scholarly journals Spatiotemporal Variation in Pollination Deficits in an Insect-Pollinated Dioecious Crop

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1273
Author(s):  
Helena Castro ◽  
Catarina Siopa ◽  
Vinícius Casais ◽  
Mariana Castro ◽  
João Loureiro ◽  
...  

Inadequate quantity and quality of pollen reaching the stigmas decreases the sexual reproductive output of plants, compromising yield. Still, the current extent of pollen limitation affecting yield (i.e., pollination deficits) is poorly quantified. This study is aimed at quantifying pollination deficits in kiwifruit orchards, a dioecious plant with a fruit caliber and market value largely dependent on pollination services. For that, we set up a pollination experiment and quantified services and yield provided by current pollination vectors, and under optimal pollination, over two years in a total of twenty-three orchards covering the kiwifruit production range in Portugal. We characterized nine fruit traits and used: (1) fruit weight to calculate pollination deficits and relate them with pollinator diversity and abundance, and environmental variables; and (2) production values, fruit caliber, and market values to calculate economic impact of pollination deficits. Results showed that pollination deficits were variable in time and space and were significantly and negatively correlated with pollinator abundance, while the opposite pattern was obtained for production, supporting the notion that a higher pollinator’s abundance is related to lower pollination deficits and higher yields. Understanding the factors affecting pollination deficits is crucial to depict the need for nature-based solutions promoting pollinators and to resort to management practices assisting pollination.

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 431
Author(s):  
Caroline Wentling ◽  
Felipe S. Campos ◽  
João David ◽  
Pedro Cabral

As urbanization and agriculture increase worldwide, habitats and food sources for wild pollinators are often fragmented or destroyed. As wild pollinators contribute both resilience and variety to agricultural fields, it is desirable to implement land management practices that preserve their well-being and ability to contribute to food production systems. This study evaluates continental Portugal for its change in suitability to host bee’s pollinator species (Apis mellifera) from 1990 to 2018. It uses the InVEST crop pollination modeling tool and CORINE Land Cover, as well as parameterization to produce pollinator abundance and supply maps. These are generalized to municipality boundaries to provide actionable insights to farmers and policymakers and strengthen land management practices. It finds that the potential for pollination services is growing, with averages of both pollinator abundance and supply indices improving by 8.76% across the continental territory in 28 years. The study results are validated using another pollination index derived from a study that is based on expert opinion and field sampling in a sub-region of Portugal. This method of aggregation of model results and comparison of the percent difference by administrative boundary has the potential to better inform both policymakers and farmers about the pollination potential on a local level, as well as inspire interventions for future productivity.


2021 ◽  
Author(s):  
Hollie Blaydes ◽  
Alona Armstrong ◽  
Duncan Whyatt ◽  
Simon Potts ◽  
Emma Gardner

<p>Solar photovoltaics (PV) is projected to become the dominant renewable, with much capacity being installed as ground-mounted solar parks. Land use change for solar can affect ecosystems across various spatial scales and solar parks offer a unique opportunity for ecological enhancement. One compelling potential benefit put in practice by the solar industry is management for insect pollinators. Specifically, solar parks can provide refuge for pollinators through the provision of suitable habitat, potentially contributing to halting and reversing widespread declines recorded in a number of pollinator groups. There is scope to both manage and design solar parks for pollinators, but understanding is limited. Using a combination of GIS and a process-based pollinator model, we explore how solar park size, shape and management could affect ground-nesting bumblebee abundance inside solar parks and surrounding landscapes in the UK. We show that within solar parks, the floral resources provided by different management practices is a key factor affecting bumblebee abundance, but the impacts are dependent on landscape context. In comparison, solar park size and shape have a lesser impact. Moreover, the effects of both solar park management and design extend into the surrounding landscape, affecting bumblebee abundance up to 1 km away from the solar park. If designed and managed optimally, solar parks therefore have the potential to boost local pollinator abundance and pollination services to surrounding land. Our results demonstrate how incorporating biodiversity into solar park design and management decisions could benefit groups such as pollinators and contribute to the wider environmental sustainability of solar parks.</p>


2018 ◽  
Vol 68 (12) ◽  
pp. 2941-2947
Author(s):  
George Ungureanu ◽  
Gabriela Ignat ◽  
elena Leonte ◽  
Carmen Luiza Costuleanu ◽  
Nicoleta Stanciu ◽  
...  

The problem associated with the household behavior on solid waste disposal site in today�s society is complex because of the large quantity and diverse nature of the wastes. Due increase the population, rapid development, global agricultural development has moved rapidly, limitations of financing, emerging limitations of both energy and raw materials and also add to the complexity of any waste management system, large quantities of wastes are being generated in different forms such as solid, liquid and gases. This research explored factors affecting the level of participation in solid waste segregation and recycling of households in Romania, as well as examining current Romania households waste management practices and their knowledge of waste management. This study investigated the solid waste situation and the organization of solid waste management in both urban and rural settings from the perspective of households. Solid waste management is a key component of public services which needs to serve the urban and rural municipalities in an efficient way in order to maintain a decent standard of public health.


2021 ◽  
Vol 13 (13) ◽  
pp. 7007
Author(s):  
Habtamu Nebere ◽  
Degefa Tolossa ◽  
Amare Bantider

In Ethiopia, the practice of land management started three decades ago in order to address the problem of land degradation and to further boost agricultural production. However, the impact of land management practices in curbing land degradation problems and improving the productivity of the agricultural sector is insignificant. Various empirical works have previously identified the determinants of the adoption rate of land management practices. However, the sustainability of land management practices after adoption, and the various factors that control the sustainability of implemented land management practices, are not well addressed. This study analyzed the factors affecting the sustainability of land management practices after implementation in Mecha Woreda, northwestern Ethiopia. The study used 378 sample respondents, selected by a systematic random sampling technique. Binary logistic regression was used to analyze the quantitative data, while the qualitative data were qualitatively and concurrently analyzed with the quantitative data. The sustained supply of fodder from the implemented land management practices, as well as improved cattle breed, increases the sustainability of the implemented land management practices. While lack of agreement in the community, lack of enforcing community bylaws, open cattle grazing, lack of benefits of implemented land management practices, acting as barrier for farming practices, poor participation of household heads during planning and decision-making processes, as well as the lack of short-term benefits, reduce the sustainability of the implemented land management practices. Thus, it is better to allow for the full participation of household heads in planning and decision-making processes to bring practical and visible results in land management practices. In addition, recognizing short-term benefits to compensate the land lost in constructing land management structures must be the strategy in land management practices. Finally, reducing the number of cattle and practicing stall feeding is helpful both for the sustainability of land management practices and the productivity of cattle. In line with this, fast-growing fodder grass species have to be introduced for household heads to grow on land management structures and communal grazing fields for stall feeding.


2017 ◽  
Vol 47 (1) ◽  
pp. 32-65 ◽  
Author(s):  
Dong Won Shin ◽  
Laura McCann

This study explores factors affecting adoption of two stormwater management practices, rain gardens and rain barrels. Mail survey data from Columbia, Missouri indicate adoption rates of 3.12 percent (rain gardens) and 7.47 percent (rain barrels). This unique dataset enables us to distinguish among nonadopters using knowledge levels, and to investigate the effect of practice-specific barriers. Clustered multinomial logistic regressions reveal serious gardeners are more likely to adopt both practices. Specific barriers differ by practice and type of nonadopter. Adding practice-specific barriers increased pseudo R2 values from 0.12 to 0.22 for rain gardens and from 0.13 to 0.26 for rain barrels.


2011 ◽  
Vol 243-249 ◽  
pp. 4375-4380
Author(s):  
Yuan Chun Huang ◽  
Jian Li ◽  
Haize Pan

Through analyzing the factors affecting passengers’ path-choice, the corresponding principles and rules of the ticket income distribution are put forward and the new model of the Urban Rail Transit Network in Beijing is set up in the paper. Through the deformation of the urban rail transit and the simplification of the lines, the topology of the urban rail transit lines is abstracted into an undirected connection graph. Breadth-priority optimization algorithm is applied to search the effective paths between the OD and the flow-matching ratio is acquired by calculating based on multi-factor matching algorithm, in which many relevant numerical examples are analyzed to verify the feasibility of the dual-ratio method and to summarize the characteristics of the project.


2021 ◽  
Vol 5 (1) ◽  
pp. 411-417
Author(s):  
Salamatu Suleiman ◽  
Usman Kibbon Adamu ◽  
Jibril Abdullahi

This study examined the soil management practices of farmers in Zaria Local Government Area, Kaduna state, Nigeria. Both primary and secondary means of data collection were employed in the study. Purposive sampling technique was used to select both the study locations and the respondents based on the characteristics of the population and the objectives of the study. The sample size of 384 copies of questionnaire was purposively used to acquire data from the selected respondents. This was analyzed in SPSS 2.0 version, using simple descriptive statistics such as frequencies, percentages and mean derived from 4-point Likert scale. The study indicated that the most adopted soil management practice by the respondents was the use of animal manure with 28.1%. This is followed by Mixed Cropping (26.3%). while shifting cultivation is the least practice (1.7%). The results also revealed that manure application is the most effective soil management practice with a mean score of ( = 4.21). while the lowest mean score is zero tilling with a value of ( = 1.51). Findings also showed that Soil fertility depletion is the strongest challenge to soil management practices with 32.9%.  The paper concludes that farmers in the study area can adopt many soil management practices. The paper recommends that there is need for mobile advisory teams of agricultural extension agents and the N-power agro unit to be set up, equipped, mobilized to reach out farmers to increase their awareness on adoption of improved agro soil management practices through training and consultation with farmers.


2021 ◽  
Author(s):  
Stephen J Trueman ◽  
Wiebke Kämper ◽  
Joel Nichols ◽  
Steven M Ogbourne ◽  
David Hawkes ◽  
...  

Abstract Background and Aims Pollen limitation is most prevalent among bee-pollinated plants, self-incompatible plants, and tropical plants. However, we have very little understanding of the extent to which pollen limitation affects fruit set in mass-flowering trees despite tree crops accounting for at least 600 million tons of the 9,200 million tons of annual global food production. Methods We determined the extent of pollen limitation in a bee-pollinated, partially self-incompatible, subtropical tree by hand cross-pollinating the majority of flowers on mass-flowering macadamia (Macadamia integrifolia) trees that produce about 200,000–400,000 flowers. We measured tree yield and kernel quality and estimated final fruit set. We genotyped individual kernels by MassARRAY to determine levels of outcrossing in orchards and assess paternity effects on nut quality. Key Results Macadamia trees were pollen limited. Supplementary cross-pollination increased nut-in-shell yield, kernel yield and fruit set by as much as 97%, 109% and 92%, respectively. The extent of pollen limitation depended upon the proximity of experimental trees to trees of another cultivar because macadamia trees were highly outcrossing. Between 84% and 100% of fruit arose from cross-pollination, even at 200 m (25 rows) from orchard blocks of another cultivar. Large variations in nut-in-shell mass, kernel mass, kernel recovery and kernel oil concentration were related to differences in fruit paternity, including between self-pollinated and cross-pollinated fruit, thus demonstrating pollen-parent effects on fruit quality, i.e. xenia. Conclusions This study is the first to demonstrate pollen limitation in a mass-flowering tree. Improved pollination led to increased kernel yield of 0.31–0.59 tons per hectare, which equates currently to higher farm-gate income of approximately US3,720–US7,080 per hectare. The heavy reliance of macadamia flowers on cross-pollination and the strong xenia effects on kernel mass demonstrate the high value that pollination services can provide to food production.


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