scholarly journals TREE SPECIES SUSCEPTIBILITY TO LEAF-CUTTING ANTS ATTACK IN CARBON NEUTRALIZATION PLANTATIONS

Nativa ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 567-572
Author(s):  
Vicente Toledo Machado de Morais Júnior ◽  
Laércio Antônio Gonçalves Jacovine ◽  
Mateus Comine Frades da Silva ◽  
Bruno Leão Said Schettini ◽  
Maria Paula Miranda Xavier Rufino ◽  
...  

Greenhouse gas (GHG) emissions neutralize planting are one of the options for climate changes mitigating. Leaf-cutter ants attack is a threat to the plantations proper development. Ants have selective foraging, which makes it important to know this selectivity and, thus, choose more suitable species to neutralization planting compose. Thus, the goal of the present study was to evaluate the tree species susceptibility to be attacked by leaf-cutter ants in carbon neutralization plantations. The study was carried out in mixed plantations in Viçosa-MG and a classification was created for the present species. The Damage Index (DI) was created by multiplying the Mean of Severity (MS) and the Frequency of Attacks (FA). The species were classified according to the indication for neutralization plantations (indicated, moderately indicated, and not indicated) and potential species for the extraction of natural insecticides. From the 59 species evaluated, 22 were classified as suitable for neutralization plantations, 6 as moderately indicated, 24 as not indicated, and 7 as potential species for extracting natural insecticides. Keywords: forest carbon; pest control; carbon offset; mixed plantings.

Radiocarbon ◽  
2018 ◽  
Vol 60 (5) ◽  
pp. 1301-1315 ◽  
Author(s):  
Tünde Törőcsik ◽  
Sándor Gulyás ◽  
Dávid Molnár ◽  
Réka Tapody ◽  
Balázs P Sümegi ◽  
...  

ABSTRACTThis paper presents first chronological results for a Holocene marshland system from the southern part of the Danube-Tisza Interfluve. Radiocarbon (14C) ages were used to build age-depth models relying of probabilistic tools. Four models have been built: a linear one using dates gained via simple calibration, a P_Sequence model, fitting a polynomial function to calibrated dates; a Gamma_Sequence considering priori given and posterior accumulation rates have been constructed. As there was no significant difference between the mean values of individual models all seem suitable for establishing a reliable chronology despite differences in 95% CI ranges. While P_Sequence models underestimated SR, values calculated from the polynomial model were not significantly different from those of the G_Sequence. Based on multiproxy geochemical, sedimentological, paleoecological data the evolution of the system was reconstructed, covering a timespan of ca. 13,000 years starting from 12,000 BC and lasting until 1300 AD. Highest accumulation rates are dated to the Early Middle Ages from the 11th century. Several climate changes could have been identified which are present in other Hungarian and Western European records too, such as the 5b IRD event at ca. 5800 BC, a humid phase around 1600 BC, and a cool humid phase around the 6th century AD.


Wood Research ◽  
2021 ◽  
Vol 66 (5) ◽  
pp. 746-761
Author(s):  
JIANGTAO SHI ◽  
JUNYI PENG ◽  
CHONGYANG XIA ◽  
JIAN LI

Four coniferous and four deciduous commercial tree species from Northeastern ofChina were selected to investigate the differences ofmetabolites in wood-forming tissues bygas chromatography-mass spectrometry. The results showed that the identified metabolites mainly consisted of neutral sugars, lipids, and organic acids. The mean contents of both arabinofuranose and 1-cyclohexene-1-carboxylic acid were higher in coniferous trees thanin deciduous ones. Similarly, the D-fructose and D-glucose content was significantly higherin coniferous trees than deciduous trees, but the total contents of these two sugars was roughly equal among most tree species. The mean content of lactic acid, glycerol and malic acid was lowerin coniferous trees than deciduous trees. The malic acid content decreased in later-stages of wood formation than in early-stagefor all tree species. The content of L-proline and myo-inositol was greater in later-stage of wood formation than early-stage.The contentof octadecanoic acid, D-fructose and D-glucose decreased in later-stage of wood formationfor most tree species. All of thissuggested that the metabolites in wood-forming tissues showed the significance of species-specific and seasonal dynamic differences among the eight tree species.


2020 ◽  
Author(s):  
Tina Tiller ◽  
Christian Schott

<p>While it is now widely accepted by scientists and governments that human activity contributes to climate change, there is a lack of understanding whether this realisation is now gaining greater attraction with the general public than it had 5 or 10 years ago. Additional gaps in knowledge relate to the link between awareness and action, which could be hypothesised to have become stronger in light of evidence being produced of some projected climate changes occurring already. This article examines climate change awareness and the link with travel-related decision-making by adopting an under-utilised origin perspective in Wellington, New Zealand. The findings, generated by a household mail survey, indicate that the majority of the respondents are aware of tourism’s contribution to climate change and think that it is likely that their lives in New Zealand will be negatively affected by climate change. However, when examining the respondents’ recent holiday decision-making, it is evident that for the overwhelming majority, climate change awareness does not appear to influence travel-related decisions. This article concludes by discussing demand-focused measures aimed at reducing the GHG emissions generated by tourism.</p>


1989 ◽  
Vol 12 (2) ◽  
pp. 55
Author(s):  
R.W. Braithwaite

The location of shelter used by nine species of small mammals released after capture during a mark-recapture study in tropical woodland and open forest was recorded whenever possible. A quantitative profile of such post-release behaviour by different species permits its incorporation into analyses of habitat selection. Characteristics of post-release behaviour also provide clues about the nature of predation pressure on various species. Arboreal species tended to select tree species with boles having camouflage potential. Small species used small holes. Scansorial species used the greatest range of sheltering sites. Average distance moved to shelter was inversely related to the mean density of a species.


Lupus ◽  
2020 ◽  
Vol 29 (13) ◽  
pp. 1781-1789
Author(s):  
Suhas K Ganguli ◽  
Joyce S Hui-Yuen ◽  
Meenakshi Jolly ◽  
Jane Cerise ◽  
Barbara Anne Eberhard

Objective To evaluate the reliability, validity, feasibility and psychometric performance of the Lupus Impact Tracker (LIT) as a patient reported outcome (PRO) measure tool in pediatric systemic lupus erythematosus (pSLE). Methods This is a prospective, observational, pilot study where patients aged between 12 and 25 years, fulfilling the 1997 ACR classification criteria for SLE, were enrolled. Over 3 consecutive, routine, clinical visits, the patients completed the LIT alongside the Patient-Reported Outcomes Measurement Information System-Short Forms (PROMIS-SFs), Childhood Health Assessment Questionnaire (CHAQ). Rheumatologists completed the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC-ACR) Damage Index. Demographic, clinical and laboratory data were also collected. Results Of 46 patients enrolled, 38 patients completed 2 visits and 31 completed all 3 visits. Seventy-eight percent were female, 33% African American, 28% Asian, 15% Caucasian and 17% Hispanic. The mean (SD) age was 17.2 (2.7) years, with a mean (SD) disease duration of 4.6 (3.1) years. The mean (SD) SLEDAI-2K at enrollment was 3.54 (2.96). In the 38 patients who completed two or more visits, intra-class correlation coefficient and Cronbach alpha were calculated to be 0.70 and 0.91 respectively, signifying good reliability of LIT. The LIT showed positive correlation with CHAQ-Disability Index and majority of the PROMIS-SFs parameters. Construct validity was established against clinical disease activity (SLEDAI-2K). Conclusion The preliminary results indicate that the LIT is a reliable and valid instrument to capture PRO in p-SLE. Prospective validation with a larger, multicenter cohort is the next step.


1991 ◽  
Vol 69 (6) ◽  
pp. 1530-1533 ◽  
Author(s):  
Dave Shutler ◽  
Adele Mullie

In a Costa Rican forest adjacent to cattle pasture, larger individuals of the leaf-cutting ant Atta colombica carried heavier loads and foraged farther from the colony, as predicted by foraging theory. Counter to foraging theory, individual ants did not increase their load mass if they foraged farther from the colony. However, the colony avoided this apparent inefficiency by sending larger ants to more distant trees. The colony harvested simultaneously from several individuals of the same tree species, even though distant trees were twice as far from the colony as nearby trees. The reasons for this behaviour require further investigation. In a wide foraging trail, larger ants travelled faster than their smaller counterparts. In addition, ant velocity was reduced when loads were experimentally supplemented, and increased when loads were experimentally reduced. Ants using narrow trails in the leaf litter may all be constrained to travel at the same speed, irrespective of load or body size, simply because they get in each other's way.


2020 ◽  
Vol 2020 ◽  
pp. 1-23
Author(s):  
Sahar Mohammadzadeh Osalu ◽  
Hamzeh Shakib

In this research, the probabilistic seismic performance of asymmetric reinforced concrete wall-frame buildings with different strength distributions incorporating foundation flexibility effects is examined. By using probability-based performance evaluation approach, it is possible to provide a more accurate prediction of the different strength distribution effect on the seismic performance of asymmetric buildings and find the most efficient strength distribution for meeting each performance level. These efficient distributions can be adopted in the performance-based design of asymmetric buildings. For this purpose, first, the regression analysis and the concepts of efficiency and sufficiency were used to determine an optimal intensity measure (IM) for incremental dynamic analysis and evaluating the seismic response of the considered building models. Then, the proper magnitude of interstory drift capacity for this type of buildings in each limit state was estimated using the damage index concept. Finally, the effects of different strength distributions and the flexibility of foundation were studied on the seismic performance of the asymmetric buildings by investigating the mean annual frequencies of exceeding structural performance levels and confidence levels to satisfy performance objectives. It is concluded that irregular distributions of stiffness and strength in the plan of a building highly affect the seismic performance of buildings. Also, the results show that the optimum strength distribution is a function of the objective performance level and these optimum strength distributions are the same for both fixed- and flexible-base conditions. Meanwhile, the flexible effect of foundation increases the mean annual frequencies of exceedance within the range of 10% to 45% and significantly decreases the confidence levels in most cases.


2019 ◽  
Vol 156 (3) ◽  
pp. 299-314 ◽  
Author(s):  
Gabriel Rondeau-Genesse ◽  
Marco Braun

Abstract The pace of climate change can have a direct impact on the efforts required to adapt. For short timescales, however, this pace can be masked by internal variability (IV). Over a few decades, this can cause climate change effects to exceed what would be expected from the greenhouse gas (GHG) emissions alone or, to the contrary, cause slowdowns or even hiatuses. This phenomenon is difficult to explore using ensembles such as CMIP5, which are composed of multiple climate models and thus combine both IV and inter-model differences. This study instead uses CanESM2-LE and CESM-LE, two state-of-the-art large ensembles (LE) that comprise multiple realizations from a single climate model and a single GHG emission scenario, to quantify the relationship between IV and climate change over the next decades in Canada and the USA. The mean annual temperature and the 3-day maximum and minimum temperatures are assessed. Results indicate that under the RCP8.5, temperatures within most of the individual large ensemble members will increase in a roughly linear manner between 2021 and 2060. However, members of the large ensembles in which a slowdown of warming is found during the 2021–2040 period are two to five times more likely to experience a period of very fast warming in the following decades. The opposite scenario, where the changes expected by 2050 would occur early because of IV, remains fairly uncommon for the mean annual temperature, but occurs in 5 to 15% of the large ensemble members for the temperature extremes.


1996 ◽  
Vol 80 (3) ◽  
pp. 521-530 ◽  
Author(s):  
Patricia J. Folgarait ◽  
Lee A. Dyer ◽  
Robert J. Marquis ◽  
H. Elizabeth Braker

1996 ◽  
Vol 86 (3) ◽  
pp. 253-256 ◽  
Author(s):  
Maria José A. Hebling ◽  
Paulo Sérgio Maroti ◽  
Odair Correa Bueno ◽  
Osvaldo Aulino da Silva ◽  
Fernando Carlos Pagnocca

AbstractLaboratory nests of the leaf-cutting ant Atta sexdens rubropilosa Forel fed daily with leaves of Ricinus communis showed a gradual decrease in fungal garden volume, a higher ant mortality rate, and fungal garden extinction after 6 weeks. The mean oxygen consumption rate of these ants was higher than that of control ants collected from nests fed with leaves of Eucalyptus alba (Myrtaceae) suggesting one or more components of the leaves of R. communis had a direct physiological effect on the ants, in addition to inhibiting fungal garden growth.


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