Biodiversity of Grasslands

2018 ◽  
Author(s):  
Brian J. Wilsey
Keyword(s):  
Soil Ph ◽  
Conceptual Models ◽  
Strong Predictor ◽  
Seed Mass ◽  
Bird Species ◽  
Leaf Traits ◽  
Acidic Soils ◽  
Grassland Species ◽  
Mammalian Herbivores ◽  
Foregut Fermentation

Grasslands can be surprisingly diverse and contain many charismatic flora and fauna. Plant species are often combined into functional groups. Three major conceptual models: competitors-stress tolerants-ruderals (CSR); the leaf traits, plant height, seed mass (LHS); and R*, used to classify grassland species are described by the author. There are three distinct groups of mammalian herbivores based on the ways that herbivores harbor cellulose degrading microbes: hindgut fermentation, foregut fermentation, and foregut fermentation with rumination. Grasslands have a smaller number of bird species than forested systems, and the bird species that are endemic to grasslands tend to be specialized to open habitat (e.g., large flightless birds). Abundant insects can gathered into feeding groups. Single-celled organisms are important in grassland nutrient cycling and as mutualists and pathogens and are extremely abundant in soil. Soil pH is a strong predictor of bacterial diversity (as in plants), with diversity higher in neutral than in acidic soils.

scholarly journals Plant Species-Dependent Effects of Liming and Plant Residue Incorporation on Soil Bacterial Community and Activity in an Acidic Orchard Soil

2020 ◽  
Vol 10 (16) ◽  
pp. 5681
Author(s):  
Xiaodi Liu ◽  
Zengwei Feng ◽  
Yang Zhou ◽  
Honghui Zhu ◽  
Qing Yao
Keyword(s):  
Microbial Community ◽  
Organic Carbon ◽  
Community Composition ◽  
Plant Species ◽  
Soil Ph ◽  
Microbial Community Composition ◽  
Plant Residue ◽  
Acidic Soils ◽  
Residue Incorporation ◽  
Test Plants

Both liming and plant residue incorporation are widely used practices for the amelioration of acidic soils—however, the difference in their effects is still not fully understood, especially regarding the microbial community. In this study, we took the acidic soils from a subtropical orchard as target soils, and implemented liming and plant residue incorporation with a leguminous and a gramineous cover crop as test plants. After six months of growth, soil pH, total organic carbon (TOC), dissolved organic carbon (DOC) and nutrient contents were determined, soil enzymes involving C, N, P cycling were assayed, and microbial communities were also analyzed using Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE). Results showed that liming was more effective in elevating soil pH, while plant residue incorporation exerted a more comprehensive influence—not only on soil pH, but also on soil enzyme activity and microbial community. PCR-DGGE analysis revealed that liming changed the microbial community structure more greatly than plant residue incorporation, while plant residue incorporation altered the microbial community composition much more than liming. The growth responses of test plants to liming and plant residue incorporation depended on plant species, indicating the necessity to select appropriate practice for a particular crop. A further, detailed investigation into the microbial community composition, and the respective functions using metagenomic approach, is also suggested.

scholarly journals Predicting Leaf Trait Variability as a Functional Descriptor of the Effect of Climate Change in Three Perennial Grasses

Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 233
Author(s):  
Marwa Hamdani ◽  
Khouloud Krichen ◽  
Mohamed Chaieb
Keyword(s):  
Functional Traits ◽  
Leaf Traits ◽  
Perennial Grasses ◽  
Arid Ecosystems ◽  
Leaf Trait ◽  
Grassland Species ◽  
Dimensional Shrinkage ◽  
Potential Link ◽  
Dehydration Avoidance ◽  
Stipa Lagascae

Aims of the study: The most important trends of the current climate variability is the scarcity of rains that affects arid ecosystems. The aim of this study was to explore the variability of leaf functional traits by which grassland species survive and resist drought and to investigate the potential link between resource use efficiency and water scarcity resistance strategies of species. Methods: Three grasses (Cenchrus ciliaris (C4), Stipa parviflora and Stipa lagascae (C3)) were established in a randomized block consisting of eleven replications. The seedlings were kept under increasing levels of water stress. In addition to their functional leaf traits, the rate of water loss and dimensional shrinkage were also measured. Key Results: Thicker and denser leaves, with higher dry matter contents, low specific leaf area and great capacity of water retention are considered among the grasses’ strategies of dehydration avoidance. Significant differences between the means of the functional traits were obtained. Furthermore, strong correlations among leaf traits were also detected (Spearman’s r exceeding 0.8). Conclusions: The results provide evidence that the studied grasses respond differently to drought by exhibiting a range of interspecific functional strategies that may ameliorate the resilience of grassland species communities under extreme drought events.

scholarly journals Links between Ammonia Oxidizer Community Structure, Abundance, and Nitrification Potential in Acidic Soils

2011 ◽  
Vol 77 (13) ◽  
pp. 4618-4625 ◽  
Author(s):  
Huaiying Yao ◽  
Yangmei Gao ◽  
Graeme W. Nicol ◽  
Colin D. Campbell ◽  
James I. Prosser ◽  
...  
Keyword(s):  
Community Structure ◽  
Soil Ph ◽  
Ammonia Oxidation ◽  
Environmental Drivers ◽  
Ammonia Oxidizer ◽  
Long Term Effects ◽  
Acidic Soils ◽  
Nitrification Potential ◽  
Potential Nitrification ◽  
Orchard Soils

ABSTRACTAmmonia oxidation is the first and rate-limiting step of nitrification and is performed by both ammonia-oxidizing archaea (AOA) and bacteria (AOB). However, the environmental drivers controlling the abundance, composition, and activity of AOA and AOB communities are not well characterized, and the relative importance of these two groups in soil nitrification is still debated. Chinese tea orchard soils provide an excellent system for investigating the long-term effects of low pH and nitrogen fertilization strategies. AOA and AOB abundance and community composition were therefore investigated in tea soils and adjacent pine forest soils, using quantitative PCR (qPCR), terminal restriction fragment length polymorphism (T-RFLP) and sequence analysis of respective ammonia monooxygenase (amoA) genes. There was strong evidence that soil pH was an important factor controlling AOB but not AOA abundance, and the ratio of AOA to AOBamoAgene abundance increased with decreasing soil pH in the tea orchard soils. In contrast, T-RFLP analysis suggested that soil pH was a key explanatory variable for both AOA and AOB community structure, but a significant relationship between community abundance and nitrification potential was observed only for AOA. High potential nitrification rates indicated that nitrification was mainly driven by AOA in these acidic soils. Dominant AOAamoAsequences in the highly acidic tea soils were all placed within a specific clade, and one AOA genotype appears to be well adapted to growth in highly acidic soils. Specific AOA and AOB populations dominated in soils at particular pH values and N content, suggesting adaptation to specific niches.

scholarly journals Response of Fungal Diversity, Community Composition, and Functions to Nutrients Management in Red Soil

2021 ◽  
Vol 7 (7) ◽  
pp. 554
Author(s):  
Muhammad Atif Muneer ◽  
Xiaoman Huang ◽  
Wei Hou ◽  
Yadong Zhang ◽  
Yuanyang Cai ◽  
...  
Keyword(s):  
Community Composition ◽  
Soil Ph ◽  
Fungal Diversity ◽  
Management Practices ◽  
Nutrient Management ◽  
Critical Role ◽  
Red Soil ◽  
Plant Performance ◽  
Fungal Communities ◽  
Acidic Soils

Soil fungi play a critical role in plant performance and soil nutrient cycling. However, the understanding of soil fungal community composition and functions in response to different nutrients management practices in red soils remains largely unknown. Here, we investigated the responses of soil fungal communities and functions under conventional farmer fertilization practice (FFP) and different nutrient management practices, i.e., optimization of NPK fertilizer (O) with soil conditioner (O + C), with lime and mushroom residue (O + L + M), and with lime and magnesium fertilizer (O + L + Mg). Illumina high-throughput sequencing was used for fungal identification, while the functional groups were inferred with FUNGuild. Nutrient management practices significantly raised the soil pH to 4.79–5.31 compared with FFP (3.69), and soil pH had the most significant effect (0.989 ***) on fungal communities. Predominant phyla, including Ascomycota, Basidiomycota, and Mortierellomycota were identified in all treatments and accounted for 94% of all fungal communities. The alpha diversity indices significantly increased under nutrients management practices compared with FFP. Co-occurrence network analysis revealed the keystone fungal species in the red soil, i.e., Ascomycota (54.04%), Basidiomycota (7.58%), Rozellomycota (4.55%), and Chytridiomycota (4.04%). FUNGuild showed that the relative abundance of arbuscular mycorrhizal fungi and ectomycorrhizal fungi was higher, while pathogenic fungi were lower under nutrient management practices compared with FFP. Our findings have important implications for the understanding of improvement of acidic soils that could significantly improve the soil fungal diversity and functioning in acidic soils.

scholarly journals Variation in pH Optima of Hydrolytic Enzyme Activities in Tropical Rain Forest Soils

2010 ◽  
Vol 76 (19) ◽  
pp. 6485-6493 ◽  
Author(s):  
Benjamin L. Turner
Keyword(s):  
Soil Ph ◽  
Forest Soils ◽  
Extracellular Enzymes ◽  
Hydrolytic Enzyme ◽  
Hydrolytic Enzymes ◽  
Acidic Ph ◽  
Acidic Soils ◽  
Fluorogenic Substrates ◽  
Ph Values ◽  
Optimum Ph

ABSTRACT Extracellular enzymes synthesized by soil microbes play a central role in the biogeochemical cycling of nutrients in the environment. The pH optima of eight hydrolytic enzymes involved in the cycles of carbon, nitrogen, phosphorus, and sulfur, were assessed in a series of tropical forest soils of contrasting pH values from the Republic of Panama. Assays were conducted using 4-methylumbelliferone-linked fluorogenic substrates in modified universal buffer. Optimum pH values differed markedly among enzymes and soils. Enzymes were grouped into three classes based on their pH optima: (i) enzymes with acidic pH optima that were consistent among soils (cellobiohydrolase, β-xylanase, and arylsulfatase), (ii) enzymes with acidic pH optima that varied systematically with soil pH, with the most acidic pH optima in the most acidic soils (α-glucosidase, β-glucosidase, and N-acetyl-β-glucosaminidase), and (iii) enzymes with an optimum pH in either the acid range or the alkaline range depending on soil pH (phosphomonoesterase and phosphodiesterase). The optimum pH values of phosphomonoesterase were consistent among soils, being 4 to 5 for acid phosphomonoesterase and 10 to 11 for alkaline phosphomonoesterase. In contrast, the optimum pH for phosphodiesterase activity varied systematically with soil pH, with the most acidic pH optima (3.0) in the most acidic soils and the most alkaline pH optima (pH 10) in near-neutral soils. Arylsulfatase activity had a very acidic optimum pH in all soils (pH ≤3.0) irrespective of soil pH. The differences in pH optima may be linked to the origins of the enzymes and/or the degree of stabilization on solid surfaces. The results have important implications for the interpretation of hydrolytic enzyme assays using fluorogenic substrates.

The effect of soil pH on persistence of seeds of grassland species in soil

Plant Ecology ◽  
2015 ◽  
Vol 216 (8) ◽  
pp. 1163-1175 ◽  
Author(s):  
Sofía Basto ◽  
Ken Thompson ◽  
Mark Rees
Keyword(s):  
Soil Ph ◽  
Grassland Species

scholarly journals Avian Responses to Post Oak Savanna Restoration in Eastern Texas

2021 ◽  
Author(s):  
Courtney McInnerney ◽  
Brian Oswald ◽  
Chris Comer ◽  
Roger J. Masse ◽  
Christopher M. Schalk
Keyword(s):  
Tallgrass Prairie ◽  
Bird Species ◽  
The United States ◽  
Oak Savanna ◽  
Breeding Bird ◽  
Grassland Species ◽  
Post Oak ◽  
Oak Savannas ◽  
Chondestes Grammacus ◽  
Post Oak Savanna

In response to the loss and degradation of oak savannas, associated wildlife populations have experienced long-term declines. For example, 70% of disturbance-dependent bird species in the United States have experienced declines with most of these species being associated with grasslands, oak savannas, and open forest communities. Few studies have documented the success of restoration in post oak savanna systems in regard to breeding bird assemblages. Our objective was to quantify avian abundance, density, species richness, and assemblage structure in restored post oak savannas at Gus Engeling Wildlife Management Area (GEWMA) in Eastern Texas. We conducted vegetation and avian transect surveys post-restoration (2016-2017) and compared our results to pre-restoration baseline surveys conducted in 2009. Restoration conducted in 2010 was partially successful, with vegetation changes that closely resemble historical characteristics. The avian assemblage also showed indications of successful restoration, with the appearance of obligate grassland species following restoration efforts. Specifically, pre-restoration, one dickcissel ( Spiza americana ) and no lark sparrows ( Chondestes grammacus ) were detected. By 2017, dickcissel density in the restored sites was similar to densities recorded on tallgrass prairie and other high-quality habitat in the southern portion of its range. Lark sparrows were also detected, but at low densities. We also observed the persistence and/or increase of several woodland and open woodland species over time. These patterns are likely attributed to the creation of a mosaic of suitable microhabitats preferred by these species such as the persistence of mottes as well as their increased edge-to-area ratios. Restoration sites that are larger in size and in closer proximity to other restored or remnant savannas should have a higher priority to increase their likelihood of recolonization by target species. Restoration efforts may still be successful in more isolated areas, such as GEWMA, but post-restoration monitoring should be conducted and reported to provide insights regarding site-specific restoration dynamics.

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