Seasonal Production of Hypogeal Fungal Sporocarps in a Mixed-Species Eucalypt Forest Stand in South-Eastern Australia

1993 ◽  
Vol 41 (2) ◽  
pp. 145 ◽  
Author(s):  
AW Claridge ◽  
AP Robinson ◽  
MT Tanton ◽  
RB Cunningham
Keyword(s):  
Management Practices ◽  
Morphological Characteristics ◽  
Forest Stand ◽  
Mixed Species ◽  
Probability Of Occurrence ◽  
Soil Variables ◽  
Eucalypt Forest ◽  
Eastern Australia ◽  
Physical Variables ◽  
Over Time

The seasonal production of hypogeal fungal sporoearps was monitored over an 18 month period in a catchment of mixed-species euealypt forest in East Gippsland, Vietoria. During the study, sporocarps of one Ascomycete and 25 Basidiomycete species were collected from soil quadrats sampled sequentially around the bases of eucalypt trees- Sporocarps from these species varied in their dimensions and morphological characteristics. Productivity varied from 21 000 sporocarps ha-1 to 181 000 sporocarps ha-1 or 1.8 kg ha-1 to 8.3 kg ha-1 per month. The probability of occurrence of sporocarps was, on average, greater in midslope sites on a sheltered aspect than elsewhere within the catchment. The number of sporocarps produced varied over time, with a major peak in production occurring during May (late-autumn). This peak occurred mainly within gully sites, which supported on average a greater number of sporocarps than ridge or midslope sites, but a lesser weight of sporocarps. The distribution and productivity (probability of occurrence, number and weight) of sporocarps appeared to be associated with some environmental (soil) variables, but not the physical variables (host tree), that we measured. Sporocarps of some species fruited predominantly in ridge and slope habitats, some species fruited mainly in gullies, whereas others apparently showed no preference for fruiting in ridges, slopes and gullies. Thus, in forest catchments subject to land-management practices such as logging and fire, it may be important to retain undisturbed habitat throughout the topographic sequence to conserve a diversity of hypogeal species.

Changes in soil organic carbon and nitrogen after 47 years with different tillage, stubble and fertiliser management in a Vertisol of north-eastern Australia

Soil Research ◽  
2020 ◽  
Vol 58 (4) ◽  
pp. 346
Author(s):  
K. L. Page ◽  
R. C. Dalal ◽  
S. H. Reeves ◽  
W. J. Wang ◽  
Somasundaram Jayaraman ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Management Practices ◽  
Crop Residues ◽  
Residue Management ◽  
Eastern Australia ◽  
North Eastern ◽  
Over Time

No-till (NT) farming has been widely adopted to assist in reducing erosion, lowering fuel costs, conserving soil moisture and improving soil physical, chemical and biological characteristics. Improvements in soil characteristics are often driven by the greater soil organic matter accumulation (as measured by soil organic carbon (SOC)) in NT compared to conventional tillage (CT) farming systems. However, to fully understand the effect of NT it is important to understand temporal changes in SOC by monitoring over an extended period. We investigated the long-term effect of NT and stubble retention (SR) on changes in SOC and total soil nitrogen (STN) using results from an experiment that has been running for 50 years in a semi-arid subtropical region of north-eastern Australia. In this experiment, the effects of tillage (CT vs NT), residue management (stubble burning (SB) vs SR), and nitrogen (N) fertiliser (0 and 90 kg-N ha–1) were measured in a balanced factorial experiment on a Vertisol (Ustic Pellusert). The use of NT, SR and N fertiliser generally improved SOC (by up to 12.8%) and STN stocks (by up to 31.7%) in the 0–0.1 m layer relative to CT, SB and no N fertiliser, with the greatest stocks observed where all three treatments were used in combination. However, declines in SOC (up to 20%) and STN (up to 25%) occurred in all treatments over the course of the experiment, indicating that changes in management practices were unable to prevent a loss of soil organic matter over time in this farming system. However, the NT and SR treatments did lose less SOC than CT and SB treatments, and SR also reduced STN loss. The δ13C analysis of samples collected in 2008 and 2015 highlighted that crop residues have significantly contributed to SOC stocks at the site and that their contribution is increasing over time.

On the photoreactivity of some hardwood species studied by their leaf characteristics

1970 ◽  
Vol 23 ◽  
Author(s):  
M. Van Miegroet
Keyword(s):  
Morphological Characteristics ◽  
Vegetation Period ◽  
Forest Stand ◽  
Light Environment ◽  
Light Radiation ◽  
Light Conditions ◽  
Site Factors ◽  
Leaf Characteristics ◽  
Single Tree ◽  
Changing Light

A  certain number of measurable characteristics of tree leaves (morphological  characteristics, absorption of light radiation, intensity of respiration and  photosynthesis) are clearly linked with the presence of physiologically  active pigments in the leaves.     Leaf characteristics are highly and inequally influenced by changing  conditions of light environment, especially those related to light intensity,  light quality and duration of the daily illumination period. These  modifications do not only apply to light radiation as created under  laboratory conditions, but also to light conditions ensuing from the place in  the crown of a single tree, the social position of the tree in a forest stand  and the site factors in general.     There are also changes taking place due to the progression of the  vegetation period, at the end of which all species are less tolerant or more  light demanding. The reaction of the leaves towards light radiation out of  different regions of the spectrum is also different. The so-called blue light  radiation (λmax = 440 nm) seems to be of the greatest importance in this  relation, as species react quite different to its action.     The biggest variation in leaf characteristics due to changing light  environment was measured for oak and beech, which both react quickly and are  qualified as 'photolabile species'. No important variations occur in leaves  of ash and maple, which therefore are qualified as 'photostable species'.      As a consequence of variable reactions to changing light conditions, the  relationships between the species are continually modified, even in such a  way that their potential for dominance is not constant.     The classical division into tolerant and intolerant species or  classification of the species based upon the degree of light demand, is  highly inaccurate and it seems preferable to speak of relative light demands  and relative tolerance. All these observations and conclusions bring about a  clear confirmation of the necessity to recognize the individuality of the  single tree, the special character of each growth condition, the own  structure of each forest stand, the specific reaction to one sided  modifications of environmental factors. This is especially important for an  intensive sylvicultural practice.     They also prove the necessity for more physiological and biochemical  research to arrive at a better understanding of growth and its mechanism.      Sylviculture in fact must try to regulate, on an expanded scale, the  phenomens of growth, which is the exchange, absorption and transformation of  energy.     A practical interpretation and regulation of fundamental laws of physiology  and growth will be possible as soon as a clinical form of sylviculture is  created and the adequate instrumentarium developed.

Droughts, floods and freshwater ecosystems: evaluating climate change impacts and developing adaptation strategies

2011 ◽  
Vol 62 (3) ◽  
pp. 223 ◽  
Author(s):  
Allison Aldous ◽  
James Fitzsimons ◽  
Brian Richter ◽  
Leslie Bach
Keyword(s):  
Climate Change ◽  
Case Studies ◽  
Management Practices ◽  
Climate Adaptation ◽  
Numerical Models ◽  
Climate Change Impacts ◽  
Freshwater Ecosystems ◽  
Adaptation Strategies ◽  
South Eastern ◽  
Eastern Australia

Climate change is expected to have significant impacts on hydrologic regimes and freshwater ecosystems, and yet few basins have adequate numerical models to guide the development of freshwater climate adaptation strategies. Such strategies can build on existing freshwater conservation activities, and incorporate predicted climate change impacts. We illustrate this concept with three case studies. In the Upper Klamath Basin of the western USA, a shift in land management practices would buffer this landscape from a declining snowpack. In the Murray–Darling Basin of south-eastern Australia, identifying the requirements of flood-dependent natural values would better inform the delivery of environmental water in response to reduced runoff and less water. In the Savannah Basin of the south-eastern USA, dam managers are considering technological and engineering upgrades in response to more severe floods and droughts, which would also improve the implementation of recommended environmental flows. Even though the three case studies are in different landscapes, they all contain significant freshwater biodiversity values. These values are threatened by water allocation problems that will be exacerbated by climate change, and yet all provide opportunities for the development of effective climate adaptation strategies.

Changes in the contents of corporate codes of ethics: an institutional interpretation

2015 ◽  
Vol 27 (4) ◽  
pp. 369-388 ◽  
Author(s):  
Jang B. Singh
Keyword(s):  
Design Methodology ◽  
Management Practices ◽  
A Priori ◽  
Codes Of Ethics ◽  
Legal Authority ◽  
Valuable Contribution ◽  
Content Type ◽  
Innovative Management ◽  
Study Population ◽  
Over Time

Purpose – The purpose of this paper was to examine changes in the contents of Canadian corporate codes of ethics over a period of two decades from an institutionalization perspective. Design/methodology/approach – The paper tracks changes in the contents of the codes of large Canadian corporations longitudinally by analyzing their contents at two points over two decades, in 1992 and 2012. In particular, the paper tests three hypotheses related to the institutionalization of codes. Findings – It was found that the codes have become more prescriptive, they are more concerned with social responsibility and are more likely to identify their moral and legal authority. Overall, the findings support an institutional interpretation of the observed changes. Research limitations/implications – While large corporations are critical in establishing new and innovative management practices, their selection as the study population limits the generalizabilty of the findings. Another limitation of this paper is that it used an a priori determined set of items to analyze the contents of the codes and while this was needed to facilitate the comparison across time, it also meant that some important items were not clearly identified. Originality/value – Codes of ethics are the foundation of ethics programs in corporations and their contents could be critical in the development of a culture of ethics in corporations. This paper makes a valuable contribution to research on business ethics by analyzing the codes of ethics of the largest corporations in Canada at two points over two decades. The need to track changes in corporate codes of ethics over time has been advocated by several researchers, but longitudinal studies in this area are rare.

scholarly journals Has Carbon Disclosure Become More Transparent in the Global Logistics Industry? An Investigation of Corporate Carbon Disclosure Strategies between 2010 and 2015

Logistics ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 13 ◽  
Author(s):  
David M. Herold
Keyword(s):  
Management Practices ◽  
Logistics Industry ◽  
Carbon Management ◽  
Related Information ◽  
External Pressures ◽  
Global Logistics ◽  
Disclosure Responses ◽  
Stakeholder Pressures ◽  
Over Time

Global logistics companies are increasingly disclosing carbon related information due to institutional and stakeholder pressures. Existing research, however, is limited to categorizing these pressures and their influences on corporate carbon disclosure strategies. In particular, literature to date has not distinguished between different carbon disclosure strategies and how they may have changed over time. In response, this paper: (1) proposes a framework that depicts four different carbon disclosure responses and strategies based on internal and external pressures; and (2) subsequently analyzes and compares corporate carbon disclosure strategies between 2010 and 2015. Using a sample of 39 leading global logistics companies, carbon disclosure strategies are categorized based on the analysis of 25 applied carbon management practices from Bloomberg ESG to see if carbon management practices and the associated strategies have changed. The findings show overall shifts to more transparent corporate carbon disclosure strategies between 2010 and 2015 with an increase of applied carbon management practices in both internal and external actions.

scholarly journals Fire severity and ecosystem resilience – lessons from the Wombat Fire Effects Study (1984-2003)

2012 ◽  
Vol 124 (1) ◽  
pp. 30
Author(s):  
Kevin G. Tolhurst
Keyword(s):  
Prescribed Fire ◽  
Fire Severity ◽  
Fire Effects ◽  
Royal Commission ◽  
Mixed Species ◽  
Terrestrial Mammals ◽  
Low Intensity ◽  
Eucalypt Forest ◽  
Fire Characteristics ◽  
Understorey Plants

The Wombat Fire Effects Study was established to address a number of questions in relation to the effects of repeated low-intensity fires in mixed species eucalypt forest in the foothills of Victoria. This study has now been going for 25 years and has included the study of understorey plants, fuels, bats, terrestrial mammals, reptiles, invertebrates, fungi, birds, soils, tree growth, fire behaviour and weather. This forest system has shown a high resilience to fire that is attributed here to the patchiness and variability in the fire characteristics within a fire and the relatively small proportion of the landscape being affected. A means of comparing the level of “injury” caused by low-intensity prescribed fire with high intensity wildfire is proposed so that the debate about leverage benefits (the reduction in wildfire area compared to the area of planned burning) can be more rational. There are some significant implications for assessing the relative environmental impacts of wildfire compared with the planned burning program being implemented in Victoria since the Victorian Bushfires Royal Commission recommendations (Teague et al. 2010).

scholarly journals Perceptions of Irrigation Water Management Practices in the Mississippi Delta

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 186
Author(s):  
Carson Roberts ◽  
Drew M. Gholson ◽  
Nicolas Quintana-Ashwell ◽  
Gurpreet Kaur ◽  
Gurbir Singh ◽  
...  
Keyword(s):  
Water Management ◽  
Mississippi River ◽  
Irrigation Water ◽  
Management Practices ◽  
Mississippi Delta ◽  
Water Saving ◽  
Irrigation Water Management ◽  
Highly Efficient ◽  
Irrigation Technology ◽  
Over Time

The Mississippi River Valley Alluvial Aquifer (MRVAA) is being depleted, and practices that improve water stewardship have been developed to reduce drawdown. This study assesses how Mississippi Delta producers changed their perceptions of these practices over time. The analysis employs data from two surveys carried-out in 2012 and 2014 of all Mississippi permittees who held an agricultural well permit drawing from the MRVAA. Focusing on water-saving practices, this study found that producer perception of the usability of flowmeters improved over time. About 80% and 90% more producers growing corn and soybeans, respectively, felt that computerized hole selection was highly efficient. In 2014, 38% of corn and 35% of soybean producers believed that shortened furrow length was a highly efficient practice—up from 21% in corn and 24% in soybean producers in 2012. Approval of irrigation automation, moisture probes, and other irrigation technology rose from 75%of producers in 2012 to 88% by 2014. Favorability toward water-saving practices increased overall between the survey years.

scholarly journals First Report of Pythium aphanidermatum Causing Stalk Rot on Abelmoschus manihot (L. ) Medic in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Qing Qu ◽  
Liu Shiwei ◽  
Ning Liu ◽  
Yunxia Liu ◽  
Jia Hui ◽  
...  
Keyword(s):  
Management Practices ◽  
Vascular System ◽  
Morphological Characteristics ◽  
Pythium Aphanidermatum ◽  
Negative Control ◽  
Perennial Herb ◽  
Universal Primers ◽  
First Report ◽  
Stalk Rot ◽  
Aerial Hyphae

Abelmoschus manihot (Linn. ) Medicus (A. manihot) is an annual to perennial herb of the Malvaceae okra, mainly distributed in Guangdong, Guangxi, Fujian, Hunan, Hubei provinces. It can not only be used as an ornamental flower, but also has important economic and medicinal value. Last year, 10% A. manihot in 1,000 acres were observed with stalk rot in the Zhongshang Agricultural Industrial Park, 50 meters east of Provincial Highway 235 in Gaoyang County of Hebei province. Internal discoloration of the stem began brown to black discoloration of the vascular system and became hollow, with the mycelium growing on the surface. Stems from symptomatic plants (approximately 5 mm2) were dissected, washed free of soil, then soaked in 75% ethanol for 16 s to surface-sterilize, and 40 s in HgCl2, then rinsed three times in sterile water. After being dried with blotting paper, five pieces were placed on potato dextrose agar (PDA). After cultured 2 or 3 days, five isolates were purified and re-cultured on PDA in the dark at 25°C. The color of the colony was white. The hyphae were radial in PDA, and the aerial hyphae were flocculent, well-developed with luxuriant branches. The colonies were white and floccus, and the aerial hyphae were well developed, branched and without septum on corn meal agar (CMA). The sporangia were large or petal shaped, composed of irregular hyphae, terminal or intermediate , with the size of (31.6-88.4) μm ×(12.7- 14.6) μm. Vesicles were spherical, terminal or intermediate, ranging from 14.6 to 18.5μm. Oogonia were globose, terminal and smooth which stipe was straight. Antheridia were clavate or baggy and mostly intercalary, sometimes terminal. Oospores were aplerotic, 21.5 to 30.0 μm in diameter, 1.6 to 3.1 μm in wall thickness. The isolates morphological characteristics were consistent with P. aphanidermatum (van der Plaats-Niterink 1981, Wu et al. 2021 ). To identify the isolates, universal primers ITS1/ITS4 (White et al. 1993) were used for polymerase chain reaction–based molecular identification. The amplification region was sequenced by Sangon Biotech (Shanghai, China) and submitted to GenBank (MW819983). BLAST analysis showed that the sequence was 100% identical to Pythium aphanidermatum. Pathogenicity tests were conducted 3 times, with 4 treatments and 2 controls each time. The plants treated were 6 months old. Then the hyphae growing on PDA for 7 days were cut into four pieces. Next, they were inoculated into the soil of the A. manihot. Negative control was inoculated only with PDA for 7 days ( Zhang et al. 2000). The plants were then placed in a greenhouse under 28°C, 90% relative humidity. After inoculated 20 to 30 days, the infected plants showed stalk rot, the same symptoms as observed on the original plants. The control plants didn’t display symptoms. Pythium aphanidermatum was re-isolated from infected stems and showed the same characteristics as described above and was identical in appearance to the isolates used to inoculate the plants. To our knowledge, this is the first report of Pythium aphanidermatum infecting A. manihot stem and causing stalk rot in China. It may become a significant problem for A. manihot. Preliminary management practices are needed for reducing the cost and losses of production.

Management Commitments that Maximize Business Impact from IT

2014 ◽  
Vol 29 (2) ◽  
pp. 114-127 ◽  
Author(s):  
Anne Quaadgras ◽  
Peter Weill ◽  
Jeanne W Ross
Keyword(s):  
Financial Performance ◽  
Case Studies ◽  
Value Creation ◽  
Management Practices ◽  
Publicly Traded ◽  
Business Impact ◽  
It Value ◽  
It Capabilities ◽  
Small Set ◽  
Over Time

As digitization becomes pervasive, many organizations struggle to drive value from the growing number of IT-related opportunities. We show how the drivers of IT value creation can be framed as firm-wide commitments to a set of IT capabilities. On the basis of 20 published case studies, we identify a small set of IT decisions that organizations must make to use IT to successfully enhance their impact. We group these decisions into a framework of four commitments. Making these commitments helps organizations reinforce what really matters over time, which in turn helps focus the attention of their employees. We demonstrate, via a survey of 210 publicly traded firms, that firms which are more effective in making these four commitments have higher business impact from IT, which in turn correlates with higher financial performance. We suggest the construct of commitment is a step toward unifying the IT value literature and creating an overarching concept that brings together many of the important management practices identified in previous work.

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