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Science has brought about revolutionary changes in every aspect of life. Its impact is visible everywhere and in every practice of our existence. Thus, science education is a valuable resource in this world. If students have intrinsic motivation, they are active, curious, interested and eager to engage in learning process and the intrinsically motivated behaviors help them acquire knowledge and experience in science. Moreover, educational aspirations and career aspirations are enhanced through better science education. Thus, the present study aimed to investigate the relations of secondary students’ intrinsic motivation and aspirations with their achievement in science. This is a mixed methods study and sample consisted of 2384 students in Grade 8 and Grade 9. Hence, an intervention was implemented to explore students’ intrinsic motivation, aspirations using suitable teaching methodologies and strategies. The results reveal that, there were strong positive relationships of students’ intrinsic motivation and aspirations with their achievement (r2 = .691; .687 respectively) in the experimental group. However, there were very low positive relationship of students’ intrinsic motivation and aspirations with their achievement (r2 = .012; .006 respectively) in the control group. Further, there were significant differences of students’ intrinsic motivation, aspirations and achievement before and after the intervention in the experimental group; t= 48.513 (1132) p=.000; t=53.689 (1132) p=.000; t=65.939 (1132) p=.000 respectively. However, there were no such significant differences of the above aspects before and after the intervention in the control group; t=-.989 (1250) p=.323; t=1.575 (1250) p=.116; t= .968(1250) p= .333 respectively. The findings of the study provided comprehensive understanding of the above relations, develop suitable teaching and learning methodologies and inform the practice in science education. more...

Science is a critical area as it focuses on meeting basic human needs by laying the necessary foundation in everybody in diverse fields. Thus, science impacts everybody in the world and science education demonstrate utmost important. If students have intrinsic motivation, they are well engaged, enquiring, attentive and willing to participate in learning process and the intrinsically motivated behaviors help them acquire knowledge and experience regarding science. Educational aspirations, career aspirations and self-concept promote for better science education. Thus, the present study aimed to address the relations of secondary students’ intrinsic motivation and aspiration with their self-concept in science. This is a mixed methods study and sample comprised 2384 students in Grade 8 and Grade 9. In this study, an intervention was implemented to explore students’ intrinsic motivation, aspirations and self-concept using appropriate teaching methodologies and strategies; results reveal that, there were strong positive relationships of students’ intrinsic motivation and aspirations with their self-concept (r2= .934;.926 respectively) in the experimental group. However, there were very low positive relationships of students’ intrinsic motivation and aspirations with their self-concept (r2 = .093; .058 respectively) in the control group. Further, there were significant differences of students’ intrinsic motivation, aspirations and self-concept before and after the intervention in the experimental group; t=51.926(1232) p=.000; t= 48.513(1232) p=.000; t= 53.689(1232) p=.000 respectively. There was no such significant difference of the above, before and after the intervention in the control group; t=-.5(1150) p=.323; t=-.989(1150) p=.116; t= 1.572 (1150), p=.617 respectively. The findings of the study provided greater understanding of the above relations, develop suitable teaching and learning methodologies and inform the practice of science education. more...

Microbial biofilms developed in-vitro and applied to agroecosystems are reported to restore their soil-plant-microbial relationships by supplying a mixture of diverse biochemicals that reinstate network interactions. Here we hypothesize that the same method can also be used to reinstate unhealthy human body ecosystem caused by altered gut microbiota due to modern lifestyle and dietary patterns. In the present study, we tested biochemicals exuded by a developed fungal-bacterial biofilm (BFEx) on the growth and development of five test gut microbes in a simulated gut environment with eight different dietary patterns. Live microbial cell concentrations of the cultures were analyzed after 24 and 48 hours of inoculation using a bacterial viability kit. In addition, BFEx was tested for cytotoxic activity using brine shrimp lethality assay. Results revealed that the live microbial cell concentrations of the mixed cultures increased while they decreased in the monocultures with the application of BFEx in all dietary patterns. The BFEx promoted the growth and possibly dormancy-breaking of the tested gut microbes. However, it seems that there is a need of an interaction of diverse microbes, if a beneficial outcome from the BFEx is to be achieved. Further, the BFEx showed no toxicity to brine shrimp nauplii, instead it supported for their survival for a while by supplying food sources. In conclusion, this biofilm-based method is a better solution than diet-based interventions for achieving healthy gut microbiota because the former is user-friendly and preserves food-choice-freedom of people, unlike the latter. more...

The cultivation of cash crops in the understorey of tropical forests is an ancient practice, but the effects of cultivation on forest ecosystem processes are poorly understood. We assessed the effects of planting the high-value spice crop cardamom ( Elettaria cardamomum ) on forest structure, tree species composition, and soil properties in the montane forests of the Knuckles Forest Reserve in central Sri Lanka, where cardamom cultivation has been banned since 1985 because of the high conservation value of this site. Vegetation and soil were sampled in forest under-planted with cardamom and adjacent natural forests without planted cardamom. The densities of woody plants (⩾5 cm dbh), saplings ( Macaranga sp. increased in abundance in cardamom plantations, and this contributed to the emergence of a difference in species composition between cardamom plantations and adjacent natural forests. Species richness of trees ⩾5 cm dbh per plot was higher in natural forests than cardamom plantations, while species diversity was higher in cardamom plantations. The concentration of total N in top-soil was higher in natural forests, while concentrations of total P and exchangeable K were higher in the cardamom plantations. We conclude that cardamom cultivation results in a net loss of tree stems through weeding and opening of the canopy to promote cardamom production. The higher concentrations of total P and exchangeable K in the soil of cardamom plantations may be associated with the application of fertilizer, while total N concentration may have been higher in the natural forests because residual uncultivated forest occurs at a slightly higher elevation than the majority of cardamom plantations and/or because of elevated denitrification rates in the cardamom plantation. Since cardamom cultivation has affected forest structure and soil properties, management interventions may be required to mitigate these effects in high conservation value forests where cardamom cultivation has been banned. more...

The density of colonising tree seedlings is often very low in degraded human-induced tropical grasslands. To investigate the mechanisms that constrain seedling establishment in grasslands on former tea plantations in Sri Lanka we planted seedlings of the native tree species Dimocarpus longan Lour., Macaranga indica Wight, Symplocos cochinchinensis (Lour.) S. Moore and Syzygium spathulatum Thw. and examined effects of vertebrate herbivory, and above- and below-ground competition exerted by the grass sward on seedling growth and survival over 28 months. Seedlings of the same species were also planted in remnant patches of lower montane rain forest to determine the effects of habitat on seedling growth and survival. Less than 40% of seedlings survived to 28 months post-transplantation. The highest survival was recorded for Symplocos cochinchinensis in both grassland and forest, while Macaranga indica seedlings had the highest relative growth rate of height (RGRh) in both habitats. Root competition reduced survival of Macaranga indica and the RGR h of Macaranga indica , Symplocos cochinchinensis and Syzygium spathulatum in the grassland, while above-ground competition and exclusion of vertebrate herbivores had no effects on seedling establishment. These results suggest that Symplocos cochinchinensis would be suitable for re-establishing forest cover on degraded grasslands, although Macaranga indica would be more likely to catalyse succession because it possesses animal-dispersed fruit. Measures that overcome or restrict the effects of root competition from grasses would enhance tree seedling growth and survival more than manipulation of the light environment or protection from vertebrate herbivores. more...

Summary 1. Colonization by woody plants is often very slow or absent on grasslands occupying degraded land in the tropics. Seed dispersal limitation is widely reported, but the constraints to forest succession imposed by barriers to seedling establishment are poorly understood. We tested the hypotheses that seedling emergence of woody plants is limited by interactions of anthropogenic fire, vertebrate herbivory and competition with the dominant grass sward in human-induced montane grasslands in Sri Lanka. 2. Seedling emergence was determined fortnightly for 18 months in response to experimental manipulation of fire regimes, access by vertebrate herbivores and competition from the dominant grass canopy at the forest/grassland edge and at 10, 20 and 40 m from the edge into four blocks of grassland. Seedling emergence was also monitored in the absence of any experimental manipulation at 10, 20 and 40 m into adjacent blocks of lower montane rainforest. 3. Emergence of seedlings of woody plants was much lower in the grassland (mean more...

It is well known that invasive species alter vegetation structure and composition, but most ofthe evidence to support this claim come from natural ecosystems. In many instances, thesestudies reported negative consequences on these natural habitats. Within last few years, thehighly degraded grasslands at the Knuckles Conservation Area (KCA) have rapidly invadedby Austroeupatorium inulifolium, a notorious invasive species. The present study was aimedat investigating the impacts of Austroeupatorium on grassland communities, and also to seeany positive role in forest expansion process towards these invasive grasslands by borderingforest remnants. A complete vegetation sampling was carried out in 3 grassland communities having differentlevels of invasion; grasslands densely-invaded with Austroeupatorium (HIG), and lessdenselyinvaded (LIG) and the forest-grassland edge (FGE). For each grassland community,nine randomly placed 4 m2 quadrates were used to enumerate the vegetation. Anothersampling was carried out using two forest-grassland edge (FGE) communities; forest remnantbordered by LIG (FGE- LIG) and forest remnant bordered by HIG (FGE- HIG). At each site,5 linear quadrates (3 m x 12 m) were placed parallel to the FGE at different distances; 0(edge), 5 and 10 m away from the edge towards the grassland and towards the forest interior.Six such transects were sampled for each FGE category. A total of 30 species have been identified belonging to 20 families in HIG while 21 species(belonged to 14 families) and 14 species (belonged to 9 families) were identified from LIGand FGE respectively. Tree saplings (4 species) were recorded only in HIG. The two edgehabitats showed somewhat different vegetation composition. Of the 182 and 430 individualsof tree saplings encountered at FGE-LIG and FGE-HIG respectively, majority of them werefound in quadrates laid inside the forest (76 and 88% respectively). Abundance and richnessof tree saplings were significantly higher at 10 m towards the forest interior bordered by HIGthan that of LIG. Present results suggested that Austroeupatorium invasion has a facilitative effect on treeseedling establishment probably through enhanced shading effect and improved edaphicconditions. The results also suggest that Austroeupatorium invasion has the potential tochange the community structure in forest-grassland edges which eventually influence thevegetation community in the forest interior, at least up to 10 m. The facilitative effect ofAustroeupatorium invasion on the forest tree establishment needs further studies to verify itslong-term effect on these grasslands. more...

Invasion of alien species into new habitats poses serious threats to their vegetation andecosystem processes. Austroeupatorium inulifolium, an invasive species, has been rapidlyinvading degraded grasslands dominated by Cymbopogon nardus, another invasive, in theKnuckles Conservation Area (KCA). Invasive plants with rapid growth rates and elevatedleaf nutrient concentrations could alter decomposition process and nutrient release patterns.This study was aimed at studying the litter quality, decay rates and nutrient release patterns ofAustroeupatorium and Cymbopogon. In situ litterbag experiment was conducted in less andhighly invaded grasslands at KCA. Surface litter and standing litter (above-ground) also havebeen quantified to assess the contribution of C3 and C4 plants to soil nutrient pool. Litterbags (n=40) were prepared with air-dried litter samples of Austroeupatorium andCymbopogon and were distributed in highly-invaded (HIG) and less invaded (LIG) sites (byAustroeupatorium). Litterbags were collected at different time intervals and chemicallyanalysed. The decomposition rate was calculated using loss of litter biomass. The surfacelitter was estimated using randomly placed quadrates (0.0625 cm2). Standing litter biomasswas quantified by clipping quadrates (0.25 m2) to the ground level. Contributions to abovegroundlitterfall by C3 and C4 plants were assessed. The results were statistically analysedand compared using Minitab 14.0. Higher mass loss was observed with Austroeupatorium litter than that of Cymbopogon inboth less and highly invaded habitats. Austrosupatorium litter quality (in terms of N and P) ishigher than that of Cymbopogon. Leaf litter of Austroeupatorium showed significantly lowerC:N and C:P ratios compared to Cymbopogon. Nitrogen and phosphorus release patternsduring decomposition found to be slow in both Austroeupatorium and Cymbopogonirrespective of their habitats. Austroeupatorium showed relatively higher decomposition ratethroughout the study period compared to Cymbopogon. The surface litter and standing litterbiomasses were significantly higher in HIG compared to LIG. In both habitats, C3 plantscontributed more to the standing litter biomass than that of C4 plants. Austroeupatoriumplants contributed more to the total C3 biomass in both LIG and HIG. The present results suggest that due to higher quality and decomposition rates ofAustroeupatorium litter, the invasion may leads to changes in the soil nutrient pools and alsotheir cycling processes. Long-term soil studies need to be carried out in order to investigatethese findings further. more...