Effect of defoliation treatment on Mimosa pigra L. seedling survivability and resilience

Current advancements in the study of the theoretical basis of species interactions are helping scientists understand the basic parameters governing the dynamics of the interactions between generalist herbivores and their target plants. In practice, however, both inter- and intra-specific interactions between plants (as well as between herbivores and plants) within multispecies systems that are under the influence of interrelated biotic and abiotic variables are difficult to predict. Here, we discuss our findings on the effect of simulated herbivory on Mimosa pigra L. leaves on seedling survivability. In Malaysia, M. pigra, a semi-aquatic invasive plant introduced from the South American region, is already creating an ecological problem, especially in wetland habitats. To better understand the impact of herbivores on the M. pigra population, a simulated experiment of the herbivory effect on Mimosa seedlings was conducted. This experiment combined two treatments of simulated herbivory on the leaves of established Mimosa seedlings, that is, a two-level intensity treatment (50 and 100 % defoliation) and a seven-level frequency treatment (one to seven defoliations). The data suggest that Mimosa is highly resilient against herbivory. This plant was able to compensate for repeated losses, thus suggesting that the introduction of herbivores in an effort to totally eradicate the Mimosa population is unlikely to be successful.     

Transcriptome-wide effects of expansin gene manipulation in etiolated Arabidopsis seedling

Journal of Plant Research - Expansin is a non-enzymatic protein which plays a pivotal role in cell wall loosening by inducing stress relaxation and extension in the plant cell wall. Previous...     

Fatty acid compositional changes during the embryonic development of the swimming crab,Portunus pelagicus (Portunidae: Decapoda)

Abstract

The fatty acid composition, moisture, and total lipid of the eggs from the swimming crab, Portunus pelagicus, at three different embryonic stages (within 24 h, during the eye placode stage and the final heart beat stage), were measured. Results showed that the moisture and lipid content significantly increased and decreased (p < 0.05), respectively, as the stages progressed. The most prevalent fatty acids that were initially deposited included C16:0, C18:1n-9, and C18:0, while the most consumed fatty acids were C22:5n-6, C22:5n-3, and C20:1n-7. Among the major fatty acid groups, polyunsaturated fatty acids (PUFA) and long-chain PUFA (LC-PUFA) were consumed more than saturated fatty acids and significantly more (p < 0.05) than monounsaturated fatty acids (p < 0.05). Meanwhile, n-3 PUFA was deposited in significantly higher amounts (p < 0.05) than n-6 PUFA, but both were consumed at similar amounts at 43.4% and 41.3%, respectively. The relatively low amount of C20:5n-3 and C22:6n-3 consumption may indicate these fatty acids were conserved, while the essential fatty acids C18:3n-3 and C18:3n-6 were consumed at high amounts. These findings may have implications for broodstock nutrition in order to formulate a well-balanced diet.     

Effect of differential forest management on biodiversity in a tropical hill forest of Malaysia and implications for conservation

Forest ownership is considered as vital for sustainable management of forest and its associated biodiversity. The Global Forest Resources Assessment 2015 reported an increasing rate of privately owned forests on a global scale. However, deforestation was found to be very active in privately owned hill forest areas of Malaysia. Three forest reserves and three adjacent private forests from Penang State was purposively chosen as this state has been experiencing a quick and radical changes due to urban expansion over the last three decades. In this study variation in biodiversity were measured using community structure of both vascular plants and avifauna species along selected micro environmental variables. Finally implications for conservation were proposed considering the current state of deforestation in private hill forest (PHF). Plant community and avifauna analysis revealed that government hill forest areas (GHF) were more diverse and healthier than PHF, also rich with higher evenness. Species richness between GHF and PHF showed significant difference in plant species (p < 0.05) but not for avifauna. Avifauna diversity analysis recorded higher abundance of birds in PHF and finally appeared as buffer service provider for avifauna diversity in GHF reserves. But the current rate of deforestation in PHF is 1.4% annually. Thus any alteration to hill forest cover (land development activities) should be banned immediately with intensive care to the PHF through co-management. Moreover human activities inside the GHF should also be controlled to conserve the remnant species of the island as conspicuous disturbance were also found inside GHF.     

Robust Identification of Polyethylene Terephthalate (PET) Plastics through Bayesian Decision

Recycling is one of the most efficient methods for environmental friendly waste management. Among municipal wastes, plastics are the most common material that can be easily recycled and polyethylene terephthalate (PET) is one of its major types. PET material is used in consumer goods packaging such as drinking bottles, toiletry containers, food packaging and many more. Usually, a recycling process is tailored to a specific material for optimal purification and decontamination to obtain high grade recyclable material. The quantity and quality of the sorting process are limited by the capacity of human workers that suffer from fatigue and boredom. Several automated sorting systems have been proposed in the literature that include using chemical, proximity and vision sensors. The main advantages of vision based sensors are its environmentally friendly approach, non-intrusive detection and capability of high throughput. However, the existing methods rely heavily on deterministic approaches that make them less accurate as the variations in PET plastic waste appearance are too high. We proposed a probabilistic approach of modeling the PET material by analyzing the reflection region and its surrounding. Three parameters are modeled by Gaussian and exponential distributions: color, size and distance of the reflection region. The final classification is made through a supervised training method of likelihood ratio test. The main novelty of the proposed method is the probabilistic approach in integrating various PET material signatures that are contaminated by stains under constant lighting changes. The system is evaluated by using four performance metrics: precision, recall, accuracy and error. Our system performed the best in all evaluation metrics compared to the benchmark methods. The system can be further improved by fusing all neighborhood information in decision making and by implementing the system in a graphics processing unit for faster processing speed.     

Rattan (Calamoideae) abundance and above-ground biomass at a primary rainforest of Peninsular Malaysia

Background: Rattans are widespread throughout paleo-tropical forests; however, there is no information on their contribution to above-ground biomass (AGB).

Aims: This study established biomass baseline values for 11 different rattan species in a Malaysian primary forest, and calculated the overall rattan AGB contribution and dynamics during two years.

Methods: All rattan stems in five 100 m × 100 m study plots were counted in 2011 and 2013. Biometric non-invasive measurements were carried out on 11 climbing and non-climbing species and total rattan biomass for both years calculated was compared.

Results: Rattans contributed with 3.1 Mg ha^?1 to the forest AGB. There was no significant change in rattan biomass between the years.

Conclusions: These preliminary results are the first published on the AGB contribution of rattans to Malaysian primary forests. Further studies are required to ascertain values across forest types and over time to reliably estimate the contribution of rattan species to ABG and carbon sequestration.