Biomass loss and change in species dominance shift stream community excretion stoichiometry during severe drought

The last decade has brought many changes to Colorado's water supply outlook. Despite the recent economic recession, the state has experienced significant population growth, and Colorado's population is expected to nearly double within the next 40 years. Other pressures on Colorado's water supply include severe drought, a desire to meet multiple needs (i.e., municipal, environmental, recreational) with existing resources, and impacts to agriculture due to water shortages, urbanization, and transfers to new users. To address these challenges, the Colorado Water Conservation Board (CWCB) has undertaken a visioning process to explore solutions to these future water supply challenges. As part of this process, CWCB has led the state in identifying demand and supply strategies to meet the state's future water needs while considering agriculture and the environment. These strategies have been combined into varying portfolios that include methods such as conservation, local water projects, new Colorado River development, and agricultural transfers. This paper details the development and evaluation of these portfolios and describes stakeholder's efforts to balance meeting Colorado's water needs in the future.

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Influence of Discharges from Storage Reservoirs on the Tastes and Odours Appearing in the Seine and Marne Rivers

Water Science & Technology ◽

10.2166/wst.1982.0086 ◽

1982 ◽

Vol 14 (4-5) ◽

pp. 43-58 ◽

Cited By ~ 1

Author(s):

M Rizet ◽

J Mouchet

Keyword(s):

Water Quality ◽

Quality Parameters ◽

Water Quality Parameters ◽

Severe Drought ◽

Storage Reservoirs ◽

Metabolite Concentrations

This study was conducted in order to understand the taste and odour problems that occurred in the Seine and the Marne rivers during the severe drought of 1976. Samples were taken every 15 days from several locations in the rivers themselves and from storage reservoirs upstream from Paris. Algae and actinomycetes were identified and counted. Metabolite concentrations were measured. These data were correlated with threshold odor numbers and bacteriological water quality parameters.

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An Experimental Analysis of Biological Factors Contributing to Stream Community Structure

Ecology ◽

10.2307/1939035 ◽

1980 ◽

Vol 61 (6) ◽

pp. 1283-1290 ◽

Cited By ~ 43

Author(s):

Barbara L. Peckarsky ◽

Stanley I. Dodson

Keyword(s):

Community Structure ◽

Experimental Analysis ◽

Biological Factors ◽

Stream Community

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Exploring the past of Mavrovouni forest in the Pindus Mountain range (Greece) using tree rings of Bosnian pines

Trees ◽

10.1007/s00468-021-02189-6 ◽

2021 ◽

Author(s):

Anastasia Christopoulou ◽

Nikolaos M. Fyllas ◽

Barbara Gmińska-Nowak ◽

Yasemin Özarslan ◽

Margarita Arianoutsou ◽

...

Keyword(s):

Fire History ◽

Ring Width ◽

Severe Drought ◽

Mountain Range ◽

Degree Days ◽

Mature Trees ◽

The Past ◽

Natural Agent ◽

Fire Ignition ◽

Animal Grazing

Abstract Key message Long Bosnian pine chronologies from different mountains are shaped by different climatic parameters and can help identify past drought events and reconstruct landscape histories. Abstract We developed a 735-year-long Pinus heldreichii chronology from the southern distribution limit of the species, expanding the available database of long Bosnian pine chronologies. Tree-ring growth was mainly positively correlated with growing degree days (GDD: r1950–2018 = 0.476) while higher temperatures during both winter and growing season also enhanced growth (TWT: r1950–2018 = 0.361 and TGS: 0.289, respectively). Annual precipitation, during both calendar and water years, had a negative but weaker impact on annual tree growth. The newly developed chronology correlates well with chronologies developed from the neighboring mountains. The years with ring width index (RWI) lower than the average were found to correspond to cool years with dry summers. Still, the newly developed chronology was able to capture severe drought events, such as those in 1660, 1687, and 1725. Several old living trees had internal scars presumably caused by fires. Therefore, old mature trees could be used for fire history reconstruction in addition to climate reconstruction. Although the presence of lightning scars indicates an important natural agent of fire ignition, human activities associated with animal grazing could also be an underlying reason for fires in the region.

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Monoculture-based consumer-resource models predict species dominance in mixed batch cultures of dinoflagellates

Harmful Algae ◽

10.1016/j.hal.2020.101921 ◽

2020 ◽

Vol 99 ◽

pp. 101921

Author(s):

M. De Rijcke ◽

J.M. Baert ◽

N. Brion ◽

M.B. Vandegehuchte ◽

F. De Laender ◽

...

Keyword(s):

Batch Cultures ◽

Species Dominance ◽

Consumer Resource ◽

Mixed Batch

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Role of Suillus placidus in Improving the Drought Tolerance of Masson Pine (Pinus massoniana Lamb.) Seedlings

Forests ◽

10.3390/f12030332 ◽

2021 ◽

Vol 12 (3) ◽

pp. 332

Author(s):

Min Li ◽

Haoyun Wang ◽

Xizhou Zhao ◽

Zhongke Lu ◽

Xueguang Sun ◽

...

Keyword(s):

Drought Stress ◽

Defense Mechanism ◽

Southern China ◽

Dry Weight ◽

Pinus Massoniana ◽

Photosynthetic Performance ◽

Ectomycorrhizal Fungus ◽

Severe Drought ◽

Masson Pine ◽

Pine Seedlings

Masson pine is an important afforestation species in southern China, where seasonal drought is common. The present study focused on the effects of Suillus placidus, an ectomycorrhizal fungus, inoculation on the growth and physiological and biochemical performance of masson pine seedlings under four different watering treatments (well-watered, mild drought, moderate drought, and severe drought) to evaluate the symbiotic relationship between S. placidus and masson pine seedlings. Ectomycorrhizal-inoculated (ECM) and non-inoculated (NM) seedlings were grown in pots and maintained for 60 days using the weighing method. Results showed that seedlings’ growth, dry weight, RWC, chlorophyll content, PSII efficiency, and photosynthesis decreased as drought stress intensified in both ECM and NM plants. This suggests that drought stress significantly limits the growth and photosynthetic performance of masson pine seedlings. Nevertheless, increased An/gs and proline contents in both NM and ECM prevented oxidative damage caused by drought stress. In addition, increased peroxidase (POD) activity is an essential defense mechanism of ECM seedling under drought stress. Compared with NM, ECM seedlings showed faster growth, higher RWC, and photosynthetic performance, and lower lipid peroxidation in cell membranes under drought stress, as indicated by higher POD activity and lower proline and malondialdehyde (MDA). Our experiment found that S. placidus inoculation can enhance the drought resistance of masson pine seedlings by increasing antioxidant enzyme activity, water use efficiency, and proline content, thereby enhancing growth under water-deficiency conditions. S. placidus can be used to cultivate high-quality seedlings and improve their survival in regions that experience seasonal droughts.

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Exogenously Used 24-Epibrassinolide Promotes Drought Tolerance in Maize Hybrids by Improving Plant and Water Productivity in an Arid Environment

Plants ◽

10.3390/plants10020354 ◽

2021 ◽

Vol 10 (2) ◽

pp. 354

Author(s):

El-Sayed M. Desoky ◽

Elsayed Mansour ◽

Mohamed M. A. Ali ◽

Mohamed A. T. Yasin ◽

Mohamed I. E. Abdul-Hamid ◽

...

Keyword(s):

Drought Tolerance ◽

Agronomic Traits ◽

Water Productivity ◽

Positive Association ◽

Net Photosynthesis ◽

Antioxidant Enzyme Activities ◽

Severe Drought ◽

Arid Environments ◽

Maize Hybrids ◽

Semi Arid

The influence of 24-epibrassinolide (EBR24), applied to leaves at a concentration of 5 μM, on plant physio-biochemistry and its reflection on crop water productivity (CWP) and other agronomic traits of six maize hybrids was field-evaluated under semi-arid conditions. Two levels of irrigation water deficiency (IWD) (moderate and severe droughts; 6000 and 3000 m3 water ha−1, respectively) were applied versus a control (well-watering; 9000 m3 water ha−1). IWD reduced the relative water content, membrane stability index, photosynthetic efficiency, stomatal conductance, and rates of transpiration and net photosynthesis. Conversely, antioxidant enzyme activities and osmolyte contents were significantly increased as a result of the increased malondialdehyde content and electrolyte leakage compared to the control. These negative influences of IWD led to a reduction in CWP and grain yield-related traits. However, EBR24 detoxified the IWD stress effects and enhanced all the above-mentioned parameters. The evaluated hybrids varied in drought tolerance; Giza-168 was the best under moderate drought, while Fine-276 was the best under severe drought. Under IWD, certain physiological traits exhibited a highly positive association with yield and yield-contributing traits or CWP. Thus, exogenously using EBR24 for these hybrids could be an effective approach to improve plant and water productivity under reduced available water in semi-arid environments.

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