scholarly journals Trade-offs between environmental and economic factors in conversion from exotic pine production to natural regeneration on erosion prone land

2021 ◽  
Vol 51 ◽  
Author(s):  
Suzanne Lambie ◽  
Shaun Awatere ◽  
Adam Daigneault ◽  
Miko Kirschbaum ◽  
Michael Marden ◽  
...  
Keyword(s):  
Natural Regeneration ◽  
Forest Cover ◽  
Regional Scale ◽  
Cost Benefit ◽  
Native Forest ◽  
Limited Information ◽  
Honey Production ◽  
Trade Offs ◽  
Erosion Mitigation ◽  
Very High

Background: Some of New Zealand’s exotic pine (Pinus radiata D.Don) forests were planted for erosion mitigation but cultural, legislative, environmental, and profitability limitations in some parts of the landscape have led to reassessment of their suitability. There is limited information to support landowner decisions on the viability of natural regeneration of native forest post-pine-harvest. Methods: We evaluated scenarios of post-harvest natural regeneration, compared to remaining in pine production, using erosion susceptibility determined from historical occurrence of landslides, gullies and earthflows, biophysical growth modelling of mānuka–kānuka (Leptospermum scoparium-Kunzea ericoides (A.Rich) Joy Thomps.) shrubland using the process-based CenW model, and cost-benefit analyses using NZFARM with two land use change scenarios, at two levels of erosion mitigation ± honey profits. Results: In our study area, the Gisborne Region (North Island of New Zealand), ~27% of the land has moderate–very high susceptibility to landslides, 14–22% a high probability of contributing material to waterways, and 19% moderate–very high gully erosion susceptibility. Pines grow 10 times faster than naturally regenerating mānuka–kānuka shrubland, but mānuka–kānuka is used for honey not wood production. Natural regeneration resulted in losses of $150–250 ha-1 yr-1 compared to the current profitability of pine production. Honey production offset some reduction in pine revenue, but not fully. Thus, the viability of shifting from pines to native forest is highly dependent on landowner impetus and value for non-market ecosystem services (such as cultural and biodiversity values) provided by native forest. Conclusions: A mosaic of land uses within a property may sufficiently offset income losses with other benefits, whereby highly erosion-prone land is shifted from rotational pine forest production to permanent native forest cover with honey production where possible. At the regional scale in Gisborne, the conversion of the most highly susceptible land under production forestry (315–556 ha) to natural regeneration has the potential for wider benefits for soil conservation reducing erosion by 1–2.5 t yr–1 of sediment facilitating achievement of cleaner water aspirations and habitat provision.  

scholarly journals Niches, rather than neutrality, structure a grassland pioneer guild

2005 ◽  
Vol 272 (1570) ◽  
pp. 1357-1364 ◽  
Author(s):  
Lindsay A Turnbull ◽  
Liz Manley ◽  
Mark Rees
Keyword(s):  
Seed Size ◽  
Adult Stage ◽  
Niche Differentiation ◽  
Competitive Dynamics ◽  
Similar Species ◽  
Adult Density ◽  
Pioneer Species ◽  
Trade Offs ◽  
Very High ◽  
Early Establishment

Pioneer species are fast-growing, short-lived gap exploiters. They are prime candidates for neutral dynamics because they contain ecologically similar species whose low adult density is likely to cause widespread recruitment limitation, which slows competitive dynamics. However, many pioneer guilds appear to be differentiated according to seed size. In this paper, we compare predictions from a neutral model of community structure with three niche-based models in which trade-offs involving seed size form the basis of niche differentiation. We test these predictions using sowing experiments with a guild of seven pioneer species from chalk grassland. We find strong evidence for niche structure based on seed size: specifically large-seeded species produce fewer seeds but have a greater chance of establishing on a per-seed basis. Their advantage in establishment arises because there are more microsites suitable for their germination and early establishment and not directly through competition with other seedlings. In fact, seedling densities of all species were equally suppressed by the addition of competitors' seeds. By the adult stage, despite using very high sowing densities, there were no detectable effects of interspecific competition on any species. The lack of interspecific effects indicates that niche differentiation, rather than neutrality, prevails.

scholarly journals Native forest replacement by exotic plantations in southern Chile (1985–2011) and partial compensation by natural regeneration

2015 ◽  
Vol 345 ◽  
pp. 10-20 ◽  
Author(s):  
Carlos Zamorano-Elgueta ◽  
José María Rey Benayas ◽  
Luis Cayuela ◽  
Stijn Hantson ◽  
Dolors Armenteras
Keyword(s):  
Natural Regeneration ◽  
Native Forest ◽  
Southern Chile ◽  
Exotic Plantations ◽  
Partial Compensation

Experimental field exclosure of birds and bats in agricultural systems — Methodological insights, potential improvements, and cost-benefit trade-offs

2019 ◽  
Vol 35 ◽  
pp. 1-12 ◽  
Author(s):  
Bea Maas ◽  
Sacha Heath ◽  
Ingo Grass ◽  
Camila Cassano ◽  
Alice Classen ◽  
...  
Keyword(s):  
Cost Benefit ◽  
Agricultural Systems ◽  
Experimental Field ◽  
Trade Offs

Sustainable Distribution Design: Contrasting Disposable, Recyclable, and Reusable Strategies for Packaging Materials Using a Total Cost Analysis With an Illustration of Milk Distribution

2010 ◽  
Author(s):  
Sri Satya Kanaka Nagendra Jayanty ◽  
William J. Sawaya ◽  
Michael D. Johnson
Keyword(s):  
Cost Benefit ◽  
Packaging Materials ◽  
Policy Makers ◽  
Specific Product ◽  
Cost Structures ◽  
Trade Offs ◽  
Technological Advances ◽  
The Cost ◽  
Total Cost Analysis ◽  
Plastic Containers

Engineers, policy makers, and managers have shown increasing interest in increasing the sustainability of products over their complete lifecycles and also from the ‘cradle to grave’ or from production to the disposal of each specific product. However, a significant amount of material is disposed of in landfills rather than being reused in some form. A sizeable proportion of the products being dumped in landfills consist of packaging materials for consumable products. Technological advances in plastics, packaging, cleaning, logistics, and new environmental awareness and understanding may have altered the cost structures surrounding the lifecycle use and disposal costs of many materials and products resulting in different cost-benefit trade-offs. An explicit and well-informed economic analysis of reusing certain containers might change current practices and results in significantly less waste disposal in landfills and in less consumption of resources for manufacturing packaging materials. This work presents a method for calculating the costs associated with a complete process of implementing a system to reuse plastic containers for food products. Specifically, the different relative costs of using a container and then either disposing of it in a landfill, recycling the material, or reconditioning the container for reuse and then reusing it are compared explicitly. Specific numbers and values are calculated for the case of plastic milk bottles to demonstrate the complicated interactions and the feasibility of such a strategy.

Development of a High Specific Speed Centrifugal Compressor

1996 ◽  
Author(s):  
C. Rodgers
Keyword(s):  
Centrifugal Compressor ◽  
Test Performance ◽  
Pressure Ratio ◽  
High Volume ◽  
Limited Information ◽  
Component Test ◽  
Booster Compressor ◽  
Specific Speed ◽  
Stage Efficiency ◽  
Very High

This paper describes the development of a subscale single stage centrifugal compressor with a dimensionless specific speed (Ns) of 1.8, originally designed for full size appllcatioa as a high volume flow, low pressure ratio, gas booster compressor. The specific stage is noteworthy in that it provides a benchmark representing the performance potential of very high specific speed compressors of which limited information is found in open literature. Stage & component test performance characteristics are presented together with traverse results at the impeller exit. Traverse test results were compared with recent CFD computational predictions, for a exploratory analytical callbration of a very high specific speed impeller geometry. The tested subscale (0.583) compressor essentially satisfied design performance expectations with an overall stage efficiency of 74% incinding, excessive exit casing losses. It was estimated that stage efficiency could be increased to 81% with exit casing losses halved.

scholarly journals Natural Regeneration of the Tree Stand in the Bilberry Spruce Forest—Clear-Cutting Ecotone Complex in the First Post-Logging Decade

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1542
Author(s):  
Nadezhda V. Genikova ◽  
Viktor N. Mamontov ◽  
Alexander M. Kryshen ◽  
Vladimir A. Kharitonov ◽  
Sergey A. Moshnikov ◽  
...  
Keyword(s):  
Natural Regeneration ◽  
Forest Canopy ◽  
Forest Cover ◽  
Forest Type ◽  
Ground Cover ◽  
Woody Species ◽  
Forest Edge ◽  
Tree Canopy ◽  
Clear Cut ◽  
Clear Cutting

Bilberry spruce forests are the most widespread forest type in the European boreal zone. Limiting the clear-cuttings size leads to fragmentation of forest cover and the appearance of large areas of ecotone complexes, composed of forest (F), a transition from forest to the cut-over site under tree canopy (FE), a transition from forest to the cut-over site beyond tree canopy (CE), and the actual clear-cut site (C). Natural regeneration of woody species (spruce, birch, rowan) in the bilberry spruce stand—clear-cut ecotone complex was studied during the first decade after logging. The effects produced by the time since cutting, forest edge aspect, and the ground cover on the emergence and growth of trees and shrubs under forest canopy and openly in the clear-cut were investigated. Estimating the amount and size of different species in the regeneration showed FE and CE width to be 8 m—roughly half the height of first-story trees. Typical forest conditions (F) feature a relatively small amount of regenerating spruce and birch. The most favorable conditions for natural regeneration of spruce in the clear-cut—mature bilberry spruce stand ecotone are at the forest edge in areas of transition both towards the forest and towards the clear-cut (FE and CE). Clear-cut areas farther from the forest edge (C) offer an advantage to regenerating birch, which grows densely and actively in this area.

scholarly journals Could aerosol emissions be used for regional heat wave mitigation?

2012 ◽  
Vol 12 (9) ◽  
pp. 23793-23828
Author(s):  
D. N. Bernstein ◽  
J. D. Neelin ◽  
Q. B. Li ◽  
D. Chen
Keyword(s):  
Los Angeles ◽  
Heat Wave ◽  
Heat Waves ◽  
Regional Scale ◽  
Middle Part ◽  
Emission Rates ◽  
Sulfate Aerosols ◽  
Geographical Differences ◽  
Aerosol Emission ◽  
Trade Offs

Abstract. Geoengineering applications by injection of sulfate aerosols into the stratosphere are under consideration as a measure of last resort to counter global warming. Here adaptation to a potential regional scale application to offset the impacts of heat waves is critically examined. The effect of regional scale sulfate aerosol emission over California in each of two days of the July 2006 heat wave using the Weather Research and Forecasting model with fully coupled chemistry (WRF-Chem) is used to quantify potential reductions in surface temperature as a function of emission rates in the lower stratosphere. Over the range considered, afternoon temperature reductions scale almost linearly with injections. Local meteorological factors yield geographical differences in surface air temperature sensitivity. For emission rates of approximately 30 μg m−2 s−1 of sulfate aerosols (with standard WRF-Chem size distribution) over the region, temperature decreases of around 7 °C result during the middle part of the day over the Central Valley, one of the hardest hit by the heat wave. Regions more ventilated with oceanic air such as Los Angeles have slightly smaller reductions. The length of the hottest part of the day is also reduced. Advection effects on the aerosol cloud must be more carefully forecast for smaller injection regions. Verification of the impacts could be done via measurements of differences in reflected and surface downward shortwave. Such regional geoengineering applications with specific near-term target effects but smaller cost and side effects could potentially provide a means of testing larger scale applications. However, design trade-offs differ from global applications and the size of the required injections and the necessity of injection close to the target region raise substantial concerns. The evaluation of this regional scale application is thus consistent with global model evaluations emphasizing that mitigation via reduction of fossil fuels remains preferable to considering geoengineering with sulfate aerosols.

scholarly journals Central Mediterranean Sea forecast: effects of high-resolution atmospheric forcings

2006 ◽  
Vol 3 (3) ◽  
pp. 637-669 ◽  
Author(s):  
S. Natale ◽  
R. Sorgente ◽  
S. Gaberšek ◽  
A. Ribotti ◽  
A. Olita
Keyword(s):  
High Resolution ◽  
Ocean Circulation ◽  
Regional Scale ◽  
Circulation Model ◽  
Surface Current ◽  
Ocean Model ◽  
Central Mediterranean ◽  
Resolution Model ◽  
Atmospheric Forcings ◽  
Very High

Abstract. Ocean forecasts over the Central Mediterranean, produced by a near real time regional scale system, have been evaluated in order to assess their predictability. The ocean circulation model has been forced at the surface by a medium, high or very high resolution atmospheric forcing. The simulated ocean parameters have been compared with satellite data and they were found to be generally in good agreement. High and very high resolution atmospheric forcings have been able to form noticeable, although short-lived, surface current structures, due to their ability to detect transient atmospheric disturbances. The existence of the current structures has not been directly assessed due to lack of measurements. The ocean model in the slave mode was not able to develop dynamics different from the driving coarse resolution model which provides the boundary conditions.

scholarly journals COVID-19: Rethinking the Lockdown Groupthink

2021 ◽  
Vol 9 ◽  
Author(s):  
Ari R. Joffe
Keyword(s):  
Public Health ◽  
High Risk ◽  
Cost Benefit Analysis ◽  
Health Care Systems ◽  
Herd Immunity ◽  
Cost Benefit ◽  
Risk Groups ◽  
School Closures ◽  
Trade Offs ◽  
Care Systems

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused the Coronavirus Disease 2019 (COVID-19) worldwide pandemic in 2020. In response, most countries in the world implemented lockdowns, restricting their population's movements, work, education, gatherings, and general activities in attempt to “flatten the curve” of COVID-19 cases. The public health goal of lockdowns was to save the population from COVID-19 cases and deaths, and to prevent overwhelming health care systems with COVID-19 patients. In this narrative review I explain why I changed my mind about supporting lockdowns. The initial modeling predictions induced fear and crowd-effects (i.e., groupthink). Over time, important information emerged relevant to the modeling, including the lower infection fatality rate (median 0.23%), clarification of high-risk groups (specifically, those 70 years of age and older), lower herd immunity thresholds (likely 20–40% population immunity), and the difficult exit strategies. In addition, information emerged on significant collateral damage due to the response to the pandemic, adversely affecting many millions of people with poverty, food insecurity, loneliness, unemployment, school closures, and interrupted healthcare. Raw numbers of COVID-19 cases and deaths were difficult to interpret, and may be tempered by information placing the number of COVID-19 deaths in proper context and perspective relative to background rates. Considering this information, a cost-benefit analysis of the response to COVID-19 finds that lockdowns are far more harmful to public health (at least 5–10 times so in terms of wellbeing years) than COVID-19 can be. Controversies and objections about the main points made are considered and addressed. Progress in the response to COVID-19 depends on considering the trade-offs discussed here that determine the wellbeing of populations. I close with some suggestions for moving forward, including focused protection of those truly at high risk, opening of schools, and building back better with a economy.

scholarly journals Uncertainty Analysis of Multisource Land Cover Products in China

2021 ◽  
Vol 13 (16) ◽  
pp. 8857
Author(s):  
Longhao Wang ◽  
Jiaxin Jin
Keyword(s):  
Land Cover ◽  
Forest Cover ◽  
Regional Scale ◽  
Least Squares Regression ◽  
Average Deviation ◽  
Deviation Analysis ◽  
Land Cover Data ◽  
Spatial Changes ◽  
Forest Coverage ◽  
High Consistency

Satellite-based land cover products play a crucial role in sustainability. There are several types of land cover products, such as qualitative products with discrete classes, semiquantitative products with several classes at a predetermined ratio, and quantitative products with land cover fractions. The proportions of land cover types in the grids with coarse resolution should be considered when used at the regional scale (e.g., modeling and remote sensing inversion). However, uncertainty, which varies with spatial distribution and resolution, needs to be studied further. This study used MCD12, ESA CCI, and MEaSURES VCF land cover data as indicators of qualitative, semiquantitative, and quantitative products, respectively, to explore the uncertainty of multisource land cover data. The methods of maximum area aggregation, deviation analysis, and least squares regression were used to investigate spatiotemporal changes in forests and nontree vegetation at diverse pixel resolutions across China. The results showed that the average difference in forest coverage for the three products was 8%, and the average deviation was 11.2%. For forest cover, the VCF and ESA CCI exhibited high consistency. For nontree vegetation, the ESA CCI and MODIS exhibited the lowest differences. The overall uncertainty in the temporal and spatial changes of the three products was relatively small, but there were significant differences in local areas (e.g., southeastern hills). Notably, as the spatial resolution decreased, the three products’ uncertainty decreased, and the resolution of 0.1° was the inflection point of consistency.

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