scholarly journals Frequency, Diversity and Ecological Strategies of Epiphytic Lichens in the Swiss Central Plateau and the Pre-Alps

1997 ◽  
Vol 29 (03) ◽  
pp. 237 ◽  
Author(s):  
Michael Dietrich ◽  
Christoph Scheidegger
Keyword(s):  
Epiphytic Lichens ◽  
Frequency Diversity ◽  
Ecological Strategies ◽  
Central Plateau

scholarly journals Frequency, Diversity and Ecological Strategies of Epiphytic Lichens in the Swiss Central Plateau and the Pre-Alps

1997 ◽  
Vol 29 (3) ◽  
pp. 237-258 ◽  
Author(s):  
Michael Dietrich ◽  
Christoph Scheidegger
Keyword(s):  
Species Richness ◽  
Ecological Factors ◽  
Epiphytic Lichens ◽  
Frequency Diversity ◽  
Central Plateau ◽  
Lichen Diversity ◽  
Β Diversity ◽  
Α Diversity ◽  
Elevational Range ◽  
Vegetation Formation

AbstractTo identify representative quantitative criteria for the creation of a future Red List of epiphytic lichens, 849 trees in 132 long-term ecological observation plots in the Swiss Central Plateau and the Pre-Alps were surveyed by standard sampling. Based on the trees, frequency data of the lichen taxa observed are described by the log series model, indicating the controlling effect of few ecological factors. Based on the plots, four classes of scarcity, each comprising 25% of the species, were established. As a contribution to the development of a national, representative survey of lichens, α-diversity (species richness, species density) and β-diversity (dissimilarity) were calculated in terms of region, vegetation formation, vegetation belt and for their combinations. Differences in lichen diversity between the Central Plateau and the Pre-Alps were caused by the bigger elevational range in the Pre-Alps, which resulted in a higher species richness. α-Diversity of forest and non-forest were similar, whereas each vegetation formation showed one third of its species restricted to it. The contributions to the total lichen diversity of crustose, foliose and fruticose as well as of generative and vegetative species was calculated. Specific features along the altitudinal gradient of vegetation belts emerged: the percentage of crustose and generative lichens declined with every altitudinal step, increased in fruticose and vegetative lichens, and was the same in foliose species.

Improving Space-Time-Frequency MIMO-OFDM with ICI Self-Cancellation Scheme using Least Square Error Estimator

2015 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
Nur Farahiah Ibrahim ◽  
Zahari Abu Bakar ◽  
Azlina Idris
Keyword(s):  
Channel Estimation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Symbol Error Rate ◽  
Space Time ◽  
Least Square ◽  
Error Estimator ◽  
Frequency Diversity ◽  
Time Frequency ◽  
Mimo Ofdm ◽  
Subcarrier Mapping

Channel estimation techniques for Multiple-input Multiple-output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) based on comb type pilot arrangement with least-square error (LSE) estimator was investigated with space-time-frequency (STF) diversity implementation. The frequency offset in OFDM effected its performance. This was mitigated with the implementation of the presented inter-carrier interference self-cancellation (ICI-SC) techniques and different space-time subcarrier mapping. STF block coding in the system exploits the spatial, temporal and frequency diversity to improve performance. Estimated channel was fed into a decoder which combined the STF decoding together with the estimated channel coefficients using LSE estimator for equalization. The performance of the system was compared by measuring the symbol error rate with a PSK-16 and PSK-32. The results show that subcarrier mapping together with ICI-SC were able to increase the system performance. Introduction of channel estimation was also able to estimate the channel coefficient at only 5dB difference with a perfectly known channel.

Stufige Mischwälder im Unter-Thurgau | Stratified Mixed Forests in the Lower Thurgau

1999 ◽  
Vol 150 (7) ◽  
pp. 249-251
Author(s):  
Heinz Kuhn
Keyword(s):  
20Th Century ◽  
Forest Regeneration ◽  
Central Plateau ◽  
Intervention Intensity ◽  
Continuous Forest ◽  
Federal Institute ◽  
As Species ◽  
Landscape Research ◽  
Selection Forest ◽  
Structure Diversity

As in many parts of the Swiss Central Plateau, vast coppices with standards have grown in the region of Diessenhofen for centuries. While in other parts of the first decades of the 20th century the forests were converted to areas of forest regeneration species, the foresters of the Diessenhofen region altered numerous pillaged coppices with standards to a stratified continuous forest. The advantages of this form of management such as species and structure diversity and lower costs in comparison with the forest stratified by age are being presented. Each of the four foresters in the region has formed different stand images through his personal intervention intensity. There are different ways possible for achieving a continuous forest, in order to prove this, differences of managing a selection forest system are carried out by the four regional foresters. After decades of experience in tending stands established out of former coppices with standards, the approach of converting plenter forests from existing forests stratified by age to stratified continuous forests is experienced. The successes also encouraged the foresters of the neighbouring district Steckborn to do the same. This creative task is being accompanied scientifically by the WSL (Federal Institute of Forest, Snow and Landscape Research, Birmensdorf, Switzerland), which has established permanent observation areas. The steps in the previously intuitive procedure can, therefore, now be traced.

DELINEATING THERMAL MINERAL DEPOSITS ON THE CENTRAL PLATEAU IN YELLOWSTONE N.P., WY

2018 ◽  
Author(s):  
Megan M. Aunan ◽  
◽  
Jerry P. Fairley ◽  
Peter B. Larson ◽  
Haylin Moser
Keyword(s):  
Mineral Deposits ◽  
Central Plateau

scholarly journals Integrating dark diversity and functional traits to enhance nature conservation of epiphytic lichens: a case study from Northern Italy

2021 ◽  
Author(s):  
Diego Pires Ferraz Trindade ◽  
Meelis Pärtel ◽  
Carlos Pérez Carmona ◽  
Tiina Randlane ◽  
Juri Nascimbene
Keyword(s):  
Climate Change ◽  
Nature Conservation ◽  
Functional Traits ◽  
Growth Form ◽  
Northern Italy ◽  
Epiphytic Lichens ◽  
Mountain Areas ◽  
High Elevations ◽  
Harsh Conditions

AbstractMountains provide a timely opportunity to examine the potential effects of climate change on biodiversity. However, nature conservation in mountain areas have mostly focused on the observed part of biodiversity, not revealing the suitable but absent species—dark diversity. Dark diversity allows calculating the community completeness, indicating whether sites should be restored (low completeness) or conserved (high completeness). Functional traits can be added, showing what groups should be focused on. Here we assessed changes in taxonomic and functional observed and dark diversity of epiphytic lichens along elevational transects in Northern Italy spruce forests. Eight transects (900–1900 m) were selected, resulting in 48 plots and 240 trees, in which lichens were sampled using four quadrats per tree (10 × 50 cm). Dark diversity was estimated based on species co-occurrence (Beals index). We considered functional traits related to growth form, photobiont type and reproductive strategy. Linear and Dirichlet regressions were used to examine changes in taxonomic metrics and functional traits along gradient. Our results showed that all taxonomic metrics increased with elevation and functional traits of lichens differed between observed and dark diversity. At low elevations, due to low completeness and harsh conditions, both restoration and conservation activities are needed, focusing on crustose species. Towards high elevations, conservation is more important to prevent species pool losses, focusing on macrolichens, lichens with Trentepohlia and sexual reproduction. Finally, dark diversity and functional traits provide a novel tool to enhance nature conservation, indicating particular threatened groups, creating windows of opportunities to protect species from both local and regional extinctions.

scholarly journals Constraints to Pearl Millet (Pennisetum glaucum) Production and Farmers’ Approaches to Striga hermonthica Management in Burkina Faso

2021 ◽  
Vol 13 (15) ◽  
pp. 8460
Author(s):  
Armel Rouamba ◽  
Hussein Shimelis ◽  
Inoussa Drabo ◽  
Mark Laing ◽  
Prakash Gangashetty ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Pearl Millet ◽  
Management Practices ◽  
Pennisetum Glaucum ◽  
Control Measures ◽  
Striga Hermonthica ◽  
Soil Conditions ◽  
Management Options ◽  
Central Plateau ◽  
South Central

Pearl millet (Pennisetum glaucum) is a staple food crop in Burkina Faso that is widely grown in the Sahelian and Sudano-Sahelian zones, characterised by poor soil conditions and erratic rainfall, and high temperatures. The objective of this study was to document farmers’ perceptions of the prevailing constraints affecting pearl millet production and related approaches to manage the parasitic weeds S. hermonthica. The study was conducted in the Sahel, Sudano-Sahelian zones in the North, North Central, West Central, Central Plateau, and South Central of Burkina Faso. Data were collected through a structured questionnaire and focus group discussions involving 492 participant farmers. Recurrent drought, S. hermonthica infestation, shortage of labour, lack of fertilisers, lack of cash, and the use of low-yielding varieties were the main challenges hindering pearl millet production in the study areas. The majority of the respondents (40%) ranked S. hermonthica infestation as the primary constraint affecting pearl millet production. Respondent farmers reported yield losses of up to 80% due to S. hermonthica infestation. 61.4% of the respondents in the study areas had achieved a mean pearl millet yields of <1 t/ha. Poor access and the high cost of introduced seed, and a lack of farmers preferred traits in the existing introduced pearl millet varieties were the main reasons for their low adoption, as reported by 32% of respondents. S. hermonthica management options in pearl millet production fields included moisture conservation using terraces, manual hoeing, hand weeding, use of microplots locally referred to as ‘zaï’, crop rotation and mulching. These management techniques were ineffective because they do not suppress the below ground S. hermonthica seed, and they are difficult to implement. Integrated management practices employing breeding for S. hermonthica resistant varieties with the aforementioned control measures could offer a sustainable solution for S. hermonthica management and improved pearl millet productivity in Burkina Faso.

scholarly journals Demographic Effects of Severe Fire in Montane Shrubland on Tasmania’s Central Plateau

Fire ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 32
Author(s):  
Judy A. Foulkes ◽  
Lynda D. Prior ◽  
Steven W. J. Leonard ◽  
David M. J. S. Bowman
Keyword(s):  
Woody Species ◽  
Fire Frequency ◽  
Fire Season ◽  
Burned Area ◽  
Large Area ◽  
Seedling Regeneration ◽  
Central Plateau ◽  
Conservation Area ◽  
Severe Fire ◽  
Representative Area

Australian montane sclerophyll shrubland vegetation is widely considered to be resilient to infrequent severe fire, but this may not be the case in Tasmania. Here, we report on the vegetative and seedling regeneration response of a Tasmanian non-coniferous woody montane shrubland following a severe fire, which burned much of the Great Pine Tier in the Central Plateau Conservation Area during the 2018–2019 fire season when a historically anomalously large area was burned in central Tasmania. Our field survey of a representative area burned by severe crown fire revealed that more than 99% of the shrubland plants were top-killed, with only 5% of the burnt plants resprouting one year following the fire. Such a low resprouting rate means the resilience of the shrubland depends on seedling regeneration from aerial and soil seedbanks or colonization from plants outside the burned area. Woody species’ seedling densities were variable but generally low (25 m−2). The low number of resprouters, and reliance on seedlings for recovery, suggest the shrubland may not be as resilient to fire as mainland Australian montane shrubland, particularly given a warming climate and likely increase in fire frequency.

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