scholarly journals A Review of Climate Signals as Predictors of Long-Term Hydro- Climatic Variability

10.5772/56790 ◽  
2013 ◽  
Author(s):  
Shahab Araghinejad ◽  
Ehsan Meidani
Keyword(s):  
Climatic Variability ◽  
Climate Signals

scholarly journals Effect of ecological and conventional managements on soil enzymatic activities in coffee agroecosystems

2018 ◽  
Vol 48 (4) ◽  
pp. 420-428
Author(s):  
Johana Juliet Caballero Vanegas ◽  
Karen Bibiana Mejía Zambrano ◽  
Lizeth Manuela Avellaneda-Torres
Keyword(s):  
Sustainable Management ◽  
Climatic Variability ◽  
Agricultural Practices ◽  
Enzymatic Activities ◽  
Acid And Alkaline Phosphatase ◽  
Dry Seasons ◽  
Synthetic Fertilizers ◽  
Coffee Agroecosystems ◽  
Alkaline And Acid Phosphatase

ABSTRACT Understanding the impacts of agricultural practices on soil quality indicators, such as enzymatic activities, is of great importance, in order to advance in their diagnosis and sustainable management. This study aimed to evaluate the effect of ecological and conventional agricultural managements on enzymatic activities of a soil under coffee agroecosystems. The enzymatic activities were associated with the biogeochemical cycles of nitrogen (urease and protease), phosphorus (acid and alkaline phosphatase) and carbon (β-glucosidase), during the rainy and dry seasons. Physical-chemical soil proprieties were also assessed and related to resilience scores linked to the climatic variability reported for the areas under study. The activities of urease, alkaline and acid phosphatase and ß-glucosidase were statistically higher in ecological agroecosystems than in conventional ones. This may be attributed to the greater application of organic waste in the ecological environment, as well as to the absence of pesticides and synthetic fertilizers, which allow better conditions for the microbial activity. The resilience scores to the climate variability that showed the highest correlations with the assessed enzymatic activities were: the farmers' knowledge on soil microorganisms, non-use of pesticides and synthetic fertilizers and non-dependence on external supplies. It was concluded that the enzymatic activities are modified by the management systems, being specifically favored by the ecological management. This agroecosystem, in the long term, ensures an efficient use of the soil resources, with a lower degradation and contamination.

Green manure: Alternative to carbon sequestration in a Typic Ustipsamment under semiarid conditions

2018 ◽  
Vol 8 ◽  
Author(s):  
Nelson Virgilio Piraneque Gambasica ◽  
Sonia Esperanza Aguirre Forero ◽  
Adriano Reis Lucheta
Keyword(s):  
Carbon Sequestration ◽  
Cover Crops ◽  
Green Manure ◽  
Block Design ◽  
Climatic Variability ◽  
Plant Cover ◽  
Caribbean Region ◽  
Full Potential ◽  
Semiarid Conditions

Vegetative soil cover mitigates climatic variability and enhances the balance between mineralization and humification processes. Under aerobic conditions, most of the carbon that enters the soil is labile, but a small fraction (1%) is humified and stable, contributing to the soil carbon reserve; therefore, it is important to assess the carbon content captured after green manure cultivation and decomposition. During two consecutive semesters, July to December 2016 and January to June 2017, green manure plots (<em>Zea mays </em>L., <em>Andropogon sorghum </em>subsp.<em> sudanensis </em>and <em>Crotalaria longirostrata</em>) were cultivated individually, in a consortium or amended with palm oil agro-industrial biosolids in a randomized complete block design with 12 treatments. Once decomposed, the different carbon fractions (organic, oxidizable, non-oxidizable, removable and total) were determined. The results showed high total and organic carbon contents under the sorghum treatment, at 30 and 28 Mg ha<sup>-1</sup>, respectively, followed by those under the fallow + biosolid treatment, at 29.8 Mg ha<sup>-1</sup> and 27.5 Mg ha<sup>-1</sup>, respectively. Despite the short experiment duration and the possible contributions of previous management on recalcitrant carbon soil stocks, these findings suggest the importance of maintaining plant cover and utilizing green manure in the Colombian Caribbean region. Long-term experiments may be conducted to confirm the full potential of cover crops on carbon sequestration under tropical semiarid conditions.

scholarly journals Testing Farmers’ Perception of Climate Variability: A Case Study from Kirtipur of Kathmandu Valley

2012 ◽  
pp. 30-34
Author(s):  
Jiban Mani Poudel
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Global Climate ◽  
Climatic Variability ◽  
Global Perspective ◽  
Kathmandu Valley ◽  
Climatic Fluctuations ◽  
Climate Fluctuations ◽  
Global And Local

In the 21st century, global climate change has become a public and political discourse. However, there is still a wide gap between global and local perspectives. The global perspective focuses on climate fluctuations that affect the larger region; and their analysis is based on long-term records over centuries and millennium. By comparison, local peoples’ perspectives vary locally, and local analyses are limited to a few days, years, decades and generations only. This paper examines how farmers in Kirtipur of Kathmandu Valley, Nepal, understand climate variability in their surroundings. The researcher has used a cognized model to understand farmers’ perception on weather fluctuations and climate change. The researcher has documented several eyewitness accounts of farmers about weather fluctuations which they have been observing in a lifetime. The researcher has also used rainfall data from 1970-2009 to test the accuracy of perceptions. Unlike meteorological analyses, farmers recall and their understanding of climatic variability by weather-crop interaction, and events associating with climatic fluctuations and perceptions are shaped by both physical visibility and cultural frame or belief system.DOI: http://dx.doi.org/10.3126/hn.v11i1.7200 Hydro Nepal Special Issue: Conference Proceedings 2012 pp.30-34

scholarly journals On the effect of short-term climate variability on mountain glaciers: insights from a case study

2013 ◽  
Vol 59 (217) ◽  
pp. 992-1006 ◽  
Author(s):  
Daniel Farinotti
Keyword(s):  
Climatic Variability ◽  
Swiss Alps ◽  
Ice Dynamics ◽  
Mountain Glaciers ◽  
Temperature And Precipitation ◽  
Glacier Ice ◽  
Long Term Trends ◽  
Model Set ◽  
Set Up

AbstractStudies addressing the response of glaciers to climate change have so far analyzed the effect of long-term trends in a particular set of meteorological variables only, implicitly assuming an unaltered climatic variability. Here a framework for distinguishing between year-to-year, month-to-month and day-to-day variability is proposed. Synthetically generated temperature and precipitation time series following the same long-term trend but with altered variability are then used to force an ice-dynamics model set up for Rhonegletscher, Swiss Alps. In the case of temperature, variations in the day-to-day variability are shown to have a larger effect than changes at the yearly scale, while in the case of precipitation, variability changes are assessed as having negligible impact. A first set of scenarios is used to show that compared to reference, doubling the temperature variability can reduce glacier ice volume by up to 64% within half a decade. A second set derived from the results of the European ENSEMBLES project, however, shows that such changes are expected to remain below 8% even for extreme scenarios. Although the latter results relativize the importance of the effect in the near future, the analyses indicate that at least caution is required when assuming ‘unchanged variability’.

scholarly journals A climatic dipole drives short- and long-term patterns of postfire forest recovery in the western United States

2020 ◽  
Vol 117 (47) ◽  
pp. 29730-29737
Author(s):  
Caitlin E. Littlefield ◽  
Solomon Z. Dobrowski ◽  
John T. Abatzoglou ◽  
Sean A. Parks ◽  
Kimberley T. Davis
Keyword(s):  
Ponderosa Pine ◽  
Spatial Scales ◽  
Climatic Variability ◽  
Analysis Data ◽  
Forest Recovery ◽  
Regional Patterns ◽  
Northern Rocky Mountains ◽  
Interior West ◽  
Favorable Conditions

Researchers are increasingly examining patterns and drivers of postfire forest recovery amid growing concern that climate change and intensifying fires will trigger ecosystem transformations. Diminished seed availability and postfire drought have emerged as key constraints on conifer recruitment. However, the spatial and temporal extent to which recurring modes of climatic variability shape patterns of postfire recovery remain largely unexplored. Here, we identify a north–south dipole in annual climatic moisture deficit anomalies across the Interior West of the US and characterize its influence on forest recovery from fire. We use annually resolved establishment models from dendrochronological records to correlate this climatic dipole with short-term postfire juvenile recruitment. We also examine longer-term recovery trajectories using Forest Inventory and Analysis data from 989 burned plots. We show that annual postfire ponderosa pine recruitment probabilities in the northern Rocky Mountains (NR) and the southwestern US (SW) track the strength of the dipole, while declining overall due to increasing aridity. This indicates that divergent recovery trajectories may be triggered concurrently across large spatial scales: favorable conditions in the SW can correspond to drought in the NR that inhibits ponderosa pine establishment, and vice versa. The imprint of this climatic dipole is manifest for years postfire, as evidenced by dampened long-term likelihoods of juvenile ponderosa pine presence in areas that experienced postfire drought. These findings underscore the importance of climatic variability at multiple spatiotemporal scales in driving cross-regional patterns of forest recovery and have implications for understanding ecosystem transformations and species range dynamics under global change.

The effects of seasonal and long-term climatic variability on Neotropical flowering phenology: An ecoinformatic analysis of aerial pollen data

2017 ◽  
Vol 41 ◽  
pp. 54-63 ◽  
Author(s):  
Derek S. Haselhorst ◽  
David K. Tcheng ◽  
J. Enrique Moreno ◽  
Surangi W. Punyasena
Keyword(s):  
Climatic Variability ◽  
Flowering Phenology ◽  
Pollen Data

Observed Long-Term Climatic Variability and Its Impacts on the Ground Water Level of Quetta Alluvial

2017 ◽  
Vol 42 (2) ◽  
pp. 589-600 ◽  
Author(s):  
Imran H. Durrani ◽  
Shahzada Adnan ◽  
Maqsood Ahmad ◽  
S. M. Khair ◽  
Ehsanullah Kakar
Keyword(s):  
Ground Water ◽  
Water Level ◽  
Climatic Variability ◽  
Ground Water Level
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