scholarly journals Limits to resilience of Afroalpine vegetation to grazing and burning: a case study of grasses from the Drakensberg Mountain Centre, southern Africa

2021 ◽  
Author(s):  
Steven P. Sylvester ◽  
Robert J. Soreng ◽  
Aluoneswi C. Mashau ◽  
Mitsy D.P.V. Sylvester ◽  
Anthony Mapaura ◽  
...  
Keyword(s):  
Management Practices ◽  
Fire Regimes ◽  
Taxonomic Diversity ◽  
Grass Species ◽  
Natural State ◽  
Mean Annual Temperature ◽  
List Type ◽  
Heavy Grazing ◽  
Bioclimatic Variables ◽  
Main Influence

AbstractHigh-elevation Afroalpine ecosystems of the Drakensberg Mountain Centre (DMC) of Lesotho and South Africa, renowned for their high endemism and key ecosystem services, are socio-ecological systems that have seen human activity for millennia. However, their responses to land management practices are understudied. Controversy over their natural state has also led to conflicting policies and management emphases.Focusing on the crucial ecosystem-modulating component, grasses (Poaceae), we evaluate the response of DMC Afroalpine vegetation to human impact through grazing and burning. Grass species associations were recorded from grassland, shrubland and wetland-riparian-seep ecotypes across a range of grazing and fire regimes to document relationships between abiotic conditions, disturbance, and taxonomic diversity and composition.CCA of grass community composition retrieved a large cluster of plots of mixed grazing and burning regimes with no particular environmental vector correlated with them. Other smaller groups of plots separated from these were associated to heavy grazing, bioclimatic variables, slope gradient, and aspect. Indicator species analyses found DMC endemic grasses were associated to low grazing, while alien grasses were associated to heavy grazing. GLMs found little difference between ecotype-disturbance categories with regards plant species richness, mean alpha hull=2 range-size of native and sub-Saharan endemic grasses, and site-level Sørensen beta diversity (βsor). Some differences were noted, including the highest cover and proportion of DMC endemics being found in low-grazed grassland, and highest cover and proportion of alien grasses and highest plot-level βsor being found in heavily grazed ecotypes. Relative importance analyses found grazing regime to be the main influence on cover and proportion of DMC endemic and alien grasses. Partial Mantel tests found mean annual temperature and grazing regime to be the main influence on plot-level βsor.Synthesis: Taxonomic diversity and composition of DMC Afroalpine grasslands was relatively unaffected by moderate grazing and intense burning, although heavy grazing had a largely detrimental impact, with its ubiquity across the DMC a major cause for concern. High levels of endemism, coupled with the above data emphasizing the robustness of DMC grasslands to disturbance, also supports Afroalpine grasslands as a natural component of the DMC. This research reinforces the natural grass-dominated nature of the DMC as a social-ecological system where sustainable management is possible thanks to its resilience to grazing and burning, although current widespread overgrazing requires urgent attention.

scholarly journals Invasive grasses in South Texas rangelands: historical perspectives and future directions

2020 ◽  
Vol 13 (2) ◽  
pp. 41-58
Author(s):  
Justin P. Wied ◽  
Humberto L. Perotto-Baldivieso ◽  
April A. T. Conkey ◽  
Leonard A. Brennan ◽  
José M. Mata
Keyword(s):  
Remote Sensing ◽  
Management Practices ◽  
Fire Regimes ◽  
South Texas ◽  
Grass Species ◽  
Forage Production ◽  
Bothriochloa Ischaemum ◽  
Heteropogon Contortus ◽  
Historical Perspectives ◽  
Sensing Applications

AbstractSouth Texas is home to a high diversity of species due to its location at the confluence of subtropical, desert, and coastal ecoregions. Historical overgrazing of South Texas rangelands transformed the savanna and prairie to a landscape dominated by woody plants and shrubs interspersed with low seral grass species and bare ground. During the first half of the 20th century, exotic grass species, coupled with the application of industrial agricultural practices appeared to be the future of forage production in South Texas and elsewhere. Several of these exotic species, namely King Ranch bluestem [Bothriochloa ischaemum (L.) Keng], Kleberg bluestem [Dichanthium annulatum (Forssk.) Stapf], Angelton bluestem [Dichanthium aristatum (Poir.) C.E. Hubbard], buffelgrass [Pennisetum ciliare (L.) Link], guineagrass [Urochloa maxima (Jacq.) R. Webster], Lehmann lovegrass (Eragrostis lehmanniana Nees), and Bermudagrass [Cynodon dactylon (L.) Pers.], have escaped pasture cultivation. Additionally, the native grass tanglehead [Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult.] has begun displaying invasive behaviors. The monoculture growth habit of these species simplifies vegetation structure, reduces biodiversity, and decreases habitat for many species of wildlife. These grasses also alter natural fire regimes and nutrient cycling. This landscape-level transformation of vegetation composition and structure requires monitoring to quantify and assess the spatial and temporal distributions of invasive species as a basis to inform management practices. Current advances in remote sensing technologies, such as very high spatial resolution coupled with daily satellite imagery and unmanned aerial vehicles, are providing tools for invasive vegetation monitoring. We provide a synthesis of the natural history of these grasses, including their introductions, an overview of remote sensing applications in South Texas, and recommendations for future management practices.

scholarly journals Phylogenetic diversity efficiently and accurately prioritizes the conservation of aquatic macroinvertebrate communities

2019 ◽  
Author(s):  
Kathryn M. Weglarz ◽  
W. Carl Saunders ◽  
Andrew Van Wagenen ◽  
William D. Pearse
Keyword(s):  
Phylogenetic Diversity ◽  
Management Practices ◽  
Freshwater Ecosystems ◽  
Environmental Drivers ◽  
Mean Annual Temperature ◽  
List Type ◽  
Ecosystem Structure ◽  
Macroinvertebrate Communities ◽  
Road Density ◽  
Management Actions

AbstractLand degradation is a leading cause of biodiversity loss yet its consequences on freshwater ecosystems are poorly understood, exacerbating difficulties with assessing ecosystem quality and the effectiveness of restoration practices.Many monitoring programs rely on macroinvertebrates to assess the biotic effects of degradation and/or restoration and management actions on freshwater ecosystems. The ratio of Observed (O) to Expected (E) macroinvertebrate taxa at a given site—O/E—is often used for this purpose, despite the amount of modeling and data required to generate expectations and difficulties quantitatively assessing the degree of degradation at a site.Despite widespread use in academic biology, phylogenetic diversity is rarely applied in management, regardless of empirical correlations between phylogenetic diversity and management targets such as ecosystem structure and function.We use macroinvertebrate data from 1,400 watersheds to evaluate the potential for phylogenetic metrics to inform evaluations of management practices. These data have been collected since 1998, and have been used to determine the effectiveness of conservation management for the maintenance and restoration of riparian and aquatic systems.Phylogenetic diversity detected degradation as effectively as O/E, despite not having baseline ‘expectation’ data. Site disturbance, road density, and broader environmental drivers such as mean annual temperature strongly predicted site phylogenetic diversity, providing concrete management objectives to increase site health.Synthesis and applications. Management efforts targeted solely at taxonomic metrics, such as O/E, have been successfully used to manage sites. We show here that phylogenetic diversity metrics can support such efforts by providing additional information about the kind of species at sites. Given the ease with which such approaches can be applied, we call on others to use them to supplement existing prioritization schemes.

scholarly journals Innovative Extension Methods in the U.S. to Promote Irrigation Water Management

2020 ◽  
Vol 63 (5) ◽  
pp. 1549-1558
Author(s):  
Daran R. Rudnick ◽  
Matt Stockton ◽  
Saleh Taghvaeian ◽  
Jason Warren ◽  
Michael D. Dukes ◽  
...  
Keyword(s):  
Water Management ◽  
Experiential Learning ◽  
Best Management Practices ◽  
Irrigation Water ◽  
Management Practices ◽  
New Technology ◽  
List Type ◽  
Extension Programs ◽  
Irrigation Water Management ◽  
Primary Means

HIGHLIGHTSUniversity extension has been playing a larger role, serving a larger number of irrigated farms.Extension programs in irrigation water management (IWM) have been transitioning away from lectures and field tours as the primary means of knowledge transfer.New IWM programs focus on experiential learning, development of practitioner networks, and industry participation.Abstract. Promotion and adoption of irrigation water management (IWM) technology, tools, and best management practices are important as water availability concerns are addressed. Traditional extension programs have relied on lecture presentations, field tours, fact sheets, and on-station demonstrations to promote IWM practices and tools. However, these platforms tend not to provide the experience and opportunity for growers to identify and become comfortable with innovative solutions, such as new technology. To address these challenges and to appeal to an ever-changing client base, innovative and locally relevant extension and outreach programs have been devised to engage and educate growers. This article describes some of these programs that extend beyond previous traditional programs to connect growers with IWM. Keywords: Demonstrations, Experiential learning, Grower competition, Outreach, Practitioner networks.

Carbon stocks in Tasmanian soils

Soil Research ◽  
2012 ◽  
Vol 50 (2) ◽  
pp. 83 ◽  
Author(s):  
W. E. Cotching
Keyword(s):  
Management Practices ◽  
Agricultural Soils ◽  
C Sequestration ◽  
Mean Annual Temperature ◽  
Soil C ◽  
C Stocks ◽  
Initial Soil ◽  
If Current ◽  
Intensive Cropping ◽  
The Difference

Soil carbon (C) stocks were calculated for Tasmanian soil orders to 0.3 and 1.0 m depth from existing datasets. Tasmanian soils have C stocks of 49–117 Mg C/ha in the upper 0.3 m, with Ferrosols having the largest soil C stocks. Mean soil C stocks in agricultural soils were significantly lower under intensive cropping than under irrigated pasture. The range in soil C within soil orders indicates that it is critical to determine initial soil C stocks at individual sites and farms for C accounting and trading purposes, because the initial soil C content will determine if current or changed management practices are likely to result in soil C sequestration or emission. The distribution of C within the profile was significantly different between agricultural and forested land, with agricultural soils having two-thirds of their soil C in the upper 0.3 m, compared with half for forested soils. The difference in this proportion between agricultural and forested land was largest in Dermosols (0.72 v. 0.47). The total amount of soil C in a soil to 1.0 m depth may not change with a change in land use, but the distribution can and any change in soil C deeper in the profile might affect how soil C can be managed for sequestration. Tasmanian soil C stocks are significantly greater than those in mainland states of Australia, reflecting the lower mean annual temperature and higher precipitation in Tasmania, which result in less oxidation of soil organic matter.

Effect of fire regime on the grass community of the humid savanna of Lamto, Ivory Coast

2018 ◽  
Vol 35 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Kouamé Fulgence Koffi ◽  
Aya Brigitte N’Dri ◽  
Jean-Christophe Lata ◽  
Souleymane Konaté ◽  
Tharaniya Srikanthasamy ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Ivory Coast ◽  
Fire Regime ◽  
Fire Regimes ◽  
Abundant Species ◽  
Grass Species ◽  
The Third ◽  
Humid Savanna ◽  
The Impact ◽  
Tussock Grasses

AbstractThis study assesses the impact of four fire treatments applied yearly over 3 y, i.e. early fire, mid-season fire, late fire and no fire treatments, on the grass communities of Lamto savanna, Ivory Coast. We describe communities of perennial tussock grasses on three replicated 5 × 5-m or 10 × 5-m plots of each fire treatment. Tussock density did not vary with fire treatment. The relative abundance of grass species, the circumference of grass tussocks and the probability of having a tussock with a central die-back, varied with fire treatment. Mid-season fire had the highest proportion of tussocks with a central die-back while the late fire had the smallest tussocks. Tussock density, circumference, relative abundance and probability of having a central die-back varied with species. Andropogon canaliculatus and Hyparrhenia diplandra were the most abundant of the nine grass species. They had the largest tussocks and the highest proportion of tussock with a central die-back. Loudetia simplex was the third most abundant species but was very rare in no fire plots. The distribution of tussock circumferences was right skewed and dominated by small tussocks. The proportion of the tussocks with a central die-back strongly increased with circumference, which could lead to tussock fragmentation. Taken together, this study suggests that fire regimes impact grass demography and that this impact depends on grass species and tussock size.

scholarly journals Metabarcoding reveals different zooplankton communities in northern and southern areas of the North Sea

2020 ◽  
Author(s):  
Jan Niklas Macher ◽  
Berry B. van der Hoorn ◽  
Katja T. C. A. Peijnenburg ◽  
Lodewijk van Walraven ◽  
Willem Renema
Keyword(s):  
North Sea ◽  
Zooplankton Community ◽  
Taxonomic Diversity ◽  
Molecular Techniques ◽  
Trophic Levels ◽  
List Type ◽  
The North ◽  
Shelf Sea ◽  
The North Sea ◽  
Zooplankton Communities

AbstractZooplankton are key players in marine ecosystems, linking primary production to higher trophic levels. The high abundance and high taxonomic diversity renders zooplankton ideal for biodiversity monitoring. However, taxonomic identification of the zooplankton assemblage is challenging due to its high diversity, subtle morphological differences and the presence of many meroplanktonic species, especially in coastal seas. Molecular techniques such as metabarcoding can help with rapid processing and identification of taxa in complex samples, and are therefore promising tools for identifying zooplankton communities. In this study, we applied metabarcoding of the mitochondrial cytochrome c oxidase I gene to zooplankton samples collected along a latitudinal transect in the North Sea, a shelf sea of the Atlantic Ocean. Northern regions of the North Sea are influenced by inflow of oceanic Atlantic waters, whereas the southern parts are characterised by more coastal waters. Our metabarcoding results indicated strong differences in zooplankton community composition between northern and southern areas of the North Sea, particularly in the classes Copepoda, Actinopterygii (ray-finned fishes) and Polychaeta. We compared these results to the known distributions of species reported in previous studies, and by comparing the abundance of copepods to data obtained from the Continuous Plankton Recorder (CPR). We found that our metabarcoding results are mostly congruent with the reported distribution and abundance patterns of zooplankton species in the North Sea. Our results highlight the power of metabarcoding to rapidly assess complex zooplankton samples, and we suggest that the technique could be used in future monitoring campaigns and biodiversity assessments.HighlightsZooplankton communities are different in northern and southern areas of the North SeaMetabarcoding results are consistent with known species distributions and abundanceMetabarcoding allows for fast identification of meroplanktonic species

scholarly journals Impact of Planter Closing Wheels on Corn Emergence in No-Till Systems

2020 ◽  
Vol 36 (5) ◽  
pp. 727-732
Author(s):  
Jessica L Drewry ◽  
Brian D. Luck ◽  
Francisco J. Arriaga
Keyword(s):  
Cover Crops ◽  
Management Practices ◽  
Side Wall ◽  
List Type ◽  
No Till ◽  
Energy Inputs ◽  
Soil Temperatures ◽  
Plant Emergence ◽  
Rate Of Emergence ◽  
Set Up

HighlightsAftermarket closing wheels increased corn emergence by 2% over standard rubber wheels.Yield was not significant by closing wheel type.Abstract. Producers are increasingly adopting cover crops and no-till planting for a variety of reasons including improving soil fertility and reducing energy inputs. However, adopting these practices may require changes in equipment and management strategy; therefore, research is needed to develop best practices for producers to reduce the risk and encourage adoption. The use of aftermarket closing wheels has been cited as a method to improve emergence under no-till conditions as preparing an ideal seedbed can be more difficult under these conditions due to limited seed-soil contact and side wall compaction. The effect of three aftermarket and the standard rubber closing wheels on emergence and yield under no-till planting of corn into heavy crop residue or cover crops was measured at three Wisconsin locations using a randomized complete block experimental design. Soil temperature and moisture was also monitored during the growing season. Corn plant emergence was measured at least three times to estimate the rate of emergence as a function of growing degree units using air and soil temperatures. The final emergence of corn planted with an aftermarket wheel was found to be significantly higher than the standard rubber closing wheel (p=0.069, a=0.1) across all locations. Yield was not found to be significant by wheel type most likely due to differences in field history and in season management practices. Keywords: Closing wheel, Cover crop, Emergence, No-till, Planter set-up.

scholarly journals 4162 Improving Data Capacity and Predictive Capability of NSQIP-P Using Designed Sampling from Databases

2020 ◽  
Vol 4 (s1) ◽  
pp. 137-138
Author(s):  
Martha-Conley Ingram ◽  
Yao Tian ◽  
Sanjay Mehrotra ◽  
Dan Apley ◽  
Mehul V Raval
Keyword(s):  
Data Collection ◽  
Management Practices ◽  
Patient Reported Outcome Measures ◽  
Population Based ◽  
List Type ◽  
Statistical Regression ◽  
Surgical Quality ◽  
Improvement Project ◽  
Patient Reported ◽  
Study Population

OBJECTIVES/GOALS: Designed sampling from databases (DSD) methods have been used to cross-check electronic medical records for errors, structure study design, and, we hypothesize, can be used to make data collection for surgical quality metrics more efficient, particularly within national databases. We plan to apply statistical and DSD methods to accomplish the following aims: 1.Identify the most important elements in managing post-operative pain2.Identify the most informative procedure or population-based targets to focus collection of additional, labor-intense detail surrounding adequacy of pain control (i.e., Patient Reported Outcome Measures (PROMs)).METHODS/STUDY POPULATION: Our study population includes all children, ages 1-18 years, captured in the National Surgical Quality Improvement Project-Pediatric (NSQIP-P) from 2019 to 2021. We plan to apply statistical (regression modeling) and DSD methods to accomplish the aims listed above. RESULTS/ANTICIPATED RESULTS: For Aim 1, we expect to identify patient, procedure, and perioperative pain management practices that influence postoperative pain. For Aim 2, we will focus on outcomes such as PROMs that are challenging to obtain. By applying DSD methods, we will identify specific procedure and/or population-based cohorts to capture PROMs and decrease data collection burdens, while maintaining power, as the project is scaled nationally to all of NSQIP-P. DISCUSSION/SIGNIFICANCE OF IMPACT: Data from this study will inform expansion of NSQIP-P to collect novel outcomes of clinical and societal importance without prohibitively increasing data collection burden.

Climatic modelling of the distribution of the mahogany glider (Petaurus gracilis), and the squirrel glider (P. norfolcensis)

1999 ◽  
Vol 47 (1) ◽  
pp. 47 ◽  
Author(s):  
Stephen M. Jackson ◽  
Andrew Claridge
Keyword(s):  
Computer Program ◽  
Geographic Area ◽  
Annual Precipitation ◽  
Mean Annual Temperature ◽  
Moisture Index ◽  
Temperature Range ◽  
Bioclimatic Variables ◽  
Squirrel Glider ◽  
Distributional Limits

Known locality records of the mahogany glider (Petaurus gracilis) and the squirrel glider (Petaurus norfolcensis) in Queensland were used to predict the distributional limits of both of these species within Queensland using the computer program BIOCLIM. The mahogany glider was predicted to occur in areas with a higher average mean annual temperature, smaller temperature range, higher temperatures throughout the year, higher annual precipitation, higher seasonality of precipitation, higher seasonality of moisture index and higher precipitation in the wettest quarter and warmest quarter when compared with the predicted distribution of the squirrel glider. The squirrel glider has been recorded across a wider geographic area and its distribution had a larger variation in bioclimatic variables. The predicted distribution of the mahogany glider did not extend outside the known area on the mainland, although the species was predicted to occur over 500 m elevation in some areas within their known range. BIOCLIM did, however, predict that the mahogany glider might occur on Hinchinbrook Island and the Palm Islands. In contrast to the mahogany glider, the squirrel glider was predicted to occur well outside of its known distribution, including all that area predicted to be habitat for the former species. Despite this predicted overlap, the closest these two species are known to occur to each other is 25 km.

Germination response to heat and smoke of 22 Poaceae species from grassy woodlands

2005 ◽  
Vol 53 (5) ◽  
pp. 445 ◽  
Author(s):  
S. Clarke ◽  
K. French
Keyword(s):  
Heat Treatment ◽  
Species Richness ◽  
Exotic Species ◽  
Fire Regime ◽  
Fire Regimes ◽  
Grass Species ◽  
Percentage Germination ◽  
Germination Response ◽  
Eastern Australia ◽  
Smoke Water

Grasses form an important component of grassy woodlands, although their response to fire has been understudied. In this study, fire germination responses of 22 Poaceae species from an endangered grassy-woodland community in eastern Australia were investigated. Seeds of 20 native and two exotic species were subjected to heat (no heat, 40, 80 and 120°C) and smoke treatment (10% dilution smoke water) and the percentage germination was compared. Germination response of species showed no consistent pattern to phylogeny and was highly variable. Germination in six species was unaffected by the application of heat or smoke. In five species, heat, irrespective of smoke application, influenced germination. Smoke, irrespective of heat treatment, influenced six species. For a further six species, the effect of smoke varied with temperature. These results suggest that fire regimes will influence the recruitment of grass species differentially and maintaining regional species richness is likely to require the maintenance of a heterogeneous fire regime across the landscape.

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