scholarly journals Moth versus fly: a preliminary study of the pollination mode of two species of endemic Asteraceae from St Helena (Commidendrum robustum and C. rugosum) and its conservation implications

2020 ◽  
Vol 8 ◽  
Author(s):  
Mikko Paajanen ◽  
Quentin Cronk
Keyword(s):  
Limiting Factor ◽  
Forest Site ◽  
Isolated Populations ◽  
Conservation Implications ◽  
Species Survival ◽  
Insect Visitation ◽  
Preliminary Study ◽  
Pollination Mode ◽  
St Helena ◽  
Atlantic Island

Commidendrum robustum (Roxb.) DC. (St Helena gumwood) and C. rugosum (Dryand.) DC. (St Helena scrubwood) are ecologically important, endemic woody Asteraceae from the isolated South Atlantic island of St Helena. Once very abundant, they now exist in sparse fragmented populations due to 500 years of environmental destruction. They are sister taxa that evolved on the island and are reported to hybridise. Commidendrum rugosum has a saucer-like erect capitulum, whereas C. robustum has a somewhat globular hanging capitulum. Using daytime timelapse photography to follow capitula through their life cycle, we found that C. rugosum appears to be myophilous, visited largely by flies (including the endemic syrphid, Sphaerophoria beattiei Doesburg & Doesburg) and occasionally by Lepidoptera. Commidendrum robustum, on the other hand, although visited by flies, strongly attracts moths (especially noted at the Millennium Forest site). Our data suggest that moth visits may reduce visits from flies due to the sensitivity of flies to interference by other insects. We conclude that C. robustum may have a mixed syndrome of myophily/phalaenophily and that there is apparently some divergence of the pollination niche between the two species. Its potential in attracting moths, coupled with its former abundance, suggests that it may have been a major food source for adults of the numerous endemic moths. Pollinator activity was measured by insect visitation rates (mean visits per capitulum per day, V) and insect residence time (mean pollinator kiloseconds per capitulum per day, R). Both are higher for C. robustum (C. rugosum, V = 16.4, R = 3.101; C. robustum, V = 34.0, R = 8.274), reflecting the abundance of moths on the capitula at the Millennium Forest site. The conservation implications of the pollination mode are that: (1) there is considerable pollinator activity on the capitula and pollination is not currently a limiting factor for plant reproduction; (2) gene exchange between geographically-isolated populations of C. rugosum is likely to be minimal due to the apparent reliance of the species for pollination on small flies (especially Sphaerophoria beattiei), which are believed to be not effective as pollinators over long distances (> 1 km). A possible exception is the strong-flying drone-fly, Eristalis tenax Linn. which, although not as abundant as Sphaerophoria, does visit the flowers; (3) there is considerable overlap between the two species in flower visitors and interspecific pollen transfer is possible where the two species grow intermixed (which has potential positive and negative implications for species survival).

scholarly journals Dramatic decline of François' langur Trachypithecus francoisi in Guangxi Province, China

Oryx ◽  
2007 ◽  
Vol 41 (1) ◽  
pp. 38-43 ◽  
Author(s):  
Youbang Li ◽  
Chengming Huang ◽  
Ping Ding ◽  
Zheng Tang ◽  
Chris Wood
Keyword(s):  
Population Size ◽  
Conservation Status ◽  
Guangxi Province ◽  
Isolated Populations ◽  
Term Survival ◽  
Management Planning ◽  
Management Measures ◽  
Species Survival ◽  
Dramatic Decline ◽  
Trachypithecus Francoisi

Interviews with local people and a survey were carried out in 23 counties of south-west Guangxi Province from April 2002 to June 2003 to evaluate the conservation status of François' langur Trachypithecus francoisi and assess the extent and nature of threats to the species' survival. François' langurs were found in only 10 counties compared with their presence in 23 counties before 1990. The total population size is estimated to be 307 individuals in 14 isolated populations. This represents a 90% decrease in population size since the early 1980s and an 85% decrease since the mid 1990s. The primary threat to the langur is hunting, mainly for traditional medicine. Our results suggest that conservation efforts for the species have been ineffectual during the last decade and, even within reserves, few direct management measures seem to have been taken to protect and conserve the langurs. Without the instigation of such measures it seems likely that François' langur will disappear both inside and outside reserves. To ensure the long-term survival of Francois' langur in Guangxi Province increased investment and improved management, planning, and training of reserve managers and staff is required, with a particular focus on the key remaining reserves and sites for the langur. Some of this work is now underway.

Deep phylogenetic structure has conservation implications for ornate rainbowfish (Melanotaeniidae:Rhadinocentrus ornatus) in Queensland, eastern Australia

2004 ◽  
Vol 55 (2) ◽  
pp. 165 ◽  
Author(s):  
Timothy J. Page ◽  
Suman Sharma ◽  
Jane M. Hughes
Keyword(s):  
Large Scale ◽  
Mitochondrial Atpase ◽  
Isolated Populations ◽  
Exotic Fish ◽  
Phylogenetic Structure ◽  
Bay Area ◽  
Conservation Implications ◽  
South Wales ◽  
Eastern Australia ◽  
Atpase Gene

The freshwater fish, Rhadinocentrus ornatus Regan, 1914, has a patchy distribution through coastal drainages of Queensland and New South Wales, eastern Australia. Isolated populations of R. ornatus are found on several islands, as well as in a disjunct northern population 350 km from its nearest conspecific population. Deoxyribonucleic acid was extracted and sequenced for the mitochondrial ATPase gene to describe the geographic and genetic subdivision within the species. Four major clades were identified. These clades diverged between two and seven million years ago and so represent long-term divisions and possible units of conservation. There are conservation implications in that the narrow and localised distribution of R. ornatus overlaps with an area of large-scale land clearing, high human population and threats from introduced exotic fish. A particularly high centre of Rhadinocentrus diversity in the Tin Can Bay area of Queensland presents some interesting questions about the evolution of the genus Rhadinocentrus.

scholarly journals A Preliminary Study of the Effect of Bioavailable Fe and Co on the Anaerobic Digestion of Rice Straw

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 577 ◽  
Author(s):  
Gabriele Mancini ◽  
Stefano Papirio ◽  
Piet Lens ◽  
Giovanni Esposito
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Rice Straw ◽  
Microbial Growth ◽  
Volatile Fatty Acids ◽  
Limiting Factor ◽  
Bioavailable Fraction ◽  
Essential Trace Elements ◽  
Biomethane Production ◽  
Preliminary Study

Rice straw is an abundant and sustainable substrate for anaerobic digestion (AD), but it is often deficient in essential trace elements (TEs) for proper microbial growth and metabolism. A lack of TEs leads to AD imbalances and suboptimal biogas yields. However, the total TE concentration is not a sufficient indicator of the amount of TEs available to the microorganisms. Therefore, this study investigated the degree of bioavailability of iron (Fe) and cobalt (Co) during the AD of rice straw, and correlated it to the biomethane yields and volatile fatty acids (VFAs) produced. When the two TEs were dosed at 205 µg Fe/g TS and 18 µg Co/g TS of rice straw, the biomethane production was approximately 260 mL CH4/g VS, i.e., similar to that obtained when Fe and Co were not added. Despite an increased bioavailable fraction of 23 and 48% for Fe and Co, respectively, after TEs addition, the AD performance was not enhanced. Moreover, VFAs did not exceed 250 mg HAc/L both in the presence and absence of added TEs, confirming no enhancement of the methanogenesis step. Therefore, the bioavailability of Fe and Co was not a limiting factor for the biomethane production at low total VFAs concentration.

scholarly journals Recent decline of the St Helena Wirebird Charadrius sanctaehelenae

2009 ◽  
Vol 19 (1) ◽  
pp. 33-48 ◽  
Author(s):  
NEIL McCULLOCH
Keyword(s):  
Human Activity ◽  
Bird Species ◽  
South Atlantic ◽  
Critically Endangered ◽  
The South ◽  
Related Development ◽  
The Future ◽  
Vegetation Surveys ◽  
St Helena ◽  
Atlantic Island

SummaryThe Wirebird Charadrius sanctaehelenae, a plover, is the only surviving bird species endemic to the South Atlantic Island of St Helena. The species is currently dependent on habitats that are wholly anthropogenic or extensively modified by human activity. A census carried out during 2005–2006 showed that the Wirebird has undergone a decline of more than 40% over a five-year period to a total of 235 individuals. The species now qualifies for re-classification as ‘Critically Endangered’. Vegetation surveys support the results of a previous study in suggesting that the decline may be associated with degradation of the Wirebird's favoured grassland habitat due to reduction of livestock numbers. Predation by introduced mammals and birds is also likely to be a factor but this remains unquantified. The Wirebird may face additional threats to its habitat in the future unless potential tourism-related development associated with the proposed construction of an airport on the island is closely regulated.

scholarly journals Conservation implications of the drinking habits of Black-cheeked Lovebirds Agapornis nigrigenis in Zambia

2005 ◽  
Vol 15 (4) ◽  
pp. 383-396 ◽  
Author(s):  
LOUISE S. WARBURTON ◽  
MICHAEL R. PERRIN
Keyword(s):  
Natural Habitat ◽  
External Disturbance ◽  
Early Morning ◽  
Annual Rainfall ◽  
Limiting Factor ◽  
Drinking Behaviour ◽  
Water Supplies ◽  
Drinking Habits ◽  
Conservation Implications ◽  
Artificial Water

Since 1950, the annual rainfall in the habitat of Black-cheeked Lovebirds Agapornis nigrigenis has decreased, increasing dependence on artificial water supplies. In this study, the seasonal water requirements and drinking behaviour of the lovebirds in their natural habitat were investigated. During the dry season, lovebirds drank at the same water-point in the early morning and late afternoon. Flock sizes of birds at drinking sites ranged from 1 to 175 individuals. Birds from one locale all drank at the same waterhole. Black-cheeked Lovebirds were vigilant and highly cautious drinkers that did not drink at waterholes when disturbed by humans or livestock. The implications for conservation of the species are discussed. Since water availability is a limiting factor for the Black-cheeked Lovebird, gradual desiccation of its habitat has caused the reduction of its small distributional range. Because of increasing dependence on artificial water supplies in a highly localized distribution the priority for conservation management of the species must be creating and maintaining water resources with minimal external disturbance.

Conservation Implications of Drastic Reductions in the Smallest and Most Isolated Populations of Giant Pandas

2010 ◽  
Vol 24 (5) ◽  
pp. 1299-1306 ◽  
Author(s):  
LIFENG ZHU ◽  
XIANGJIANG ZHAN ◽  
HUA WU ◽  
SHANNING ZHANG ◽  
TAO MENG ◽  
...  
Keyword(s):  
Isolated Populations ◽  
Giant Pandas ◽  
Conservation Implications

Macrophthalmothrips argus (Karny) (Thysanoptera: Phlaeothripidae): a fungus-feeding thrips newly established on the Atlantic island of St Helena

2018 ◽  
Vol 154 (4) ◽  
pp. 303-307
Author(s):  
Dominique W. Collins
Keyword(s):  
South Africa ◽  
Endemic Species ◽  
Invasive Plant ◽  
Biocontrol Agent ◽  
Current Status ◽  
Ulex Europaeus ◽  
Thrips Species ◽  
St Helena ◽  
Atlantic Island ◽  
Specific Identity

Macrophthalmothrips argus (Karny) is here recorded as newly established on the island of St Helena in the South Atlantic Ocean. A review of the Thysanoptera fauna of St Helena is also presented. Macrophthalmothrips argus is the twelfth thrips species to be recorded from the island: the eleventh, Sericothrips staphylinus Haliday, was introduced onto the island as a biocontrol agent for the invasive plant Ulex europaeus in 1995, but its current status on the island is uncertain. A species of Aeolothrips present on the island has long been attributed to A. fasciatus (L.), but its specific identity has never been confirmed. Helenothrips tinctus zur Strassen, once regarded as a St Helena endemic species, is indicated to be itself an introduction, from South Africa.

scholarly journals Effects of forest characteristics on the abundance of alectorioid lichens in northern Finland

2006 ◽  
Vol 36 (11) ◽  
pp. 2955-2965 ◽  
Author(s):  
Lotta Maaria Jaakkola ◽  
Timo Päiviö Helle ◽  
Jussi Soppela ◽  
Markku Tapio Kuitunen ◽  
Mikko Juhani Yrjönen
Keyword(s):  
Norway Spruce ◽  
National Parks ◽  
Rangifer Tarandus ◽  
Dry Mass ◽  
Limiting Factor ◽  
Forest Site ◽  
Scotch Pine ◽  
Tree Species Composition ◽  
Important Indicator ◽  
Northern Forests

Quantitative knowledge of the abundance of epiphytic alectorioid lichens (Bryoria spp., Alectoria spp., and Usnea spp.) is important when evaluating the carrying capacity of the winter pastures of semidomesticated reindeer (Rangifer tarandus tarandus (L., 1758)) and woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)). This study, including a total of 234 sample plots, presents data on the biomass of alectorioid lichens in mature forests for the most common forest site types in the national parks of Oulanka, Pallas-Ounastunturi, and Lemmenjoki in northern Finland and relates them to forest stand characteristics. The biomass of alectorioid lichens on trees was estimated using the clump method in which the existing clumps of lichen thalli on branches are compared with clumps of lichens of known dry mass. Estimated biomasses were corrected by equations describing the ratio of estimated to measured biomass. We found the highest mean lichen biomasses (120 kg·ha–1) in subdry, Scotch pine (Pinus sylvestris L.) dominated sites above the timberline of Norway spruce (Picea abies (L.) Karst.). Below that timberline, the highest lichen biomasses were found in fresh (productive) sites dominated by Norway spruce. There the site-specific differences were mainly associated with tree species composition. Though in many previous studies forest age has been an important indicator of total lichen biomass, in our study areas lichen abundance was most commonly correlated with total volume of forest stands. The correlation of biomass with forest volume suggests that substrate availability was the most important limiting factor for alectorioid lichens in our study area. However, it is premature to say whether that is a common feature in northern forests over larger geographic areas.

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