scholarly journals Interactions of nutrient and water availability control growth and diversity effects in a Salix two‐species mixture

Ecohydrology ◽  
2021 ◽  
Author(s):  
Magnus Lindh ◽  
Stefanie Hoeber ◽  
Martin Weih ◽  
Stefano Manzoni
Keyword(s):  
Water Availability ◽  
Control Growth ◽  
Species Mixture ◽  
Diversity Effects

scholarly journals Dry matter yield of dryland and irrigated mixtures of Caucasian clover, white clover and perennial ryegrass over 5 years at Lincoln University

2018 ◽  
pp. 73-80
Author(s):  
Alistair D Black ◽  
Richard J Lucas
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
Interspecific Interactions ◽  
Synergistic Interactions ◽  
Diversity Effect ◽  
Species Mixture ◽  
Irrigation Levels ◽  
Lincoln University ◽  
Diversity Effects

This experiment investigated the effects of Caucasian clover (CC), white clover (WC), perennial ryegrass (RG) and their mixtures on dry matter (DM) yield under dryland and irrigated conditions over 5 years (1st July-30th June) at Lincoln University. Seven mixtures of the three species (three pure, three binary and one ternary) were sown in November 1999, grown with and without irrigation, and grazed by sheep. Total annual DM yield in Years 2-6 (2000/2001-2004/2005) was analysed. Clover-RG mixtures yielded more than the average monoculture yields of their constituent species (over-yielding). This diversity effect was 1.8-7.0 t DM/ha for WC-RG over all 5 years and 2.7-4.6 t DM/ ha for CC-RG in Years 3-6. There was no additional yield benefit from the three-species mixture. Diversity effects were due to synergistic interactions between the clovers and RG, which were similar for CC and WC once established. The interspecific interactions persisted despite changes in botanical composition across irrigation levels and years.

Are water and nutrient limitations promoting complementarity in minimal plant communities?

2021 ◽  
Author(s):  
Stefano Manzoni ◽  
Magnus Lindh ◽  
Stefanie Hoeber ◽  
Martin Weih
Keyword(s):  
Nutrient Limitation ◽  
Resource Use ◽  
Water Availability ◽  
Resource Competition ◽  
Irrigation Treatment ◽  
Resource Limitation ◽  
Niche Separation ◽  
Diverse Communities ◽  
Set Up ◽  
Diversity Effects

<p>It has been hypothesized that resource limitation promotes complementary resource use by different species in a plant community. According to this hypothesis, more diverse communities would use available resources more efficiently by exploiting contrasting niches. As a result, diverse communities would have higher overall productivity than monospecific stands in resource-limited systems. While this hypothesis has been tested in various experiments, less attention has been devoted to combined water and nutrient limitation, and variations in complementarity vs. selection effects through time. Understanding these dynamics is particularly important in the context of climatic changes that might alter resource availability—specifically the timing and amount of rainfall. To assess how combined resource limitation alters allocation and productivity in monocultures vs. species mixtures, we set up a pot experiment with full factorial manipulation of both water and nutrient availability, for monocultures and mixtures of two Salix species. To capture expected increases in rainfall intermittency, water availability was manipulated by changing the timing of the water additions—not the total amount provided. Thus, in the infrequent irrigation treatment, longer dry periods occurred between larger water additions, leading to lower water availability at the end of each dry period, compared to the frequent irrigation treatment. The selected species differ in functional traits such as specific leaf area and stem diameter to height ratio, suggesting that they might fill different niches thereby allowing us to test the complementarity hypothesis despite them being closely related. With this experimental set up, we found that the Salix species with higher growth rate suffered the most water stress and that nutrient limitation caused higher root-to-shoot biomass ratio in both species. Both effects were expected, as larger plants growing in nutrient-rich conditions deplete water resources faster, and it is well known that nutrient shortage promotes allocation belowground. Regarding diversity effects, we found that both complementarity and net diversity effects increased through time as resource competition increased, and contrary to expectations were overall higher in the high nutrient supply and frequent watering treatments. These results suggest stronger interactions among the relatively larger plants growing under resource-rich conditions, compared to weak interactions among small plants. In turn, these stronger interactions among large plants might lead to more marked niche separation allowing for resource use complementarity.</p>

Examining workgroup diversity effects: Do group-retention rules help or hinder?

2009 ◽  
Author(s):  
David J. Stanley ◽  
Natalie J. Allen ◽  
Helen M. Williams ◽  
Sarah J. Ross
Keyword(s):  
Workgroup Diversity ◽  
Diversity Effects

Impact of water availability on winter wheat ( Triticum aestivum L.) yield characteristics

2010 ◽  
Vol 59 (1) ◽  
pp. 151-156 ◽  
Author(s):  
H. Klupács ◽  
Á. Tarnawa ◽  
I. Balla ◽  
M. Jolánkai
Keyword(s):  
Winter Wheat ◽  
Water Supply ◽  
Water Availability ◽  
Grain Quality ◽  
Physiological Condition ◽  
Triticum Aestivum L ◽  
Annual Precipitation ◽  
Average Depth ◽  
Experimental Site ◽  
Yield Quality

Water supply of crop plants is the most essential physiological condition influencing quality and quantity performance of grain yield. In a 12-year experimental series of winter wheat agronomic trials run at the Nagygombos experimental site (Hungary) the effect of water availability has been studied. The location represents the typical average lowland conditions of the country, the annual precipitation of the experimental site belonging to the 550–600 mm belt of the Northern edges of the Great Hungarian Plain, while the average depth of groundwater varies between 2 to 3 metres. Crop years with various precipitation patterns have had different impacts on crop yield quality and quantity. Yield figures were in positive correlation with annual precipitation in general. Water availability had diverse influence on quality manifestation. Good water supply has often resulted in poorer grain quality, especially wet gluten and Hagberg values have been affected by that. Drought reduced the amount of yield in general, but contributed to a better quality manifestation in some of the crop years.

CRITICAL FACTORS OF WATER CONTENT FOR FISH STOCKS IN THE WATER RESERVOIRS OF KAZAKHSTAN

2017 ◽  
pp. 9-18
Author(s):  
Saule Zhangirovna Asylbekova ◽  
Kuanysh Baibulatovich Isbekov ◽  
Evgeniy Vyacheslavovich Kulikov
Keyword(s):  
Water Content ◽  
Water Level ◽  
Water Availability ◽  
Hydrological Regime ◽  
Fishing Effort ◽  
Water Reservoirs ◽  
The Caspian Sea ◽  
Annual Fish ◽  
Commercial Fish ◽  
Fish Stocks

The hydrological regime of water reservoirs in different years has a decisive impact on the abundance of commercial fish stocks and the quality of ichthyocenoses. In this connection in 2015-2016 there was conducted a retrospective analysis and ranking of hydrological regime impact on these factors. The paper gives evaluation of catches and fish stocks under different scenarios of water availability in the main fishing ponds of the Republic of Kazakhstan that give about 80% of the annual fish catch of the country (except the Caspian Sea). There were analyzed 2000 factors of hydrological regime (water level, annual discharge) and 1845 factors of fishing stocks (catches, abundance, fish biomass). The paper determines the critical characteristics of water availability for fish stocks. There have been proposed a number of administrative decisions and actions in case if water content would approach to the critical level. Among them: limitation of fish catches in the following year; widening zones restricted for fishing; intensification of safety measures of the fish young in residual ponds during arid periods; introduction of catch standards for a unit of fishing effort in low-water years, high-water years and years with normal water level in rivers.

Use of Natural Ingredients to Control Growth of Clostridium perfringens on Frankfurters and Ham

2010 ◽  
Author(s):  
Armitra Jackson ◽  
Gary Sullivan ◽  
Joseph G. Sebranek ◽  
James S. Dickson
Keyword(s):  
Clostridium Perfringens ◽  
Control Growth
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