Cascading effect of source limitation on the granivore-mediated seed dispersal of Korean pine (Pinus koraiensis) in secondary forest ecosystems

Background Granivore-mediated seed dispersal is susceptible to changes in seed availability and silvicultural management, which alters synzoochorous interactions in the antagonism-mutualism continuum and affects the seed dispersal effectiveness (SDE), and eventually, the plant recruitment. We conducted a whole-year study of seed addition to quantify the granivores-Korean pine (Pinus koraiensis) synzoochorous interactions and the SDE in the same secondary forests with two treatments. Both treatments had seed source limitations: one was caused by the disappearance of Korean pine due to the historical disturbance, the other by pinecone harvesting in Korean pine plantations adjacent to the secondary forests. Thinning with different intensities (control, 25%, and 50%) were also performed to further explore the synzoochorous interactions and SDE in response to silvicultural management in the second type of forests. Results Source limitation increased the proportion of pre- and post-dispersal seed predation, and made the granivores-Korean pine interaction shift more towards antagonism, with the estimated SDE of 2.31 and 3.60, respectively, for the secondary forests without and with Korean pine. Thinning with different intensities did not alleviate the reactions towards antagonism but altered SDE; granivores occurrence decreased, but the proportion of pre- and post-dispersal seed predation increased, resulting in a fivefold decreased seedling recruitment in 25% thinning (the lowest SDE of 0.26). Conclusion The source limitation coupling thinning biased the synzoochorous interactions more towards antagonism and significantly lowered granivore-mediated SDE, which limited the successful recruitment of Korean pine in secondary forests. Forest managers should control pinecone harvesting, protect the synzoochorous interaction, and take into account masting event for Korean pine regeneration in the future.

A systematic review and meta-analysis of vineyard techniques used to delay ripening.

Several vineyard techniques have been proposed to delay grape maturity in light of the advanced maturation driven by increasingly frequent water and heat stress events that are detrimental to grape quality. These studies differ in terms of their experimental conditions, and in the present work we have attempted to summarize previous observations in a quantitative, data-driven systematic review. A meta-analysis of quantitative data gathered across 43 relevant studies revealed the overall significance of the proposed treatments and evaluated the impact of different experimental conditions on the outcome of antitranspirants, delayed pruning and late source limitation. Antitranspirants were most effective when applied twice and closer to veraison, while di-1-p-menthene increased the ripening delay by about 1°Brix compared to kaolin. Larger ripening delays were achieved with delayed pruning of low-yielding vines or by pruning at later stages of apical bud development. Late defoliation or shoot trimming delayed ripening in high-yielding vines and represent suitable solutions for late-harvested varieties, but became ineffective where the treatment decreased yield. This quantitative meta-analysis of 242 primary observations uncovers factors affecting the efficacy of vineyard practices to delay ripening, which should be carefully considered by grape growers attempting to achieve this outcome.

Tree-Ring Isotopes Provide Clues for Sink Limitation on Treeline Formation on the Tibetan Plateau

Identifying what determines the high elevation limits of tree growth is crucial for predicting how treelines may shift in response to climate change. Treeline formation is either explained by a low-temperature restriction of meristematic activity (sink limitation) or by the photosynthetic constraints (source limitation) on the trees at the treeline. Our study of tree-ring stable isotopes in two Tibetan elevational transects showed that treeline trees had higher iWUE than trees at lower elevations. The combination of tree-ring δ13C and δ18O data further showed that photosynthesis was higher for trees at the treeline than at lower elevations. These results suggest that carbon acquisition may not be the main determinant of the upper limit of trees; other processes, such as immature tissue growth, may be the main cause of treeline formation. The tree-ring isotope analysis (δ13C and δ18O) suggests that Tibetan treelines have the potential to benefit from ongoing climate warming, due to their ability to cope with co-occurring drought stress through enhanced water use efficiency.

Hydrological controls of DOC export from Nordic headwater catchments.

<p>Nordic surface waters are currently much browner than during the 1980s due to drivers related to decreased acid deposition, and increased precipitation. While upward trends in concentration of DOC have been well documented, positive trends in the annual export of DOC are not as widespread. The variation in seasonality of DOC export may mask long-term trends in annual export. A large dataset of 30 natural headwater catchments from Finland, Norway, and Sweden contains more than 20 years of discharge and DOC records. We will use these data to better quantify the trends of DOC export and their relationships to seasonality and the effects of climatic changes seen over the last few decades, such as diminished snowpack, less distinct snowmelt events and increases in autumn precipitation. We will investigate both the seasonal and annual relationships between DOC concentration and discharge (C-Q) and test if they relate to time and catchment characteristics such as size, latitude, and landcover.</p><p>We explore 3 hypotheses in this data set. First, spring DOC export is decreased due to less distinct snowmelt and runoff events while autumn export of DOC is increased as a consequence of more autumn runoff. Second, we propose that catchments with a longer or more distinct snow cover period are more sensitive than catchments at lower elevation or latitude due to the length of inactivity caused by low temperatures and a more defined snowmelt runoff event. Third, we hypothesize the negative C-Q relationship in winter and spring is likely due to source limitation and dilution while hydrologic controls in summer and autumn are associated with positive C-Q relationships.</p><p>Climate change is promoting enhanced export of DOC from soils towards surface waters, leading to more carbon processed and transported along the aquatic continuum from headwaters to coast. This data set gives us an opportunity to look at a diverse set of headwater catchments in the Nordic region, an area disproportionally affected by climate change, to clarify the hydrologic components and how this will affect overall carbon transport. </p>

Water Pollution foundation Detection and Localization Based on Wireless Sensor Networks

Water contamination cause recognition is the prerequisite of water contamination foundation restriction. In belowmagazine, the resource identification issues of the system are proposed. To take care of the identification issues of static and dynamic contamination cause, the speculation investigation technique is applied. To make up the deficiencies of the smutty contamination source confinement calculation and the restriction techniques dependent on the dispersion models in water, a contamination source limitation calculation dependent on focus form is likewise projected. In the strategy for recognition, the related parallel theories, test measurements and the particular assessment strategies are given. In recreation analyzes, the source discovery strategies are tried. In strategy for restriction, the area of the source is gotten by the mathematical design highlight of the form. The outcomes show that the exhibition of the proposed calculation is better than different strategies when the focus shape is axis-symmetric. What's more, in contamination source location of the hub if the quantity of tests can be guaranteed, the less perception times might be more useful to get high discovery precision.

Travel Data Sequence from Multi-Source Recommendation System

Due to different sort of preferences and restrictions of a trip such as time source limitation and every tourist’s destination points the travel based recommendation has become a challenging task. Most importantly the data generated by the geo-tagged social channel from the geo based tag tweets, snapshots of credentials. Due to examining this, extended data allows us to invent the profiles, daily mobility patterns, and results of the user’s. To resolve the issues and challenges of capacity providing their personalized and sequential travel to make package recommendation to a topical package model and to take using social media info in which mechanically mine person travel interest with another quality like time, cost, and period of wayfaring. Here, we had a proposal that a travel data sequence after a multi source recommendation system. We implemented a location recommendation system that derives personal preferences while accounting for restraints irremissibly by road capacity in order to change the demand of travel. We first infer unobserved preferences using a machine learning technique from data mining records. It extends our method to provide personalized suggestions based on user geo co-ordinates points. By utilizing the tree based hierarchal graphs (TBHG), location histories of the multiple users’ have been modeled. In order to collect the selected places interest level and travel knowledge of user’s, the HITS model had developed based on TBHG. Finally, hybrid filtering approach based on HITS is utilized to get the global positioning system (GPS) based personalized recommendation system. And for image based search similar images with the tag information are retrieved for the query image users.

EFFECT OF MECHANICAL HARVESTING ON YIELD AND QUALITY OF TEA IN TANZANIA

SUMMARYHand plucking of tea is labour intensive, and with rising labour costs mechanical harvesting (MH) is of increasing interest. However, effects of MH on yield and quality of tea remain unclear. We harvested two tea clones for eight years with a small, wheeled machine, to investigate effects of different cutting heights on yield and quality. The harvest interval for machine plots was 40% longer than for hand plucking in the first three years and 100% longer thereafter. The yield response, relative to hand plucking, depended on cutting height. Provided that increase in bush height (table rise) was 6 cm per year or less, yields were 15–21% higher than with hand plucking and increased yield was still being maintained after eight years. The increase in yield appeared to be mainly attributable to the longer harvest interval for machine plots, so that larger shoots were harvested. There was no increase in the number of shoots harvested per year, despite more intensive plucking with the machine. In less intensively harvested plots, where table rise was 11–14 cm per year, yield was reduced compared to hand plucking, and shoot number was nearly 30% lower. Dry matter production was greatest under the least intensive harvesting, but greater intensity gave higher harvest index and yield. In plots with no table rise, but not in other plots, a large amount of die-back of plucked points was observed. This may indicate source limitation of shoot numbers. We conclude that, with an extended harvest interval and careful management of cutting height, the yield of tea can be maintained under MH. There was a reduction in green leaf quality, with coarser shoots and increased mature leaf, but a limited number of taster evaluations of quality of the black tea showed significant differences for only one clone.