp., a ciliate protozoan, and Synedra sp., a pennate diatom, were the most frequent epibiont taxa. The prevalence of all epibionts on 1800 individual crustaceans was only 3.3%, and the occurrence of the two epibiotic taxa together on the same substrate zooplankter was low (3.3% of total infested crustaceans). Cyclopoid copepods were preferred as substrate for Epistylis sp. Neither epibiont taxon was found on copepodids or adults of a calanoid. Both epibionts were absent in the early rainy season but appeared in mid rainy season and showed the highest prevalence in the early dry season. During the remainder of the dry season prevalence was low. Epibiont prevalence was not related to presence or absence of zooplankton taxa or water temperature. Differences from temperate epibiont communities are discussed Resumen. A lo largo de un ciclo anual, se estudió la prevalencia y la especificidad al sustrato de los epibiontes de la comunidad de crustáceos planctónicos del Embalse Tulé, un cuerpo de agua somero y polimictico del Occidente de Venezuela. Epistylis sp., un protozoario ciliado, y Synedra sp., una diatomea pennada, fueron los taxones más frecuentes. La prevalencia de ambos epibiontes en conjunto sobre los 1.800 individuos examinados fue de 3,3% y la presencia de ambos epibiontes en el mismo sustrato fue baja (3,3% del total de individuos infestados). Los copépodos ciclopoideos fueron preferidos por Epistylis como sustrato. Ningún epibionte se observó en los copépodos calanoides. Los epibiontes aparecieron a mediados del período de lluvias y alcanzaron su máxima prevalencia al principio del período de sequía. La prevalencia no se encontró relacionada ni con la presencia o ausencia de las especies zooplanctónicas ni con la temperatura del agua. En el presente trabajo se realizan comparaciones con las comunidades epibiónticas de la zona templada y se discuten explicaciones a las diferencias encontradas.


2018 ◽  
Vol 11 (1) ◽  
pp. 2201-2217
Author(s):  
Dr. NDRI Kouadio Julien ◽  
Arnauth M. Guaci ◽  
Thierry Hance ◽  
Joseph G. Yaco ◽  
Jean-Luc D.S. Ahui ◽  
...  

Due to their interaction with many other small Arthropods, Uropodina mites can be considered as good indicators of soil fauna of forest litter. In order, to better understand their distribution and phenology according to forest type four sites from primary forest to plantations were sampled in 2008 in Côte d’Ivoire: 1- the Lamto savannah (6°13' N, 5°02' W), 2- Oumé primary forest (6°31’ N, 5°30’ W), 3- Oumé teak plantation (6°31’ N, 5°30’ W) all situated in the Sudanese domain and finally, 4- the Taï primary forest (5°45’ N, 7°07 W) located in the Guinean domain. After a preliminary study devoted to the efficiency of Berlese Tullgren funnel, the spatiotemporal variation of two Uropodina genera - Afrotrachytes Kontschán, 2006 and Trachyuropoda Berlese, 1888 - was assessed. We hypothesized that the abundance of Uropodina would be higher in primary forest and lower in savannah and monospecific plantation. Whatever the season, we expected that the abundance of Uropodina would decrease with soil depth and would vary along transect. On each site, 15 sampling points were allocated over a 14-m transect with 1m intervals between two consecutive points. For each sampling point, 9 cores (litter, 0-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35 and 35-40 cm) were taken with a steel corer (Ø 3.5 cm). Thus, a total of 1,080 soil cores were collected over two sampling periods from January to March 2008 (dry season) and August to October 2008 (rainy season). Soil physico-chemical parameters were also characterized. Mites were extracted using the Berlese-Tullgren funnels for one week after testing the extraction duration in a preliminary study. The bulbs lighting as soon as the soil cores were placed in Berlese Tullgren gave better results regarding the abundance of extracted mites. The results showed that the abundance of Afrotrachytes sp and Trachyuropoda sp was higher in rainy season, and varied significantly through the sites, whatever the season. The highest abundances of Afrotrachytes sp were observed in Oumé primary forest whereas those of Trachyuropoda sp were recorded in Oumé primary forest, and in Lamto savannah, whatever the season. Apart from the distribution of Trachyuropoda sp in dry season, the abundance of Afrotrachytes sp and Trachyuropoda sp was greater in the topsoil (litter and 0-5 cm) and decreased with soil depth. The abundances of Afrotrachytes sp and Trachyuropoda sp did not follow a normal distribution along the transects. The season-soil depth interaction affected significantly the abundance of Trachyuropoda sp whereas the bulk density (dry season and rainy season), soil depth (dry season), carbon / nitrogen ratio (dry season) impacted significantly the abundance of Afrotrachytes sp. This first study highlighted the spatiotemporal variation of Uropodina in Côte d’Ivoire. However, taking into account of the different dispersal agents in future studies would help us to better understand their abundance and distribution along different habitats, as well as their role as biological control agents.


2020 ◽  
Vol 14 (4) ◽  
pp. 286-290
Author(s):  
Naiara Silva Menezes Dantas ◽  
Luciene Almeida Siqueira de Vasconcelos ◽  
Pedro de Queiroz Costa Neto ◽  
Felipe Faccini dos Santos

Egg quality has been widely studied, mainly because defects in quality can pose risks to public health, as well as economic losses.Nevertheless, studies about fungiin eggsare scarce. The objective was to compare the fungal microbiota from washed and unwashed eggs in the rainy season and dry season of the year. This exploratory research consisted in the analysis of large size white table eggs acquired from 48 different lots. Two manufacturers were sampled considering the main characteristic of washed or unwashed eggs. From each lot, a 30-egg pack were purchased and six of those eggs were used for mycological analyzes. The eggs were analyzed externally with 0.1% peptone salt solution wash of the eggshells and internally with aliquots being sampled from a pool made from the six eggs content. Samples were inoculated in Potato Dextrose Agar and isolated colonies were passed to test tubes. When sporulated, the isolates were subjected to decimal dilutions using 0.1% Tween 80 to dissociate the conidia. Microcultures were carried out for optical microscopy observation of the reproductive structures of fungi, stained with lactophenol. Aspergillusspp. was the most frequently isolated fungi isolated, with A. nigerand A. flavuspredominant in the dry season, while A. fumigatusand A. terreusin the rainy season. Low numbers of fungi were identified from egg shells, with a higher amount from unwashed eggs. The seasondid not influence the numberof fungi in eggs, despite having influenced the fungal diversity.


2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Sardjito Eko Windarso dkk

The increasing of malaria cases in recent years at Kecamatan Kalibawang has been suspected correspond with the conversion of farming land-use which initiated in 1993. Four years after the natural vegetation in this area were changed become cocoa and coffee commercial farming estates, the number of malaria cases in 1997 rose more than six times, and in 2000 it reached 6085. This study were aimed to observe whether there were any differences in density and diversity of Anopheles as malaria vector between the cocoa and mix farming during dry and rainy seasons. The results of the study are useful for considering the appropriate methods, times and places for mosquito vector controlling. The study activities comprised of collecting Anopheles as well as identifying the species to determine the density and diversity of the malaria vector. Both activities were held four weeks in dry season and four weeks in rainy season. The mea-surement of physical factors such as temperature, humidity and rainfall were also conducted to support the study results. Four dusuns which meet the criteria and had the highest malaria cases were selected as study location. Descriptively, the results shows that the number of collected Anopheles in cocoa farming were higher compared with those in mix horticultural farming; and the number of Anopheles species identifi ed in cocoa farming were also more varied than those in the mix horticultural farming.Key words: bionomik vektor malaria, anopheles,


Author(s):  
Titis Apdini ◽  
Windi Al Zahra ◽  
Simon J. Oosting ◽  
Imke J. M. de Boer ◽  
Marion de Vries ◽  
...  

Abstract Purpose Life cycle assessment studies on smallholder farms in tropical regions generally use data that is collected at one moment in time, which could hamper assessment of the exact situation. We assessed seasonal differences in greenhouse gas emissions (GHGEs) from Indonesian dairy farms by means of longitudinal observations and evaluated the implications of number of farm visits on the variance of the estimated GHGE per kg milk (GHGEI) for a single farm, and the population mean. Methods An LCA study was done on 32 smallholder dairy farms in the Lembang district area, West Java, Indonesia. Farm visits (FVs) were performed every 2 months throughout 1 year: FV1–FV3 (rainy season) and FV4–FV6 (dry season). GHGEs were assessed for all processes up to the farm-gate, including upstream processes (production and transportation of feed, fertiliser, fuel and electricity) and on-farm processes (keeping animals, manure management and forage cultivation). We compared means of GHGE per unit of fat-and-protein-corrected milk (FPCM) produced in the rainy and the dry season. We evaluated the implication of number of farm visits on the variance of the estimated GHGEI, and on the variance of GHGE from different processes. Results and discussion GHGEI was higher in the rainy (1.32 kg CO2-eq kg−1 FPCM) than in the dry (0.91 kg CO2-eq kg−1 FPCM) season (P < 0.05). The between farm variance was 0.025 kg CO2-eq kg−1 FPCM in both seasons. The within farm variance in the estimate for the single farm mean decreased from 0.69 (1 visit) to 0.027 (26 visits) kg CO2-eq kg−1 FPCM (rainy season), and from 0.32 to 0.012 kg CO2-eq kg−1 FPCM (dry season). The within farm variance in the estimate for the population mean was 0.02 (rainy) and 0.01 (dry) kg CO2-eq kg−1 FPCM (1 visit), and decreased with an increase in farm visits. Forage cultivation was the main source of between farm variance, enteric fermentation the main source of within farm variance. Conclusions The estimated GHGEI was significantly higher in the rainy than in the dry season. The main contribution to variability in GHGEI is due to variation between observations from visits to the same farm. This source of variability can be reduced by increasing the number of visits per farm. Estimates for variation within and between farms enable a more informed decision about the data collection procedure.


2021 ◽  
Vol 13 (2) ◽  
pp. 741
Author(s):  
Wirat Krasachat ◽  
Suthathip Yaisawarng

To overcome the challenging food safety and security problem, in 2003, the Thai government initiated ‘Good Agricultural Practices’ (GAP) technology. This paper used a sample of 107 small chili farms from the Chiyaphoom province for the 2012 crop year, and data envelopment analysis (DEA) meta-frontier directional distance function technique to answer two questions: (1) Are GAP-adopting farms, on average, more efficient than conventional farms? (2) Does access to GAP technology affect farmers’ decisions to adopt GAP technology? We also developed an ‘indirect’ approach to reduce the potential sample selection bias for small samples. For the dry-season subsample, GAP farms were more technically efficient when compared with non-GAP farms. These dry-season non-GAP farms may not adopt the GAP method because they have limited access to GAP technology. For the rainy-season subsample, on average, GAP farms were more efficient than non-GAP farms at the 5% level. Access to the GAP technology is not a possible reason for non-GAP rainy season farms to not adopt the GAP technology. To enable sustainable development, government agencies and nongovernmental organizations (NGOs) must develop and implement appropriate educational and training workshops to promote and assist GAP technology adoption for chili farms in Thailand.


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