scholarly journals Assessing Forest Level Response to the Death of a Dominant Tree within a Premontane Tropical Rainforest

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1041
Author(s):  
Manuel R. Flores ◽  
Luiza Maria Teophilo Aparecido ◽  
Gretchen R. Miller ◽  
Georgianne W. Moore
Keyword(s):  
Tropical Forests ◽  
Water Use ◽  
Tree Mortality ◽  
Tree Canopy ◽  
Thermal Dissipation ◽  
Small Scale ◽  
Forest Plot ◽  
Water Usage ◽  
Understory Trees ◽  
Treefall Gap

Small-scale treefall gaps are among the most important forms of forest disturbance in tropical forests. These gaps expose surrounding trees to more light, promoting rapid growth of understory plants. However, the effects of such small-scale disturbances on the distribution of plant water use across tree canopy levels are less known. To address this, we explored plant transpiration response to the death of a large emergent tree, Mortoniodendron anisophyllum Standl. & Steyerm (DBH > 220 cm; height ~40 m). Three suppressed, four mid-story, and two subdominant trees were selected within a 50 × 44 m premontane tropical forest plot at the Texas A&M Soltis Center for Research and Education located in Costa Rica. We compared water use rates of the selected trees before (2015) and after (2019) the tree gap using thermal dissipation sap flow sensors. Hemispherical photography indicated a 40% increase in gap fraction as a result of changes in canopy structure after the treefall gap. Micrometeorological differences (e.g., air temperature, relative humidity, and vapor pressure deficit (VPD)) could not explain the observed trends. Rather, light penetration, as measured by sensors within the canopy, increased significantly in 2019. One year after the tree fell, the water usage of trees across all canopy levels increased modestly (15%). Moreover, average water usage by understory trees increased by 36%, possibly as a result of the treefall gap, exceeding even that of overstory trees. These observations suggest the possible reallocation of water use between overstory and understory trees in response to the emergent tree death. With increasing global temperatures and shifting rainfall patterns increasing the likelihood of tree mortality in tropical forests, there is a greater need to enhance our understanding of treefall disturbances that have the potential to redistribute resources within forests.

scholarly journals Forest dynamics of a subtropical monsoon forest in Dinghushan, China: recruitment, mortality and the pace of community change

2013 ◽  
Vol 29 (2) ◽  
pp. 131-145 ◽  
Author(s):  
Yong Shen ◽  
Louis S. Santiago ◽  
Lei Ma ◽  
Guo-Jun Lin ◽  
Ju-Yu Lian ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Forest Dynamics ◽  
Tree Mortality ◽  
Population Change ◽  
Interspecific Interactions ◽  
Community Change ◽  
Subtropical Forest ◽  
Size Class ◽  
Forest Plot ◽  
Monsoon Forest

Abstract:Structure and demographics in many tropical forests is changing, but the causes of these changes remain unclear. We studied 5 y (2005–2010) of species turnover, recruitment, mortality and population change data from a 20-ha subtropical forest plot in Dinghushan, China, to identify trends in forest change, and to test whether tree mortality is associated with intraspecific or interspecific competition. We found the Dinghushan forest to be more dynamic than one temperate and two tropical forests in a comparison of large, long-term forest dynamics plots. Within Dinghushan, size-class distributions were bell-shaped only for the three most dominant species and reverse J-shaped for other species. Bell-shaped population distributions can indicate a population in decline, but our data suggest that these large and long-lived species are not in decline because the pattern is driven by increasing probabilities of transition to larger size class with increasing size and fast growth in saplings. Spatially aggregated tree species distributions were common for surviving and dead individuals. Competitive associations were more frequently intraspecific than interspecific. The competition that induced tree mortality was more associated with intraspecific than interspecific interactions. Intraspecific competitive exclusion and density-dependence appear to play important roles in tree mortality in this subtropical forest.

Analyzing the Effect of Mandatory Water Restrictions on Water Usage

2020 ◽  
Vol 20 (2) ◽  
Author(s):  
Trey Dronyk-Trosper ◽  
Brandli Stitzel
Keyword(s):  
Water Use ◽  
Water Consumption ◽  
Water Rights ◽  
Water Usage ◽  
Total Water ◽  
Water Restriction ◽  
Way Of Life ◽  
Total Water Consumption ◽  
Water Restrictions

AbstractAs water rights and water usage become an ever more important part of municipalities’ and states’ way of life, it becomes important to understand what policies can be effective for encouraging conservation of water. One method that has been employed at various times and throughout numerous communities is to limit outdoor watering days. We use a dataset with over 3 million property-month observations during the 2007–2015 period in Norman, Oklahoma, to identify whether the periodic implementation of mandatory water restrictions reduces water usage. Our data allow us to exploit variance in the timing of these water restriction programs. Our findings indicate that this policy reduces water consumption by 0.7 % of total water consumption. Additionally, we use home assessment prices to identify heterogeneity in this response, finding that high priced homes are more responsive to water use restrictions.

scholarly journals Mango Leaf Monitoring with Inductive and Capacitive Sensors and Its Comparison with Trunk Dendrometer Measurements

2021 ◽  
Vol 9 (1) ◽  
pp. 28
Author(s):  
Federico Hahn ◽  
Juan Espinoza ◽  
Ulises Zacarías
Keyword(s):  
Magnetic Field ◽  
Hall Effect ◽  
Water Content ◽  
Water Use ◽  
Fruit Trees ◽  
Irrigation Scheduling ◽  
Leaf Water Content ◽  
Water Usage ◽  
Warm Weather ◽  
Hall Sensors

Mango is one of the main fruits grown in Mexico that are exported worldwide, but the trees consume a lot of water, and irrigation scheduling should be implemented to optimize water use. Dendrometers were installed in fruit trees to optimize water usage during 2019 and 2020. A capacitor with Teflon clamps pressurized the leaf, and its dielectric changed with leaf water content. Additionally, Hall sensors were installed in leaves to study the effect of water during mango production. It was found that capacitance tend to be more sensitive than magnetic field monitoring. Higher changes were noted during midday with warm weather. Thresholds from the capacitance and Hall effect sensors can provide signals for irrigation scheduling.

How would irrigation enhance the global BECCS potential in view of sustainable water use?

2021 ◽  
Author(s):  
Zhipin Ai ◽  
Naota Hanasaki
Keyword(s):  
Water Use ◽  
Carbon Capture ◽  
Critical Role ◽  
Carbon Capture And Storage ◽  
Water Withdrawal ◽  
Water Usage ◽  
Sustainable Water Use ◽  
Additional Water ◽  
Sustainable Irrigation ◽  
And Storage

<p>Bioenergy with carbon capture and storage (BECCS) plays a critical role in many stringent scenarios targeting the 2°C goal. Although irrigation is considered a promising way to enhance BECCS potential while reducing the land requirement, it is still unknown where and to what extent it can enhance the global BECCS potential in view of sustainable water use. Based on integrated hydrological simulations, we found that sustainable irrigation without intervention in water usage for other sectors and refrain from exploiting nonrenewable water sources enhanced BECCS potential by only 5–6% (much smaller than 60–71% for unlimited irrigation) above the rainfed potential by the end of this century. Nonetheless, it adds limited additional water withdrawal (166–298 km<sup>3</sup> yr<sup>-1</sup>, corresponding to only 4–7% of the current total withdrawal) compared to that with unlimited irrigation (1392–3929 km<sup>3</sup> yr<sup>-1</sup>, corresponding to 35–98% of the current total withdrawal).</p>

scholarly journals Potential and Actual Water Savings through Improved Irrigation Scheduling in Small-Scale Vegetable Production

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 888 ◽  
Author(s):  
Christoph Studer ◽  
Simon Spoehel
Keyword(s):  
Water Use ◽  
Irrigation Water ◽  
Drip Irrigation ◽  
Water Productivity ◽  
Irrigation Scheduling ◽  
Small Scale ◽  
Vegetable Production ◽  
Usual Practice ◽  
Irrigation Water Use ◽  
Small Scale Farmers

Appropriate irrigation scheduling for efficient water use is often a challenge for small-scale farmers using drip irrigation. In a trial with 12 farmers in Sébaco, Nicaragua, two tools to facilitate irrigation scheduling were tested: the Water Chart (a table indicating required irrigation doses) and tensiometers. The study aimed at evaluating if and to what extent simple tools can reduce irrigation water use and improve water productivity in drip-irrigated vegetable (beetroot; Beta vulgaris L.) production compared with the farmers’ usual practice. Irrigation water use was substantially reduced (around 20%) when farmers irrigated according to the tools. However, farmers did not fully adhere to the tool guidance, probably because they feared that their crop would not get sufficient water. Thus they still over-irrigated their crop: between 38% and 88% more water than recommended was used during the treatment period, resulting in 91% to 139% higher water use than required over the entire growing cycle. Water productivity of beetroot production was, therefore, much lower (around 3 kg/m3) than what can be achieved under comparable conditions, although yields were decent. Differences in crop yield and water productivity among treatments were not significant. The simplified Water Chart was not sufficiently understandable to farmers (and technicians), whereas tensiometers were better perceived, although they do not provide any indication on how much water to apply. We conclude that innovations such as drip irrigation or improved irrigation scheduling have to be appropriately introduced, e.g., by taking sufficient time to co-produce a common understanding about the technologies and their possible usefulness, and by ensuring adequate follow-up support.

scholarly journals Decoupling Urban Water Use and Growth in Response to Water Scarcity

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2868
Author(s):  
Brian D. Richter ◽  
Kendall Benoit ◽  
Jesse Dugan ◽  
Gabriella Getacho ◽  
Natalie LaRoe ◽  
...  
Keyword(s):  
Water Use ◽  
Water Scarcity ◽  
Annual Data ◽  
Urban Water ◽  
Water Usage ◽  
Western Us ◽  
Urban Water Use ◽  
Per Capita ◽  
Residential Use ◽  
Response To Water

Many cities in the western US face difficult challenges in trying to secure water supplies for rapidly growing urban populations in the context of intensifying water scarcity. We obtained annual data from urban water utilities across the western US to document trends in their water usage and service populations. We found that many cities have been able to accommodate population increases while simultaneously reducing their volume of water use, thereby decoupling growth from water use. This outcome is largely attributable to reductions in per-capita residential use. We identify additional untapped potential that can sustain and widen this decoupling for many cities.

Century‐long apparent decrease in intrinsic water‐use efficiency with no evidence of progressive nutrient limitation in African tropical forests

2020 ◽  
Vol 26 (8) ◽  
pp. 4449-4461 ◽  
Author(s):  
Marijn Bauters ◽  
Sofie Meeus ◽  
Matti Barthel ◽  
Piet Stoffelen ◽  
Hannes P. T. De Deurwaerder ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Nutrient Limitation ◽  
Tropical Forests ◽  
Water Use ◽  
Intrinsic Water Use Efficiency ◽  
Apparent Decrease ◽  
Use Efficiency

scholarly journals Land and Water Usage in Beef Production Systems

Animals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 286 ◽  
Author(s):  
Donald M. Broom
Keyword(s):  
Water Use ◽  
Production Systems ◽  
Published Data ◽  
Silvopastoral Systems ◽  
Water Usage ◽  
Beef Production ◽  
Cattle Feed ◽  
Sustainable Systems ◽  
Intensive Rearing ◽  
The Impact

This analysis, using published data, compared all land and conserved water use in four beef production systems. A widespread feedlot system and fertilised irrigated pasture systems used similar amounts of land. However, extensive unmodified pasture systems used three times more land, and semi-intensive silvopastoral systems used four times less land, so the highest use was 13 times the lowest. The amount of conserved water used was 64% higher in feedlots with relatively intensive rearing systems than in fertilised irrigated pasture; in extensive unmodified pasture systems, it was 38% and in semi-intensive silvopastoral systems, it was 21% of the fertilised irrigated pasture value, so the highest use was eight times the lowest. If there was no irrigation of pasture or of plants used for cattle feed, the feedlot water use was 12% higher than the fertilised pasture use and 57% higher than that in semi-intensive silvopastoral systems. These large effects of systems on resource use indicate the need to consider all systems when referring to the impact of beef or other products on the global environment. Whilst the use of animals as human food should be reduced, herbivorous animals that consume food that humans cannot eat and are kept using sustainable systems are important for the future use of world resources.

scholarly journals Agricultural groundwater management in the Upper Bhima Basin, India: current status and future scenarios

2013 ◽  
Vol 17 (2) ◽  
pp. 507-517 ◽  
Author(s):  
L. Surinaidu ◽  
C. G. D. Bacon ◽  
P. Pavelic
Keyword(s):  
Climate Change ◽  
Water Use ◽  
Water Discharge ◽  
Climate Change Impacts ◽  
Current Status ◽  
Small Scale ◽  
Groundwater Levels ◽  
Groundwater Overdraft ◽  
Use Efficiency ◽  
Increasing Demand

Abstract. The basaltic aquifers of the Upper Bhima River basin in southern India are heavily utilized for small-scale agriculture but face increasing demand-related pressures along with uncertainty associated with climate change impacts. To evaluate likely groundwater resource impacts over the coming decades, a regional groundwater flow model for the basin was developed. Model predictions associated with different climate change and abstraction scenarios indicate that the continuation of current rates of abstraction would lead to significant groundwater overdraft, with groundwater elevations predicted to fall by −6 m over the next three decades. Groundwater elevations can however be stabilized, but would require 20–30% of the mean surface water discharge from the basin to be recharged to groundwater, along with reductions in pumping (5–10%) brought about by improved water efficiency practices and/or shifts towards lower-water use crops. Modest reductions in pumping alone cannot stabilize groundwater levels; targeted conjunctive use and improved water use efficiency are also needed.

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