Plant Biology Commons^™

Species Richness Increased Yield Stability In Intensively Managed Grasslands Subjected To Experimental Drought, J. A. Finn, M. Suter, E. Haughey, D. Hofer, A. Lüscher

IGC Proceedings (1977-2023)

Climate change is expected to cause an increase in the frequency and intensity of drought events. Over two years we investigated the effects of experimentally imposed drought on intensively managed grassland communities (5 m x 6 m plots) of varying richness (1, 2 and 4 species), and comprising four species (Lolium perenne L., Cichorium intybus L., Trifolium repens L., Trifolium pratense L.). In each year a summer drought period of nine weeks with complete exclusion of precipitation was simulated, inducing severe drought stress at Reckenholz (Zürich, Switzerland), and extreme drought stress at Wexford (Ireland). Mean yield and plot-to-plot variance …

Elevated Co2 And Extreme Climatic Events Modify Nitrogen Content And Ruminal Protein Digestion Of Temperate Grassland, V. Niderkorn, C. Picon-Cochard

IGC Proceedings (1977-2023)

This study was aimed at analyzing changes in nitrogen (N) content and in vitro protein rumen digestion of an upland grassland exposed to climate changes in controlled conditions. Monoliths of grassland were inserted in 12 macrocosms in which climatic conditions for the 2050s were simulated (i.e., +2.3°C and 33 mm less precipitation compared to the current climatic conditions). Six of them were subjected to ambient CO₂ (390 ppm) while the other six were subjected to elevated CO₂ (520 ppm). After four months, an extreme climatic event (ECE) consisting of four weeks of reducted precipitation (-50%) followed by two …

Climate Change Threats To Semi-Arid Transhumance Grazing Systems: Proposals For Adaptation In Cabo Verde, J. F. Castro, S. Tavares, M. Castro

IGC Proceedings (1977-2023)

Global warming has changed the rainfall regime in the Sahelian region, endangering and widespread poverty and chronic famines in Cape Verde, where rural communities' well-being and food security depend on rainy agriculture. Local responses to rainfall new patterns and scarcity have been livestock reduction with significant revenue losses. Together with dry mist occurrences, these environmental constraints demand to define priority actions to adapt and mitigate climate change's direct impacts. According to fifty household inquiries, this work explains the transhumant grazing practices on a semi-arid plateau in Tarrafal (Santiago, Cabo Verde), prospecting adaptation alternatives for sustainability. We related grazing patterns and …

Interactive Effects Of Drought And Fire On Co-Existing Woody And Herbaceous Communities In A Temperate Mesic Grassland, R. Keen, J. Nippert, E. Tooley, K. O’Keefe, S. Bachle, M. Sandwick

IGC Proceedings (1977-2023)

Increased drought and woody encroachment are likely to have substantial and interactive effects on grassland carbon and water cycling in the future. However, we currently lack necessary information to accurately predict grassland responses to drought-by-fire interactions in areas experiencing woody encroachment. A more thorough understanding of these interactive effects on grass-shrub physiology would improve the effectiveness of demographic vegetation models and refine predictions of future changes in grassland ecosystem function. To this end, we constructed passive rainout shelters over mature Cornus drummondii shrubs and co-existing grasses in two fire treatments (1-year and 4-year burn frequency) at the Konza Prairie Biological …

Characterization Of Salt And Drought Tolerance In Sunflower (Helianthus Annuus L.), Sevgi Saylak

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Consequent to the increasing world population, food sources are needed to be increased to meet the nutritional needs. However, due to natural processes and agricultural activities, the most destructive environmental factors that limit crop production, soil salinity, and drought-exposed areas are growing. As one of the major oilseed crops, sunflower (Helianthus annuus L.), is considered to be moderately tolerant to salt and drought. Although it can grow in arid to semi-arid regions, increasing salinity and drought might adversely affect sunflower production. This study aimed to investigate several sunflower germplasms' morphological responses to salt and drought stresses. For this purpose, …

Inactivation Of The Entire Arabidopsis Group Ii Gh3s Confers Tolerance To Salinity And Water Deficit, Rubén Casanova-Sáez, Eduardo Mateo-Bonmatí, Jan Šimura, Aleš Pěnčík, Ondřej Novák, Paul Staswick, Karin Ljung

Department of Agronomy and Horticulture: Faculty Publications

Indole-3-acetic acid (IAA) controls a plethora of developmental processes. Thus, regulation of its concentration is of great relevance for plant performance. Cellular IAA concentration depends on its transport, biosynthesis and the various pathways for IAA inactivation, including oxidation and conjugation.

Group II members of the GRETCHEN HAGEN 3 (GH3) gene family code for acyl acid amido synthetases catalysing the conjugation of IAA to amino acids. However, the high degree of functional redundancy among them has hampered thorough analysis of their roles in plant development.

In this work, we generated an Arabidopsis gh3.1,2,3,4,5,6,9,17 (gh3oct) mutant to knock out the group II …

Forage Quality And The Environment, C. E. Lascano, A. Schmidt, R. Barahona

IGC Proceedings (1977-2023)

The influence of environmental factors on forage quality of temperate and tropical grasses has been reviewed by several authors, who summarized how light, temperature, drought and soil nutrients influence chemical composition, and digestibility of forages grown in contrasting areas of the world. The effects of season of the year on forage growth, grazing behavior and animal performance have also been the subject of numerous papers and reviews. However, there are few recent reviews that summarize how changes in climatic and edaphic factors influence forage quality of legumes with variable levels of condensed tannins (CT), which are important secondary compounds in …

The Effect Of Water Deficits During Flowering And Seed Production On Cultivars Of Subterranean Clover And Annual Medic, E. C. Wolfe, W. J. Collins, R. C. Rossiter, W. R. Stern

IGC Proceedings (1977-2023)

In improved pastures in inland southern Australia, the persistence and growth of annual pasture legumes depends in part on their ability to produce and conserve abundant seed for regeneration and production. For near-maximum seed production in spring, adequate soil water is needed for at least 70 days in subterranean clover (Trifolium subterraneum) and medic (Medicago) species. Water deficits during spring are a common occurrence, and they appear to be increasing in frequency. The effect of relatively short periods of water deficit during reproductive development has received some attention but the findings conflict. The present experiment was …

Effect Of Drought Stress On Fibre Digestibility Of Corn For Silage, G. Ferreira, C. L. Teets, A. M. Kingori, J. O. Ondiek

IGC Proceedings (1977-2023)

Limited information exists about the impact of drought stress on corn silage digestibility. The objective of this study was to determine the effect of irrigation on in situ NDF digestibility of corn tissues grown under controlled conditions in a greenhouse. Five commercial corn hybrids were planted in pots and grown in a greenhouse. Pots were subjected to an abundant or restricted irrigation regime. Leaf blades and stem internodes were collected from the upper and bottom portion of each hybrid. Tissue samples were incubated in the rumen of 3 rumen-cannulated cows for 0, 3, 6, 12, 24, 48, 96, and 240 …

Strategies For Assessing Grassland Degradation With Biogeochemical Models, S. Rolinski, S. B. Wirth, C. Müller, B. Tietjen

IGC Proceedings (1977-2023)

Marginal grasslands provide the basis for livestock rearing and rural livelihoods globally, but are subject to permanent degradation from mismanagement and climate change. Global biogeochemical models are so far not able to represent degradation tipping points in marginal grasslands because plant growth is dependent only on bio-climatic conditions and nutrient availability. Due to their central role for sustaining livelihoods, this lack of representation in such models needs to be addressed. We present an idea on processes and interactions to be considered and on the actual implementation of necessary changes. The model for which we exemplarily develop implementation strategies, LPJmL, accounts …

Hydraulic Responses Of Shrubs And Grasses To Fire Frequency And Drought In A Tallgrass Prairie Experiencing Bush Encroachment, K. O’Keefe, R. Keen, E. Tooley, S. Bachle, J. B. Nippert, K. Mcculloh

IGC Proceedings (1977-2023)

The increase in abundance and density of woody plants in herbaceous ecosystems (i.e. bush encroachment) is occurring globally and is driven by reduced fire frequency, climate change, and the utilization of deeper, more reliable soil water by woody plants. Thus, a comprehensive understanding of the physiological processes through which woody and herbaceous plants use water will provide greater insight into the mechanisms of bush encroachment, as well as the trajectory of encroachment in a changing climate. Our objective was to assess how experimental changes in water availability and fire frequency impact belowground water-use traits in Cornus drummondii, the primary …

Climate Variability In The Woodbush Granite Grasslands Of South Africa: Effects On Grassland Diversity, M. Muller, F. Siebert, A. Linstädter, D. I. Thompson, S. J. Siebert

IGC Proceedings (1977-2023)

South African old-growth grasslands are hyper-diverse ecosystems which evolved under naturally occurring rainfall variability. It is predicted that future precipitation patterns will become more variable, which could lead to increased frequencies of extreme and prolonged drought events. This study aimed to investigate the effects of climate variability on plant diversity of the fragmented pristine, mistbelt grasslands of the Woodbush Granite Grasslands (WGG) at Haenertsburg, South Africa. It has been reported that species composition has changed substantially in this area, as disturbance-tolerant species enter these systems or existing competitor species become more dominant. A Temporal Beta-diversity Index (TBI) was used to …

Adaptation Of Forage Species To Drought, D. J. Barker, J. R. Caradus

IGC Proceedings (1977-2023)

Variability in rainfall is the single greatest cause of variation in forage production for a given site. Current climate scenarios predict future annual rainfall to decrease at some geographic regions. The intensity of future rainfall is also predicted to increase at other regions, with the expectation of greater variability in soil moisture. The adaptation of forage species to drought is an issue that is likely to remain with us into the future.

Precise definitions are critical to water relations work, and imprecise use of terms has complicated comparisons of some studies on plant response to drought. Drought is a purely …

Defoliation And Water Deficit: Their Influence On Pasture Growth And Water Use Of White Clover, F. H. Santiñaque

IGC Proceedings (1977-2023)

With the objective of understanding the physiological basis of defoliation and water use relationships of white clover (Trifolium repens L.) pastures during water deficits, an experiment in controlled conditions was carried out. Outdoors nine liters pots were filled with a loam-clay soil with a water content at field capacity (FC), of 35%(w/w), at a bulk density of 1.1 g/cm³. Pre-germinated and inoculated clover seeds were transplanted, and the number of plants was adjusted to permit the development of full plant cover. The level of P in the soil did not limit plant establishment or growth. The …

The Grassbank Concept: Potential Applications In China?, Wenjun Li, Lynn Huntsinger, Sally K. Fairfax

IGC Proceedings (1977-2023)

No abstract provided.

Amino Acid And Protein Incorporation In Water‐Stressed Perennial Ryegrass, W. J. Jung, B. R. Lee, L. S. Li, Y. L. Jin, T. H. Kim

IGC Proceedings (1977-2023)

No abstract provided.

Effect Of Hydrogen Peroxide On Physiological Quality And Germination Of Aged Pumpkin Seeds Under Drought Stress Condition [Research Note], Hossein Reza Rouhi, Mohammad Hasan Vafaei, Maryam Saman, Ali Abbasi Surki

The Philippine Agricultural Scientist

The physiological quality of seeds decreases during their storage under unfavourable conditions. These deteriorated seeds exhibit a poorer performance, especially under stress conditions. A factorial experiment was conducted to investigate the effects of H₂O₂ on the germination of aged pumpkin seeds under drought stress. Hydroprimed seeds and also the seeds pre-treated with 100, 200, and 400 μM H₂O₂ were exposed to drought (0, -0.2, -0.4, and -0.6 MPa applied using PEG). Under drought conditions, seeds primed with H₂O₂ showed improved germination percentages and rates, higher vigour index, greater plumule and radicle …

Identification, Evaluation And Molecular Characterization Of Stylosanthes Seabrana--A Potential And Nutritious Range Legume Having Wider Applicability In India, A. Chandra, R. K. Bhatt, A. B. Majumdar, S. Kumar, D. Nagaich, K. Kumar

IGC Proceedings (1977-2023)

No abstract provided.

Carbon Isotope Discrimination, Selection Response, And Forage Production Of Tall Fescue In Contrasting Environments, R. C. Johnson, Andrew A. Hopkins, M. A. Evans

IGC Proceedings (1977-2023)

No abstract provided.

Metabolic Response Of Lolium Perenne To Drought Stress, Heike Hahn, J. Kopka, Oliver Fiehn, B. Scott

IGC Proceedings (1977-2023)

No abstract provided.

Spatial Patterns Of Range Management And Fodder Resources: How Important Is Local Reserve Biomass?, Anja Linstädter, J. Eisold, Gisela Baumann

IGC Proceedings (1977-2023)

No abstract provided.

Application Of Forage Monitoring Technology To Track Drought Occurrences: Experiences From Eastern Africa, R. Kaitho, J. Ndung'u, G. Kariuki, M. Kingamkono, J. Gutta, E. Kebebe, P. Dyke

IGC Proceedings (1977-2023)

No abstract provided.

Growth And Water Use Of Perennial Ryegrass And Tall Fescue Under Different Irrigation Treatments, R. J. Martin, Trevor L. Knight, R. N. Gillespie, M. U. Riddle, Tom J. Fraser

IGC Proceedings (1977-2023)

No abstract provided.

Gobi Forage: An Early Warning System For Livestock In The Gobi Region Of Mongolia, L. Bolor-Erdene, Jay Peter Angerer, Sean Granville-Ross, M. Urgamal, D. Narangarel, D. Tsogoo, Tim Stewart, Dennis Sheehy

IGC Proceedings (1977-2023)

No abstract provided.

Verification Of A Forage Simulation Model Used For A Livestock Early Warning System In The Gobi Region Of Mongolia, Jay Peter Angerer, L. Bolor‐Erdene, M. Urgamal, D. Tsogoo

IGC Proceedings (1977-2023)

No abstract provided.

Diachronic Analysis Of Vegetation In The Sylvopastoral Zone (Senegal): What Lesson To Learn From?, A. T. Diop, A. Diouf, A. Wane

IGC Proceedings (1977-2023)

No abstract provided.

The Study Of Salinity And Drought Stress Effects On Three Range Species Agropyron Intermedium, Avena Barbata And Panicum Antidotale From Iran, M. M. Sharifi Kashan, Z. Tolui

IGC Proceedings (1977-2023)

No abstract provided.

Leaf Traits And Performance Vary With Plant Age And Water Availability In Artemisia Californica, Jennifer L. Funk, Julie E. Larson, Gregory Vose

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background and aims
Leaf functional traits are strongly tied to growth strategies and ecological processes across species, but few efforts have linked intraspecific trait variation to performance across ontogenetic and environmental gradients. Plants are believed to shift towards more resource-conservative traits in stressful environments and as they age. However, uncertainty in how intraspecific trait variation aligns with plant age and performance in the context of environmental variation may limit our ability to use traits to infer ecological processes at larger scales.

Methods
We measured leaf physiological and morphological traits, canopy volume, and flowering effort for Artemisia californica (California sagebrush), a …

Effects Of 10 Years Of Fire And Climate Variability On Perennial Grass Cover In Shortgrass Steppe, P. L. Ford

IGC Proceedings (1977-2023)

No abstract provided.

Gross Biomass And Root/Shoot Ratio Mediated Drought Sensitivities Of Ecosystem Carbon Exchange In A Meadow Steppe, Yunbo Wang, Wei Sun, Deli Wang

IGC Proceedings (1977-2023)

According to IPCC’s Report (2007), global precipitation regimes will change largely in the future, with more annual precipitation at the mid-latitude regions. Simultaneously, due to the accelerating industrialization and use of nitrogen (N) fertilizer, significant increase in nitrogen deposition has been widely documented (Liu et al., 2013).

Water and nitrogen are the two most important limiting factors for the ecological processes of arid and semi-arid grassland ecosystems; therefore, altered precipitation regimes and enhanced nitrogen deposition are likely to change vegetation composition, ecosystem productivity, and aboveground vs belowground biomass distribution.

In addition to these long-term changes, short-term climate extremes, such …