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2022 ◽  
Vol 4 ◽  
Author(s):  
Cristián Frêne ◽  
Mariela Núñez-Ávila ◽  
Ben Castro ◽  
Juan J. Armesto

Rainfall partitioning in secondary forests from southern Chile is relevant in the climate change scenario, in which a 30% reduction in summer precipitation has been projected for the temperate region. Logging and degradation of old-growth forests has resulted in extensive secondary forests, over large areas of the Chiloé Archipelago as well as the mainland. These secondary forests are simple tree communities, dominated by two broad-leaved tree species, evergreen Drimys winteri and Nothofagus nitida, and have the potential to provide multiple benefits to society, including water provision, soil protection, and wood-derived products. Here, we ask how southern South American secondary rainforests modulate rainwater redistribution considering precipitation partitioning. We evaluated the seasonality of throughfall and stemflow components of precipitation, to assess ecohydrological processes for water regulation in a climate change context, where summer droughts have been more frequent in the last decade. The partitioning of gross rainfall (TP) into throughfall (TH), stemflow (ST), and canopy interception (IN) in relation to forest structure, was assessed in four forest plots (400 m2 each) in Senda Darwin Biological Station, Chiloé. TH and ST were measured seasonally for 35 rainfall events from 2019 to 2021. IN water losses were estimated from the mass balance equation. Results indicate that the secondary rainforest intercepts 33% of TP (990 mm of the total monitored), where 59% of the volume corresponds to TH and 7% to ST, which taken together account for nearly 100% the rainwater that reaches the forest floor. Canopy IN varied seasonally from 25 to 40% of total rainfall, with maximum values occurring in the growing season (spring-summer). We found no statistical relation between ST and forest structural parameters (DBH, Basal Area). We explored the contribution of the two dominant tree species to ST and discuss the results in a climate change context. Finally, we propose to incorporate this hydrologic knowledge into adaptive forest management strategies to maximize ecosystem benefits to people. If these ecosystems were properly managed, they have the potential to provide multiple benefits to society within this century, such as water provision and soil protection in addition to carbon sequestration in biomass.


Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 67
Author(s):  
Shivaji Hausrao Thube ◽  
Thava Prakasa Pandian ◽  
Anthara Bhavishya ◽  
Merin Babu ◽  
Arulappan Josephrajkumar ◽  
...  

Xylosandrus crassiusculus (Coleoptera: Curculionidae: Scolytinae) is reported causing damage to areca palm plantations (Areca catechu L.—Arecaceae) in Karnataka (India). In particular, X. crassiusculus has been observed attacking and successfully reproducing on areca nuts; besides the new host plant record, the data provided here represent the first documented case of spermatophagy for this xyleborine beetle. All infestation symptoms of this polyphagous pest were documented and illustrated. The identity of the scolytid, besides morphologically, was confirmed by its DNA barcoding. Eggs, larvae and pupae were found within the galleries of infested kernels. All galleries of the infested kernels were characterized by the presence of whitish to greyish fungal growth. The fungus was identified as Ambrosiella roeperi, a known symbiont of Xylosandrus crassiusculus. Incidence of this symbiotic insect-fungus complex in the economic part of arecanut, i.e., the kernel, is of serious concern. In a climate change scenario, this beetle with fungal symbionts may pose a serious threat to arecanut production in India and elsewhere.


2022 ◽  
Author(s):  
Gilmar Veriato Fluzer Santos ◽  
Lucas Gamalel Cordeiro ◽  
Claudio Antonio Rojo ◽  
Edison Luiz Leismann

Abstract Global warming has divided the scientific community worldwide with predominance for anthropogenic alarmism. This article aims to project a climate change scenario using a stochastic model of paleotemperature time series and compare it with the dominant thesis. The ARIMA model – an integrated autoregressive process of moving averages, known as Box-Jenkins - was used for this purpose. The results showed that the estimates of the model parameters were below 1°C for a scenario of 100 years which suggests a period of temperature reduction and a probable cooling, contrary to the prediction of the IPCC and the anthropogenic current of an increase in 1.50° C to 2.0° C by the end of this century. Thus, we hope with this study to contribute to the discussion by adding a statistical element of paleoclimate in counterpoint to the current consensus and to placing the debate in a long-term historical dimension, in line with other research present in climate sciences and statistics.


Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 98
Author(s):  
Samuel Reis ◽  
Joana Martins ◽  
Fátima Gonçalves ◽  
Cristina Carlos ◽  
João A. Santos

The European grapevine moth (Lobesia botrana; Denis and Schiffermüller, 1775) is considered a key pest for grapevine (Vitis vinifera L.) in the Douro Region, Portugal. The phenology of both the grapevine and the pest has changed in the last decades due to the increase in temperature. Here, we assess the potential impact of climate change on the (a)synchrony of both species. The results show that the phenological stages (budburst, flowering and veraison) undergo an advancement throughout the region (at an ~1 km resolution) under a climate change scenario (Representative Concentration Pathways, RCP8.5) for the period 2051–2080, with respect to the historic period (1989–2015). For cv. Touriga Nacional and Touriga Franca, the budburst advances up to 14 days, whereas for flowering and veraison the advancements are up to 10 days (mainly at low elevations along the Douro River). For the phenology of Lobesia botrana, earliness was also verified in the three flights (consequently there may be more generations per year), covering the entire region. Furthermore, the third flight advances further compared to the others. For both varieties, the interaction between the third flight (beginning and peak) and the veraison date is the most relevant modification under the future climate change scenario (RCP8.5, 2051–2080). The aforementioned outcomes from the phenology models help to better understand the possible shifts of both trophic levels in the region under future climate, giving insights into their future interactions.


MAUSAM ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 229-244
Author(s):  
K. RUPA KUMAR ◽  
R. G. ASHRIT

The regional climatic impacts associated with global climatic change and their assessment are very important since agriculture, water resources, ecology etc., are all vulnerable to climatic changes on regional scale. Coupled Atmosphere-Ocean general circulation model (AOGCM) simulations provide a range of scenarios, which can be used, for the assessment of impacts and development of adaptive or mitigative strategies. Validation of the models against the observations and establishing the sensitivity to climate change forcing are essential before the model projections are used for assessment of possible impacts. Moreover model simulated climate projections are often of coarse resolution while the models used for impact assessment, (e.g. crop simulation models, or river runoff models etc.) operate on a higher spatial resolution. This spatial mismatch can be overcome by adopting an appropriate strategy of downscaling the GCM output.   This study examines two AOGCM (ECHAM4/OPYC3 and HadCM2) climate change simulations for their performance in the simulation of monsoon climate over India and the sensitivity of the simulated monsoon climate to transient changes in the atmospheric concentrations of greenhouse gases and sulfate aerosols. The results show that the two models simulate the gross features of climate over India reasonably well. However the inter-model differences in simulation of mean characteristics, sensitivity to forcing and in the simulation of climate change suggest need for caution. Further an empirical downscaling approach in used to assess the possibility of using GCM projections for preparation of regional climate change scenario for India.


Author(s):  
Claudinei Oliveira-Santos ◽  
Vinicius Vieira Mesquita ◽  
Leandro Leal Parente ◽  
Alexandre de Siqueira Pinto ◽  
Laerte Guimaraes Ferreira

The Brazilian livestock is predominantly extensive, with approximately 90% of the production being sustained on pasture, which occupies around 20% of the territory. In the current climate change scenario and where cropland is becoming a limited resource, there is a growing need for a more efficient land use and occupation. It is estimated that more than half of the Brazilian pastures have some level of degradation; however there is still no mapping of the quality of pastures on a national scale. In this study, we mapped and evaluated the spatio-temporal dynamics of pasture quality in Brazil, between 2010 and 2018, considering three classes of degradation: Absent (D0), Intermediate (D1), and Severe (D2). There was no variation in the total area occupied by pastures in the evaluated period, in spite of the accentuated spatial dynamics, with a retraction in the center-south and expansion to the north, over areas of ​​native vegetation. The percentage of non-degraded pastures increased ~12%, due to the recovery of degraded areas and the emergence of new pasture areas as a result of the prevailing spatial dynamics. However, about 44 Mha of the pasture area is currently severely degraded. The dynamics in pasture quality were not homogeneous in property size classes. We observed that in the approximately 2.68 million properties with livestock activity, the proportion with quality gains was twice as low in small properties compared to large ones, and the proportion with losses was three times greater, showing an increase in inequality between properties with more and less resources (large and small, respectively). The areas occupied by pastures in Brazil present an unique opportunity to increase livestock production and make available areas for agriculture, without the need for new deforestation in the coming decades.


MAUSAM ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 263-274
Author(s):  
L. S. RATHORE ◽  
K. K. SINGH ◽  
S. A. SASEENDRAN ◽  
A. K. BAXLA

The CERES-Rice crop simulation model, calibrated and validated for the    varieties PR106 in NW India. IR36 in central India and Jaya in south India, is used for  nalysing the effect of climate change on rice productivity in the country. Plausible climate change scenario for the Indian subcontinent as expected by the middle of the next century taking into account the projected emissions of greenhouse gases and sulphate aerosols, in a coupled atmosphere-ocean model experiment performed at Deutsches Klimarechenzentrum, Germany, is adopted for the study. The adopted scenario represented an increase in monsoon seasonal mean surface temperature of the order of about 1.5° C over the south India and 1°C over northwest and central India in the decade 2040-49 with respect to the 1980s and an increase in rainfall of the order of 2 mm per day over south India while the simulated decrease of the order about -1 mm and -1.5 mm over northwest and central India respectively. The IPCC Business-as-usual scenario projection of plant usable concentration of CO2 about 460 PPM by the middle fo the next century are also used in the crop model simulation (CERES - Rice V3 Model).   Simulation studies carried out with the climate change scenarios over different parts of the country are analysed and interpreted.


2021 ◽  
Author(s):  
Tosca van Gelderen ◽  
Jerome Montfort ◽  
José Antonio Álvarez-Diós ◽  
Violette Thermes ◽  
Francesc Piferrer ◽  
...  

MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression in a wide variety of physiological processes, including those related to the reproductive system. Although in the last decade a plethora of miRNAs has been reported, the miRNA alterations occurred by environmental cues and their biological functions have not yet been elucidated. With the aim to identify epigenetic regulations mediated by miRNAs in the gonads in a climate change scenario, zebrafish (Danio rerio) were subjected to high temperatures during sex differentiation (18-32 days post fertilization, dpf), a treatment that results in male-skewed sex ratios. Once the fish reached adulthood (90 dpf), ovaries and testes were sequenced by high-throughput technologies. About 101 million high-quality reads were obtained from gonadal samples. Analyses of the expression levels of the miRNAs identified a total of 23 and 1 differentially expressed (DE) miRNAs in ovaries and testes, respectively, two months after the heat treatment. Most of the identified miRNAs were involved in human sex-related cancer. After retrieving 3’ UTR regions, ~400 predicted targets of the 24 DE miRNAs were obtained, some with reproduction-related functions. Their synteny in the zebrafish genome was, for more than half of them, in the chromosomes 7, 2, 4, 3 and 11 in the ovaries, chromosome 4 being the place where the predicted sex-associated-region (sar) is localized in wild zebrafish. Further, spatial localization in the gonads of two selected miRNAs (miR-122-5p and miR-146-5p) showed exclusive expression in the ovarian germ cells. The present study expands the catalog of sex-specific miRNAs and deciphers, for the first time, thermosensitive miRNAs in the zebrafish gonads that might be used as potential epimarkers to predict environmental past events.


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