scholarly journals Changes in mean forest age in Canada’s forests could limit future increases in area burned but compromise potential harvestable conifer volumes

2017 ◽  
Vol 47 (6) ◽  
pp. 755-764 ◽  
Author(s):  
Yan Boulanger ◽  
Martin Girardin ◽  
Pierre Y. Bernier ◽  
Sylvie Gauthier ◽  
André Beaudoin ◽  
...  
Keyword(s):  
Simulation Models ◽  
Stand Age ◽  
Almost Everywhere ◽  
Age Related ◽  
New Information ◽  
Simple Simulation ◽  
Regional Vulnerability ◽  
Vegetation Feedbacks ◽  
Burning Rates ◽  
Negative Impacts

Forest fire activity is projected to increase with climate change in Canada, but vegetation feedbacks are usually not considered. Using new information on the selectivity or avoidance of fire as a function of stand age and composition, we ran simple simulation models that consider the changes in the regional age matrices induced by fire and harvesting to project future burn rates. We also projected estimated future regional vulnerability of timber supply to fire by considering these new burn rates. The inclusion of age-related feedbacks would have a large impact on projected increases in burn rates, mostly in a very fire active zone under aggressive climate forcing. Projected burn rates would still increase, but would be 50% less in 2100 than if projected without this biotic feedback in some zones. Negative feedbacks would be virtually nonexistent when potential burning rates are below 1%, whereas realized burning rates would be lowered by more than a 0.5 percentage point when potential burning rates exceed 2.5%. Including fire–vegetation feedbacks had virtually no impact on total volume harvested. As fire burns more old-growth coniferous stands, slightly negative impacts were projected on conifer harvested almost everywhere. These results underline the need to incorporate fire–vegetation feedbacks when projecting future burn rates.

scholarly journals Combined effects of landscape composition and pesticide use on herbivore and pollinator functions in smallholder farms

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Quentin Struelens ◽  
Diego Mina ◽  
Olivier Dangles
Keyword(s):  
Smallholder Farmers ◽  
Cropping Systems ◽  
Cropping System ◽  
Landscape Composition ◽  
Pesticide Use ◽  
Combined Effects ◽  
Pollinator Abundance ◽  
New Information ◽  
Negative Impacts ◽  
Effect On Yield

Abstract Background Landscape composition has the potential to foster regulating ecosystem services such as pollination and biocontrol in temperate regions. However, most landscape studies do not take pesticide use into account even though it is the main control strategy worldwide and has negative impacts on beneficial insects. Moreover, few studies have explored these combined effects in smallholder cropping system with diverse landscapes and small cultivated fields. Methods We assessed the effect of semi-natural cover and pesticide use on pollinator and herbivore abundances and functions in 9 fields in the Ecuadorian Andes through participatory experiments with smallholder farmers. We performed a path analysis to quantify the effects of landscape and pesticide use on herbivory, pollination and ultimately yield. Results Pesticide use significantly reduced pollinator abundance but had no significant effect on pest abundance. Similarly, we found non-significant effects of landscape composition on either herbivory and pollination. The study also provides new information on understudied Andean lupine’s pests and pollinators, whose application for small farmers is discussed. Finally, we hypothesize that peculiarities of tropical smallholder cropping systems and landscapes could explain the non-significant landscape effects on insect-based processes, which calls for more research in places outside the well-studied temperate region. Conclusions Landscape composition did not show any significant effect on pest and pollinator while pesticide use decreased the abundance pollinators, but with no significant effect on yield. This study also provides information about Andean lupine reproduction and overcompensation mechanisms that could be of interest for local farmers and researchers of this understudied crop.

Do the Social Web 2.0 Media Foster Democratization?

2016 ◽  
pp. 314-330
Author(s):  
Rasoul Namazi
Keyword(s):  
Web 2.0 ◽  
Information Technologies ◽  
New Technologies ◽  
Authoritarian Regimes ◽  
Political Community ◽  
Political Information ◽  
The Internet ◽  
New Information ◽  
The Social ◽  
Negative Impacts

This chapter studies the influence of the Internet and new Web 2.0 technologies on the process of democratization in authoritarian regimes. The objective is to show that the new information technologies are not necessarily helpful to dissident movements and have even some negative impacts on the process of democratization. The author questions the capacity of Internet to transmit political information discusses how the new technologies contribute to the depoliticization of societies by creating passive citizens in authoritarian regimes. This chapter also shows how authoritarian regimes use new information technologies as instruments of control and repression and questions the effectiveness of the new cyber-activism by explaining the structure of the Internet and discussing the capacity of the new technologies in creating political community.

scholarly journals Simulation Modeling of the Sustainable Supply Chain

2020 ◽  
Vol 12 (15) ◽  
pp. 6007 ◽  
Author(s):  
Patrycja Hoffa-Dabrowska ◽  
Katarzyna Grzybowska
Keyword(s):  
Sustainable Development ◽  
Supply Chain ◽  
Global Economy ◽  
Simulation Models ◽  
Exhaust Emissions ◽  
Simulation Tool ◽  
Sustainable Supply Chain ◽  
Use Of Resources ◽  
Negative Impacts ◽  
The Impact

The development of the global economy affects the environment in which we are living, often in negative ways, including pollutions, exhaust emissions, depletion of natural resources, and other concerns. Therefore, it is so important to use resources in a reasonable, sustainable manner and to be aware of the impact of our activities on the environment, which in the next stage translates into trying to limit negative impacts to the environment. Aspects of sustainable supply chain (SSC) have become more and more popular in the last years. Entrepreneurs pay more attention to the aspect of sustainable development in their activities, especially to exhaust emissions. The rational use of resources is also a very important topic. Not only economic aspects but also environmental and social topics are taken into account in company politics, which is characteristic of sustainable development. The main purpose of this article is to show the benefits of SSC. For this purpose, the simulation models showing the supply chain and the sustainable supply chain will be built. The benefits of SSC in economic and environmental aspects will be presented using a computer simulation tool. Using a simulation tool fits in with sustainability; thanks to modeling supply chains in their virtuality and analysis, many resources can be saved in reality (for example, thanks to the consolidation of freight).

Stand age-related effects on soil respiration in a first rotation Sitka spruce chronosequence in central Ireland

2006 ◽  
Vol 0 (0) ◽  
pp. 070621084512039-???
Author(s):  
GUSTAVO SAIZ ◽  
KENNETH A. BYRNE ◽  
KLAUS BUTTERBACH-BAHL ◽  
RALF KIESE ◽  
VIOREL BLUJDEA ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Sitka Spruce ◽  
Stand Age ◽  
Age Related

scholarly journals Prediction of ovarian aging using ovarian expression of BMP15, GDF9, and C-KIT

2020 ◽  
Vol 245 (8) ◽  
pp. 711-719
Author(s):  
Min Jung Park ◽  
Jun-Woo Ahn ◽  
Ki Hyung Kim ◽  
Junghee Bang ◽  
Seung Chul Kim ◽  
...  
Keyword(s):  
Embryo Development ◽  
Ovarian Function ◽  
Antral Follicle ◽  
Antral Follicle Count ◽  
Development Rate ◽  
Ovarian Aging ◽  
Age Related ◽  
Morphogenetic Protein ◽  
New Information ◽  
Potential Biomarkers

This study investigated ovarian expressions of bone morphogenetic protein 15 (BMP15), growth differentiation factor 9 (GDF9), and C-KIT according to age in female mice to determine whether these factors can be served as new potential biomarkers of ovarian aging. Ovaries were collected from mice aged 10, 20, 30, and 40 weeks, and ovarian expressions of BMP15, GDF9, and C-KIT were examined by real-time PCR, Western blot, and immunohistochemistry. Follicle counts were measured on histological hematoxylin and eosin staining. In the second experiment to evaluate ovarian function, after superovulation with PMSG and hCG, the numbers of zygotes retrieved and embryo development rate were examined. Ovarian expressions of BMP15, GDF9, and C-KIT decreased with age. Follicle counts, numbers of retrieved zygotes, and embryo development rate were also significantly reduced in old mice over 30 weeks compared with young mice. These results indicate that these factors could be served as new potential biomarkers of ovarian aging. Impact statement Ovarian aging is becoming a more important issue in terms of fertility preservation and infertility treatment. Serum anti-Mullerian hormone (AMH) level and antral follicle count (AFC) are being practically used as markers of ovarian aging as well as ovarian reserve in human. However, these factors have some drawbacks in assessing ovarian aging and reserve. Therefore, the identification of ovarian expressions of BMP15, GDF9, and C-KIT according to female could be applied as a potent predictor of ovarian aging. This work provides new information on the development of diagnosis and treatment strategy of age-related fertility decline and premature ovarian insufficiency.

Stand age-related effects on soil respiration in rubber plantations (Hevea brasiliensis ) in southwest China

2019 ◽  
Vol 70 (6) ◽  
pp. 1221-1233 ◽  
Author(s):  
Jinbo Gao ◽  
Yiping Zhang ◽  
Qinghai Song ◽  
Youxing Lin ◽  
Ruiwu Zhou ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Hevea Brasiliensis ◽  
Southwest China ◽  
Stand Age ◽  
Rubber Plantations ◽  
Age Related

scholarly journals Mitochondrial Respiration Changes in R6/2 Huntington’s Disease Model Mice during Aging in a Brain Region Specific Manner

2020 ◽  
Vol 21 (15) ◽  
pp. 5412 ◽  
Author(s):  
Johannes Burtscher ◽  
Alba Di Pardo ◽  
Vittorio Maglione ◽  
Christoph Schwarzer ◽  
Ferdinando Squitieri
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Disease Model ◽  
Brain Regions ◽  
Future Research ◽  
Adult Mice ◽  
Age Related ◽  
Developmental Shift ◽  
Regional Vulnerability ◽  
Oxygen Conditions

Mitochondrial dysfunction is crucially involved in aging and neurodegenerative diseases, such as Huntington’s Disease (HD). How mitochondria become compromised in HD is poorly understood but instrumental for the development of treatments to prevent or reverse resulting deficits. In this paper, we investigate whether oxidative phosphorylation (OXPHOS) differs across brain regions in juvenile as compared to adult mice and whether such developmental changes might be compromised in the R6/2 mouse model of HD. We study OXPHOS in the striatum, hippocampus, and motor cortex by high resolution respirometry in female wild-type and R6/2 mice of ages corresponding to pre-symptomatic and symptomatic R6/2 mice. We observe a developmental shift in OXPHOS-control parameters that was similar in R6/2 mice, except for cortical succinate-driven respiration. While the LEAK state relative to maximal respiratory capacity was reduced in adult mice in all analyzed brain regions, succinate-driven respiration was reduced only in the striatum and cortex, and NADH-driven respiration was higher as compared to juvenile mice only in the striatum. We demonstrate age-related changes in respirational capacities of different brain regions with subtle deviations in R6/2 mice. Uncovering in situ oxygen conditions and potential substrate limitations during aging and HD disease progression are interesting avenues for future research to understand brain-regional vulnerability in HD.

Coarse woody debris stocks as a function of forest type and stand age in Costa Rican tropical dry forest: long-lasting legacies of previous land use

2010 ◽  
Vol 26 (4) ◽  
pp. 467-471 ◽  
Author(s):  
Lisa B. Kissing ◽  
Jennifer S. Powers
Keyword(s):  
Coarse Woody Debris ◽  
Forest Type ◽  
Woody Debris ◽  
Empirical Studies ◽  
Tropical Dry Forest ◽  
Simulation Models ◽  
Dry Forest ◽  
Stand Age ◽  
Dead Trees ◽  
Ecological Importance

The ecological importance of trees lasts much longer than their life spans. Standing dead trees (snags) and fallen trunks and branches are an important component of above-ground carbon stocks and nutrient reserves, provide habitat for wildlife, and interact with disturbance regimes (e.g. by serving as fuel for fires) (Clark et al. 2002, Harmon et al. 1986, Pyle et al. 2008). Despite these diverse functions, woody debris stocks remain poorly quantified in tropical forests in general (Brown 1997), and in tropical dry forests in particular (Harmon et al. 1995). More empirical studies of the patterns of woody debris and processes that control its dynamics are needed to understand its role in global biogeochemical cycles and for ecosystem simulation models, many of which do not represent coarse woody debris (CWD) as a separate pool (Cornwell et al. 2009).

Biomass partitioning in red pine (Pinus resinosa) along a chronosequence in the Upper Peninsula of Michigan

2007 ◽  
Vol 37 (1) ◽  
pp. 93-102 ◽  
Author(s):  
J S King ◽  
C P Giardina ◽  
K S Pregitzer ◽  
A L Friend
Keyword(s):  
Net Primary Production ◽  
Pinus Resinosa ◽  
Biomass Partitioning ◽  
Red Pine ◽  
Stand Age ◽  
Shoot Biomass ◽  
Stand Development ◽  
Individual Tree ◽  
Coarse Root ◽  
Age Related

Carbon (C) allocation to the perennial coarse-root system of trees contributes to ecosystem C sequestration through formation of long-lived live wood biomass and, following senescence, by providing a large source of nutrient-poor detrital C. Our understanding of the controls on C allocation to coarse-root growth is rudimentary, but it has important implications for projecting belowground net primary production responses to global change. Age-related changes in C allocation to coarse roots represent a critical uncertainty for modeling landscape-scale C storage and cycling. We used a 55 year chronosequence approach with complete above- and below-ground harvests to assess the effects of stand development on biomass partitioning in red pine (Pinus resinosa Ait.), a commercially important pine species. Averaged within site, individual-tree root/shoot ratios were dynamic across stand development, changing from 0.17 at 2-, 3-, and 5-year-old sites, to 0.80 at the 8-year-old site, to 0.29 at the 55-year-old site. The results of our study suggest that a current research challenge is to determine the generality of patterns of root-shoot biomass partitioning through stand development for both coniferous and hardwood forest types, and to document how these patterns change as a function of stand age, tree size, environment, and management.

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