Does successive exposure of conifer seedlings to drought prepare them for subsequent extreme drought?

2021 ◽  
Author(s):  
Ehren Moler Ehren Moler
Keyword(s):  
Extreme Drought ◽  
Conifer Seedlings

4Flowering Responses of Alpine Meadow Plant in the Qinghai-Tibetan Plateau to Extreme Drought Imposed in Different Periods

2013 ◽  
Vol 19 (2) ◽  
pp. 272-279 ◽  
Author(s):  
Chengxiang MOU ◽  
Geng SUN ◽  
Peng LUO ◽  
Zhiyuan WANG ◽  
Guangrong LUO
Keyword(s):  
Tibetan Plateau ◽  
Alpine Meadow ◽  
Extreme Drought

scholarly journals Root carbon and nutrient homeostasis determines downy oak sapling survival and recovery from drought

2021 ◽  
Author(s):  
Sheng-Nan Ouyang ◽  
Arthur Gessler ◽  
Matthias Saurer ◽  
Frank Hagedorn ◽  
De-Cai Gao ◽  
...  
Keyword(s):  
Soluble Sugar ◽  
Recovery Process ◽  
Extreme Drought ◽  
Tree Level ◽  
Starch Degradation ◽  
Minor Role ◽  
Climate Conditions ◽  
Physiological Processes ◽  
Drought Relief ◽  
A Minor

Abstract The role of carbon (C) and nutrient uptake, allocation, storage and especially their interactions in survival and recovery of trees under increased frequencies and intensities of drought events is not well understood. A full factorial experiment with four soil water content regimes ranging from extreme drought to well-watered conditions and two fertilization levels was carried out. We aimed to investigate whether nutrient addition mitigates drought effects on downy oak (Quercus pubescens Willd.) and whether storage pools of non-structural carbohydrates (NSC) are modified to enhance survival after 2.5 years of drought and recovery after drought relief. Physiological traits, such as photosynthesis, predawn leaf water potential as well as tissue biomass together with pools and dynamics of NSC and nutrients at the whole-tree level were investigated. Our results showed that fertilization played a minor role in saplings’ physiological processes to cope with drought and drought relief, but reduced sapling mortality during extreme drought. Irrespective of nutrient supply, Q. pubescens showed increased soluble sugar concentration in all tissues with increasing drought intensity, mostly because of starch degradation. After 28 days of drought relief, tissue sugar concentrations decreased, reaching comparable values to those of well-watered plants. Only during the recovery process from extreme drought, root NSC concentration strongly declined, leading to an almost complete NSC depletion after 28 days of rewetting, simultaneously with new leaves flushing. These findings suggest that extreme drought can lead to root C exhaustion. After drought relief, the repair and regrowth of organs can even exacerbate the root C depletion. We concluded that under future climate conditions with repeated drought events, the insufficient and lagged C replenishment in roots might eventually lead to C starvation and further mortality.

scholarly journals Impact of Extreme Drought Climate on Water Security in North Borneo: Case Study of Sabah

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1135
Author(s):  
Carolyn Payus ◽  
Lim Ann Huey ◽  
Farrah Adnan ◽  
Andi Besse Rimba ◽  
Geetha Mohan ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resource ◽  
Supply And Demand ◽  
Water Security ◽  
Water Levels ◽  
Extreme Drought ◽  
Northeast Monsoon ◽  
Water Insecurity ◽  
The North ◽  
North Borneo

For countries in Southeast Asia that mainly rely on surface water as their water resource, changes in weather patterns and hydrological systems due to climate change will cause severely decreased water resource availability. Warm weather triggers more water use and exacerbates the extraction of water resources, which will change the operation patterns of water usage and increase demand, resulting in water scarcity. The occurrence of prolonged drought upsets the balance between water supply and demand, significantly increasing the vulnerability of regions to damaging impacts. The objectives of this study are to identify trends and determine the impacts of extreme drought events on water levels for the major important water dams in the northern part of Borneo, and to assess the risk of water insecurity for the dams. In this context, remote sensing images are used to determine the degree of risk of water insecurity in the regions. Statistical methods are used in the analysis of daily water levels and rainfall data. The findings show that water levels in dams on the North and Northeast Coasts of Borneo are greatly affected by the extreme drought climate caused by the Northeast Monsoon, with mild to the high risk recorded in terms of water insecurity, with only two of the water dams being water-secure. This study shows how climate change has affected water availability throughout the regions.

Cylindrocarpon and Fusarium root colonization of Douglas-fir seedlings from British Columbia reforestation sites

1998 ◽  
Vol 28 (8) ◽  
pp. 1198-1206 ◽  
Author(s):  
Paige E Axelrood ◽  
William K Chapman ◽  
Keith A Seifert ◽  
David B Trotter ◽  
Gwen Shrimpton
Keyword(s):  
British Columbia ◽  
Pseudotsuga Menziesii ◽  
Root Colonization ◽  
Linear Trend ◽  
Poor Performance ◽  
Douglas Fir ◽  
Root Infection ◽  
Significant Linear Trend ◽  
Conifer Seedlings ◽  
Cylindrocarpon Destructans

Poor performance of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations established in 1987 has occurred in southwestern British Columbia. Affected sites were planted with 1-year-old container stock that exhibited some root dieback in the nursery. A study was initiated in 1991 to assess Cylindrocarpon and Fusarium root infection in planted and naturally regenerating (natural) Douglas-fir seedlings from seven affected plantations. Percentages of seedlings harboring Cylindrocarpon spp.and percent root colonization were significantly greater for planted seedlings compared with natural seedlings. A significant linear trend in Cylindrocarpon root colonization was observed for planted seedlings with colonization levels being highest for roots closest to the remnants of the root plug and decreasing at distances greater than 10cm from that region. This trend in Cylindrocarpon colonization was not observed for natural seedlings. Cylindrocarpon destructans (Zins.) Scholten var. destructans and C.cylindroides Wollenw. var. cylindroides were the only species isolated from planted and natural conifer seedlings. For most sites, percentage of seedlings harboring Fusarium spp.and percent Fusarium root colonization were less than for Cylindrocarpon. Recovery of Fusarium spp.from seedlings and root colonization levels were not significantly different for planted and natural seedlings from all sites.

Integrated vegetation management in California – advances and future

1991 ◽  
Vol 67 (5) ◽  
pp. 528-531 ◽  
Author(s):  
Gary O. Fiddler ◽  
Philip M. McDonald
Keyword(s):  
Good Control ◽  
Vegetation Management ◽  
Bureau Of Land Management ◽  
Private Industry ◽  
Conifer Seedlings ◽  
Central California ◽  
Competing Vegetation ◽  
Growing Seasons ◽  
Survival And Growth ◽  
Mechanical Release

A study on alternatives for releasing young conifer plantations on National Forests in northern and central California was started in 1980, and enlarged to include State of California, Bureau of Land Management, and private industry lands. Forty studies involving chemical, manual, mechanical, mulch, and animal treatments have been established and their effect on the survival and growth of conifer seedlings is being quantified. Plant diversity and succession on both treated and untreated sites are being recorded. The oldest study has had 10 growing seasons since the first treatments were applied. To release conifer seedlings, a treatment radius of at least 1.5 meters is required; smaller radii do not provide enough site resources for acceptable growth. Diameter, rather than height, is the best indicator of release. Some non-phenoxy chemicals show promise for good control of competing vegetation. Mechanical release requires additional treatments to effectively control shrubs. Mulching has given limited results to date. Manual treatments, if applied to non-sprouting and nonrhizomatous plants soon after planting, and usually more than once, provide adequate control of competing vegetation, but are costly.

Warming increased bark beetle‐induced tree mortality by 30% during an extreme drought in California

2021 ◽  
Author(s):  
Zachary J. Robbins ◽  
Chonggang Xu ◽  
Brian H. Aukema ◽  
Polly C. Buotte ◽  
Rutuja Chitra‐Tarak ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Tree Mortality ◽  
Extreme Drought

Extreme drought effects and recovery patterns in the benthic communities of temperate streams

Limnetica ◽  
2014 ◽  
pp. 281-296
Author(s):  
Calapez, Ana Raquel ◽  
Elias, Carmen L. ◽  
Almeida, Salomé F. P. ◽  
Feio, Maria João
Keyword(s):  
Benthic Communities ◽  
Extreme Drought ◽  
Temperate Streams ◽  
Drought Effects
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