scholarly journals Community specific hydraulic conductance potential of soil water decomposed for two Alpine grasslands by small-scale lysimetry

2017 ◽  
Author(s):  
Georg Frenck ◽  
Georg Leitinger ◽  
Nikolaus Obojes ◽  
Magdalena Hofmann ◽  
Christian Newesely ◽  
...  
Keyword(s):  
Soil Water ◽  
Potential Evapotranspiration ◽  
Vegetation Type ◽  
Biomass Productivity ◽  
High Water ◽  
Small Scale ◽  
Alpine Grasslands ◽  
Vegetation Development ◽  
Water Conductance ◽  
Extreme Precipitation Events

Abstract. For Central Europe in addition to rising temperatures an increasing variability of precipitation is predicted. This will increase the probability of drought periods in the Alps, where water supply has been sufficient in most areas so far. For Alpine grasslands, community specific imprints on drought response are merely understood. In a replicated mesocosm experiment we compared evapotranspiration and biomass productivity of two differently drought-adapted vegetation communities during two artificial drought periods divided by extreme precipitation events using high precision small lysimeters. The drought adapted vegetation type showed a high potential to utilize even scarce water resources combined with a low potential to translate atmospheric deficits into higher water conductance with biomass production staying below those measured for the non-drought-adapted type. The non-drought-adapted type, in contrast, showed high water conductance potential with strongly increasing ET rates when environmental conditions became less constraining. With high rates even at dry conditions, this community appears not to be optimized to save water and might experience drought effects earlier and probably stronger. In summary, the vegetation’s reaction two co-varying gradients of potential evapotranspiration and soil water content revealed a clear difference of vegetation development and between water-saving and water-spending strategies regarding evapotranspiration.

scholarly journals Community-specific hydraulic conductance potential of soil water decomposed for two Alpine grasslands by small-scale lysimetry

2018 ◽  
Vol 15 (4) ◽  
pp. 1065-1078 ◽  
Author(s):  
Georg Frenck ◽  
Georg Leitinger ◽  
Nikolaus Obojes ◽  
Magdalena Hofmann ◽  
Christian Newesely ◽  
...  
Keyword(s):  
Water Supply ◽  
Soil Water ◽  
Plant Community ◽  
Potential Evapotranspiration ◽  
Vegetation Type ◽  
Strong Increase ◽  
Small Scale ◽  
Alpine Grasslands ◽  
Water Conductance ◽  
Extreme Precipitation Events

Abstract. For central Europe in addition to rising temperatures an increasing variability in precipitation is predicted. This will increase the probability of drought periods in the Alps, where water supply has been sufficient in most areas so far. For Alpine grasslands, community-specific imprints on drought responses are poorly analyzed so far due to the sufficient natural water supply. In a replicated mesocosm experiment we compared evapotranspiration (ET) and biomass productivity of two differently drought-adapted Alpine grassland communities during two artificial drought periods divided by extreme precipitation events using high-precision small lysimeters. The drought-adapted vegetation type showed a high potential to utilize even scarce water resources. This is combined with a low potential to translate atmospheric deficits into higher water conductance and a lower biomass production as those measured for the non-drought-adapted type. The non-drought-adapted type, in contrast, showed high water conductance potential and a strong increase in ET rates when environmental conditions became less constraining. With high rates even at dry conditions, this community appears not to be optimized to save water and might experience drought effects earlier and probably more strongly. As a result, the water use efficiency of the drought-adapted plant community is with 2.6 gDW kg−1 of water much higher than that of the non-drought-adapted plant community (0.16 gDW kg−1). In summary, the vegetation's reaction to two covarying gradients of potential evapotranspiration and soil water content revealed a clear difference in vegetation development and between water-saving and water-spending strategies regarding evapotranspiration.

scholarly journals Growth of Haematococcus pluvialis on a Small-Scale Angled Porous Substrate Photobioreactor for Green Stage Biomass

2021 ◽  
Vol 11 (4) ◽  
pp. 1788
Author(s):  
Thanh-Tri Do ◽  
Binh-Nguyen Ong ◽  
Tuan-Loc Le ◽  
Thanh-Cong Nguyen ◽  
Bich-Huy Tran-Thi ◽  
...  
Keyword(s):  
Light Intensity ◽  
Algal Biomass ◽  
Haematococcus Pluvialis ◽  
Biomass Productivity ◽  
Pilot Scale ◽  
Small Scale ◽  
Porous Substrate ◽  
Low Light ◽  
Green Algal ◽  
Green Stage

In the production of astaxanthin from Haematococcus pluvialis, the process of growing algal biomass in the vegetative green stage is an indispensable step in both suspended and immobilized cultivations. The green algal biomass is usually cultured in a suspension under a low light intensity. However, for astaxanthin accumulation, the microalgae need to be centrifuged and transferred to a new medium or culture system, a significant difficulty when upscaling astaxanthin production. In this research, a small-scale angled twin-layer porous substrate photobioreactor (TL-PSBR) was used to cultivate green stage biomass of H. pluvialis. Under low light intensities of 20–80 µmol photons m−2·s−1, algae in the biofilm consisted exclusively of non-motile vegetative cells (green palmella cells) after ten days of culturing. The optimal initial biomass density was 6.5 g·m−2, and the dry biomass productivity at a light intensity of 80 µmol photons m−2·s−1 was 6.5 g·m−2·d−1. The green stage biomass of H. pluvialis created in this small-scale angled TL-PSBR can be easily harvested and directly used as the source of material for the inoculation of a pilot-scale TL-PSBR for the production of astaxanthin.

scholarly journals A MODEL FOR ESTIMATING ACTUAL EVAPOTRANSPIRATION FROM POTENTIAL EVAPOTRANSPIRATION

1975 ◽  
Vol 6 (3) ◽  
pp. 170-188 ◽  
Author(s):  
K. J. KRISTENSEN ◽  
S. E. JENSEN
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Root Zone ◽  
Potential Evapotranspiration ◽  
Actual Evapotranspiration ◽  
Vegetation Density ◽  
Rainfall Distribution ◽  
Sugar Beets

A model for calculating the daily actual evapotranspiration based on the potential one is presented. The potential evapotranspiration is reduced according to vegetation density, water content in the root zone, and the rainfall distribution. The model is tested by comparing measured (EAm) and calculated (EAc) evapotranspirations from barley, fodder sugar beets, and grass over a four year period. The measured and calculated values agree within 10 %. The model also yields information on soil water content and runoff from the root zone.

scholarly journals Multivariate ordination identifies vegetation types associated with spider conservation in brassica crops

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3795 ◽  
Author(s):  
Hafiz Sohaib Ahmed Saqib ◽  
Minsheng You ◽  
Geoff M. Gurr
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Vegetation Type ◽  
Unmet Need ◽  
Conservation Biological Control ◽  
Small Scale ◽  
Brassica Crops ◽  
Multivariate Ordination ◽  
Southern Chinese ◽  
Brassica Crop

Conservation biological control emphasizes natural and other non-crop vegetation as a source of natural enemies to focal crops. There is an unmet need for better methods to identify the types of vegetation that are optimal to support specific natural enemies that may colonize the crops. Here we explore the commonality of the spider assemblage—considering abundance and diversity (H)—in brassica crops with that of adjacent non-crop and non-brassica crop vegetation. We employ spatial-based multivariate ordination approaches, hierarchical clustering and spatial eigenvector analysis. The small-scale mixed cropping and high disturbance frequency of southern Chinese vegetation farming offered a setting to test the role of alternate vegetation for spider conservation. Our findings indicate that spider families differ markedly in occurrence with respect to vegetation type. Grassy field margins, non-crop vegetation, taro and sweetpotato harbour spider morphospecies and functional groups that are also present in brassica crops. In contrast, pumpkin and litchi contain spiders not found in brassicas, and so may have little benefit for conservation biological control services for brassicas. Our findings also illustrate the utility of advanced statistical approaches for identifying spatial relationships between natural enemies and the land uses most likely to offer alternative habitats for conservation biological control efforts that generates testable hypotheses for future studies.

scholarly journals Is Cut-Flower Industry Promotion by the Government Negatively Affecting Pollinator Biodiversity and Environmental/Human Health in Uganda?

2014 ◽  
Vol 2014 ◽  
pp. 1-52
Author(s):  
Bin Mushambanyi Théodore Munyuli
Keyword(s):  
Human Health ◽  
Crop Production ◽  
Vegetation Type ◽  
Primary Data ◽  
Small Scale ◽  
Pollination Services ◽  
Toxicological Studies ◽  
The Government ◽  
Small Scale Farmers ◽  
The Impact

A study was conducted from 2010 to 2012 around the flower growing areas in central Uganda to generate baseline information on the status of pollinators. Primary data were gathered using a questionnaire that aimed at determining farmers and flower farm officials’ perceptions on the impact of activities carried out inside greenhouses on pollinators, human health, and on crop production in the surroundings. Results indicated that the quantity of pesticides and fertilizers applied daily varied among the different flower farms visited. Bee species richness and abundance varied significantly (P<0.01) according to flower farm location, to the landscape vegetation type, and to field types found in the surrounding of flower farms. Bee richness found around flower farms varied in number from 20 to 40 species in total across seasons and years. Bee density increased significantly with the increase in flower density. Small-scale farmers were aware of the value and importance of pollination services in their farming business. There was no clear evidence of a direct effect of agrochemicals application on bee communities living in the surrounding habitats. There is a need for further research to be conducted on human health risks and for toxicological studies on soils, plants, flowers, and bees in the farm landscape.

scholarly journals Summer drought in Switzerland 1981‒2020: Events, trends and drivers

2021 ◽  
Author(s):  
Simon C. Scherrer ◽  
Christoph Spirig ◽  
Martin Hirschi ◽  
Felix Maurer ◽  
Sven Kotlarski
Keyword(s):  
Regional Climate Model ◽  
Soil Water ◽  
Climate Model ◽  
Potential Evapotranspiration ◽  
Meteorological Data ◽  
Regional Climate ◽  
Reanalysis Data ◽  
Summer Drought ◽  
Temperature And Precipitation ◽  
Temperature Scaling

&lt;p&gt;The Alpine region has recently experienced several dry summers with negative impacts on the economy, society and ecology. Here, soil water, evapotranspiration and meteorological data from several observational and model-based data sources is used to assess events, trends and drivers of summer drought in Switzerland in the period 1981&amp;#8210;2020. 2003 and 2018 are identified as the driest summers followed by somewhat weaker drought conditions in 2020, 2015 and 2011. We find clear evidence for an increasing summer drying in Switzerland. The observed climatic water balance (-39.2&amp;#160;mm/decade) and 0-1 m soil water from reanalysis (ERA5-Land: -4.7&amp;#160;mm/decade; ERA5: -7.2&amp;#160;mm/decade) show a clear tendency towards summer drying with decreasing trends in most months. Increasing evapotranspiration (potential evapotranspiration: +21.0&amp;#160;mm/decade; ERA5-Land actual evapotranspiration: +15.1&amp;#160;mm/decade) is identified as important driver which scales excellently (+4 to +7%/K) with the observed strong warming of about 2&amp;#176;C. An insignificant decrease in precipitation further enhanced the tendency towards drier conditions. Most simulations of the EURO-CORDEX regional climate model ensemble underestimate the changes in summer drying. They underestimate both, the observed recent summer warming and the small decrease in precipitation. The changes in temperature and precipitation are negatively correlated, i.e. simulations with stronger warming tend to show (weak) decreases in precipitation. However, most simulations and the reanalysis overestimate the correlation between temperature and precipitation and the precipitation-temperature scaling on the interannual time scale. Our results emphasize that the analysis of the regional summer drought evolution and its drivers remains challenging especially with regional climate model data but considerable uncertainties also exist in reanalysis data sets.&lt;/p&gt;

scholarly journals The course, stratification and possibility of simulating relative air humidity in winter wheat stand

2016 ◽  
Vol 46 (2) ◽  
pp. 137-154
Author(s):  
Jana Krčmářová ◽  
Radovan Pokorný ◽  
Tomáš Středa
Keyword(s):  
Regression Analysis ◽  
Winter Wheat ◽  
Soil Water ◽  
Potential Evapotranspiration ◽  
Soil Water Potential ◽  
Air Humidity ◽  
Field Station ◽  
Effective Height ◽  
Relative Air Humidity ◽  
Climatological Station

AbstractThe aim of this study was: (i) long-term (2010, 2011 and 2013) evaluation of the relative air humidity in the winter wheat canopy, (ii) finding of relationships between relative air humidity in canopy and computed or measured meteorological values (precipitation totals, evapotranspiration, moisture balance, specific air humidity, volume soil moisture, % of available soil water content, value of soil water potential), (iii) testing of simulation of daily relative air humidity, based on selected meteorological values and potential evapotranspiration (FAO Penman-Monteith method) and actual evapotranspiration, (iv) testing of simulation of relative air humidity hourly values in the wheat canopy, (v) evaluation of dependence between relative air humidity and leaf wetness. The measurement was performed at the experimental field station of Mendel University in Žabčice (South Moravia, the Czech Republic). Data recording for wheat canopy was conducted by means of a meteostation equipped with digital air humidity and air temperature sensors positioned in the ground, effective height of the stand and in 2 m above the ground. The main vegetation period of wheat was divided into three stages to evaluate differences in various growing phases of wheat. The data from nearby standard climatological stations and from agrometeorological station in Žabčice were used for establishment of relationships between relative air humidity in winter wheat canopy and surrounding environment by correlation and regression analysis. Relative air humidity above 90% occurred substantially longer on the ground and at the effective height of the stand in comparison with the height of 2 m. By means of regression analysis we determined that the limit of 90% was reached in the canopy when at the climatological station it was just 60 to 90% for ground level and 70 to 90% for effective height, especially during the night. Slight dependence between measured or computed meteorological variables and relative air humidity in winter wheat canopy was found (r= 0.23 − 0.56 for precipitation totals,r= 0.27 − 0.57 for % of available soil water capacity, etc.). The simulation of hourly values of relative air humidity in wheat canopy is partially possible just when using the data of relative air humidity from the relevant standard climatological station.

scholarly journals Monitoring Water‐Soil Dynamics and Tree Survival Using Soil Sensors under a Big Data Approach

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4634
Author(s):  
Pascual ◽  
Rivera ◽  
Gómez ◽  
Domínguez-Lerena
Keyword(s):  
Big Data ◽  
Soil Water ◽  
Real Time ◽  
Water Dynamics ◽  
Species Selection ◽  
Soil Dynamics ◽  
Small Scale ◽  
Soil Water Dynamics ◽  
Soil Sensors ◽  
Tree Survival

The high importance of green urban planning to ensure access to green areas requires modern and multi-source decision-support tools. The integration of remote sensing data and sensor developments can contribute to the improvement of decision-making in urban forestry. This study proposes a novel big data-based methodology that combines real-time information from soil sensors and climate data to monitor the establishment of a new urban forest in semi-arid conditions. Water‐soil dynamics and their implication in tree survival were analyzed considering the application of different treatment restoration techniques oriented to facilitate the recovery of tree and shrub vegetation in the degraded area. The synchronized data-capturing scheme made it possible to evaluate hourly, daily, and seasonal changes in soil‐water dynamics. The spatial variation of soil‐water dynamics was captured by the sensors and it highly contributed to the explanation of the observed ground measurements on tree survival. The methodology showed how the efficiency of treatments varied depending on species selection and across the experimental design. The use of retainers for improving soil moisture content and adjusting tree-watering needs was, on average, the most successful restoration technique. The results and the applied calibration of the sensor technology highlighted the random behavior of water‐soil dynamics despite the small-scale scope of the experiment. The results showed the potential of this methodology to assess watering needs and adjust watering resources to the vegetation status using real-time atmospheric and soil data.

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