Rangelands occupy 51% of the terrestrial land surface, 23% total land of Nepal. It contains about 36% of the world＇s total carbon in above and belowground biomass. Rangelands can aid in the mitigation of rising atmospheric carbon dioxide concentrations via carbon storage in biomass and soil organic matter. A study on carbon stock on soil and vegetation at various altitudinal gradients in Milke-Jaljale rangeland area of Eastern Nepal was made. The study was carried out at three altitudinal gradients （above sea levels） Milke （3,000 m）, Gorujure （3,500 m） and Jaljale （4,000 m）. This method required establishing a transect line. Sample points were located by pacing the appropriate distances from the point of origin at a transect line. To determine distribution and quantity of plant carbon and soil organic carbon （SOC）, 45 sample points were established and 15 points were sampled from each study site. Total soil carbon was estimated as follows： 17.65 t/ha at Milke, 17.27 t/ha at Gorujure and 28.33 t/ha at Jaljale. Similarly, total vegetation carbon was estimated 22.68 t/ha at Milke, 29.79 t/ha at Gorujure and 42.54 t/ha at Jaljale. Highest elevation study site with least external disturbance （Jaljale area） had high storage of carbon in both cases vegetation and soil. 相似文献
The performance of six existing deep learning architectures were compared for the task of detection of mango fruit in images of tree canopies. Images of trees (n?=?1 515) from across five orchards were acquired at night using a 5 Mega-pixel RGB digital camera and 720 W of LED flood lighting in a rig mounted on a farm utility vehicle operating at 6 km/h. The two stage deep learning architectures of Faster R-CNN(VGG) and Faster R-CNN(ZF), and the single stage techniques YOLOv3, YOLOv2, YOLOv2(tiny) and SSD were trained both with original resolution and 512?×?512 pixel versions of 1 300 training tiles, while YOLOv3 was run only with 512?×?512 pixel images, giving a total of eleven models. A new architecture was also developed, based on features of YOLOv3 and YOLOv2(tiny), on the design criteria of accuracy and speed for the current application. This architecture, termed ‘MangoYOLO’, was trained using: (i) the 1 300 tile training set, (ii) the COCO dataset before training on the mango training set, and (iii) a daytime image training set of a previous publication, to create the MangoYOLO models ‘s’, ‘pt’ and ‘bu’, respectively. Average Precision plateaued with use of around 400 training tiles. MangoYOLO(pt) achieved a F1 score of 0.968 and Average Precision of 0.983 on a test set independent of the training set, outperforming other algorithms, with a detection speed of 8 ms per 512?×?512 pixel image tile while using just 833 Mb GPU memory per image (on a NVIDIA GeForce GTX 1070 Ti GPU) used for in-field application. The MangoYOLO model also outperformed other models in processing of full images, requiring just 70 ms per image (2 048?×?2 048 pixels) (i.e., capable of processing?~?14 fps) with use of 4 417 Mb of GPU memory. The model was robust in use with images of other orchards, cultivars and lighting conditions. MangoYOLO(bu) achieved a F1 score of 0.89 on a day-time mango image dataset. With use of a correction factor estimated from the ratio of human count of fruit in images of the two sides of sample trees per orchard and a hand harvest count of all fruit on those trees, MangoYOLO(pt) achieved orchard fruit load estimates of between 4.6 and 15.2% of packhouse fruit counts for the five orchards considered. The labelled images (1 300 training, 130 validation and 300 test) of this study are available for comparative studies.
The need for biodiesel feedstocks growing on non-arable lands is widely recognized. We present results of the synthesis and characterization of new biodiesels we produced from oils of highbush cranberry, dotted horsemint, and American hazelnut growing in Northern Wisconsin. These biodiesels, particularly those derived from highbush cranberry, exhibited remarkably good low-temperature properties, a condition that is crucial for wider usage of any biodiesel in cold climates. We also present the results on determination of the oxidative stability of the above biodiesels and discuss the growing conditions and habitats of the related plants. 相似文献
The national maize improvement program in Nepal regularly receives elite maize (Zea mays L.) genotypes from CIMMYT and other countries and tests them for their performance stability in highly diverse environments.
Studies were conducted on research stations and farmers’ fields at five sites in three years to determine performance stability
of exotic maize genotypes. Replicated on-station and on-farm studies were conducted using 25 and 10 genotypes, respectively,
including a local check and an improved check (Manakamana-3), in 2004–2006. We analyzed grain yield, days to flowering, plant
and ear height, plant population, husk cover, and plant and ear aspect. Stability and genotype superiority for grain yield
was determined using genotype and genotype × environment (GGE) biplot analysis that compares among a set of genotypes with
a reference ‘ideal’ genotype, which has the highest average value of all genotypes and is absolutely stable. Several genotypes
produced significantly higher grain yield than the local check. Four genotypes (‘Across9942 × Across9944’, ‘Open Ended White
Hill Population’, ‘Population 44C10’ and ‘ZM621’), that produced significantly higher grain yield than the improved check,
also had other agronomic traits (days to flowering, plant and ear height, number of ears, resistance to leaf blight, plant
and ear aspect and husk cover tightness) equal to or better than the improved check. GGE-biplot analysis showed that Across9942 × Across9944
and ZM621 were the most superior genotypes in the on-station and on-farm trials, respectively. The findings from this study
provide new information on the stability of the maize genotypes that are also adapted to other regions of the world. Such
information could be useful for maize improvement program for the highlands in Nepal and other similar environments. 相似文献
Eurasian Soil Science - This study provides an estimate of soil organic carbon (SOC) stock, projects future SOC stocks under different climate change scenarios, and considers impacts on topsoil SOC... 相似文献
The relationships between group size, survival, and longevity vary greatly among social species. Depending on demographic and ecological circumstances, there are both positive and negative effects of group size variation on individual survival and longevity. For socially foraging species in particular there may be an optimal group size that predicts maximum individual survival that is directly related to the potential for information transfer, social coordination, and costs of conspecific interference. Our aim was to investigate this central aspect of evolutionary ecology by focusing on a socially foraging bat, Molossus molossus. This species optimizes foraging success by eavesdropping on the echolocation calls of group members to locate ephemeral food patches. We expected to find the highest survival and longest lifespans in small groups as a consequence of a trade-off between benefits of information transfer on ephemeral resources and costs of conspecific interference.
Results
In a mark-recapture study of 14 mixed-sex M. molossus social groups in Gamboa, Panama, spanning several years we found the expected relatively small and intermediate, but stable groups, with a mean size of 9.6 ± 6.7 adults and juveniles. We estimated survival proxies using Cox proportional hazard models and multistate-mark recapture models generated with recapture data as well as automated monitoring of roost entrances in a subset of the groups. Median survival of females was very short with 1.8 years and a maximum estimated longevity of 5.6 years. Contrary to our expectations, we found no relationship between variation in group size and survival, a result similar to few other studies.
Conclusions
Strong selection towards small group size may result from psychoacoustic and cognitive constraints related to acoustic interference in social foraging and the complexity of coordinated flight. The short lifespans were unexpected and may result from life at the energetic edge due to a highly specialized diet. The absence of a relationship between group size and survival may reflect a similar but optimized survival within the selected range of group sizes. We expect the pattern of small group sizes will be consistent in future research on species dependent on social information transfer about ephemeral resources.
