scholarly journals Distribution pattern of orchids in Uttarakhand, Western Himalayas, India

2012 ◽  
Vol 3 (1) ◽  
pp. 5 ◽  
Author(s):  
Jeewan Singh Jalal
Keyword(s):  
Western Ghats ◽  
Suitable Habitat ◽  
Western Himalayas ◽  
Tropical Zone ◽  
Orchid Species ◽  
Eastern Himalayas ◽  
Terrestrial Orchids ◽  
Growth Development ◽  
Low Altitude ◽  
The Tropics

Orchids are widely distributed in tropics, subtropics and temperate regions. Within the tropics, orchids form an important feature of the vegetation, chiefly as epiphytes. India’s epiphytic orchid is to be found primarily in the Eastern Himalayas and Western Ghats, while the terrestrial species flourishes in the Western Himalayas. In the state of Uttarakhand, India, orchid distribution is not homogeneous. Orchids are typically concentrated along the riverine areas and in pockets of moist forests where there is suitable habitat for their growth, development and regeneration. The purpose of this study was to provide a general review of the distribution of orchid species (epiphytic and terrestrial) in Uttarakhand. A total of 240 species (of which 10 are endemic) belonging to 73 <em>genera</em> were recorded. The largest number of orchid species (terrestrial and epiphytic) were encountered in the sub-tropical zone (&lt;1500 m). Terrestrial orchids were distributed throughout the altitudinal gradient, but the largest number of species occurred in two ecotones between high and low altitude forests (1500-2000 m and 3000-3500 m). Twenty-one species were restricted to a particular habitat.

scholarly journals The Impact of Human Pressure and Climate Change on the Habitat Availability and Protection of Cypripedium (Orchidaceae) in Northeast China

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 84
Author(s):  
Huanchu Liu ◽  
Hans Jacquemyn ◽  
Xingyuan He ◽  
Wei Chen ◽  
Yanqing Huang ◽  
...  
Keyword(s):  
Climate Change ◽  
Northeast China ◽  
Habitat Destruction ◽  
Changbai Mountains ◽  
Suitable Habitat ◽  
Human Pressure ◽  
Terrestrial Orchids ◽  
The Future ◽  
Suitable Habitats ◽  
The Impact

Human pressure on the environment and climate change are two important factors contributing to species decline and overall loss of biodiversity. Orchids may be particularly vulnerable to human-induced losses of habitat and the pervasive impact of global climate change. In this study, we simulated the extent of the suitable habitat of three species of the terrestrial orchid genus Cypripedium in northeast China and assessed the impact of human pressure and climate change on the future distribution of these species. Cypripedium represents a genus of long-lived terrestrial orchids that contains several species with great ornamental value. Severe habitat destruction and overcollection have led to major population declines in recent decades. Our results showed that at present the most suitable habitats of the three species can be found in Da Xing’an Ling, Xiao Xing’an Ling and in the Changbai Mountains. Human activity was predicted to have the largest impact on species distributions in the Changbai Mountains. In addition, climate change was predicted to lead to a shift in distribution towards higher elevations and to an increased fragmentation of suitable habitats of the three investigated Cypripedium species in the study area. These results will be valuable for decision makers to identify areas that are likely to maintain viable Cypripedium populations in the future and to develop conservation strategies to protect the remaining populations of these enigmatic orchid species.

scholarly journals Distribution and habitat associations of the Critically Endangered frog Walkerana phrynoderma (Anura: Ranixalidae), with an assessment of potential threats, abundance, and morphology

2018 ◽  
Vol 17 (1) ◽  
pp. 21
Author(s):  
Arun Kanagavel ◽  
Sethu Parvathy ◽  
Abhiijth P. Chundakatil ◽  
Neelesh Dahanukar ◽  
Benjamin Tapley
Keyword(s):  
Western Ghats ◽  
Tamil Nadu ◽  
Habitat Associations ◽  
Critically Endangered ◽  
Suitable Habitat ◽  
Time Activity ◽  
Western Ghats Of India ◽  
Pesticide Runoff ◽  
The Impact ◽  
The Western Ghats

Distribution and habitat associations of the Critically Endangered frog Walkerana phrynoderma (Anura: Ranixalidae), with an assessment of potential threats, abundance, and morphology. Little is known about Walkerana phrynoderma, a frog endemic to the Anamalai Hills of the Western Ghats of India. Baseline information (i.e., distribution, threats, habitat characteristics, activity patterns, and relative abundance) is provided for this species, with the aim of improving our understanding of the status of the species in the wild. Visual-encounter, transect, and time-activity budget surveys were conducted in and around the Anamalai Hills of the Western Ghats. The frog skin was swabbed to determine the presence/absence of Batrachochytrium dendrobatidis, and habitat and environmental characteristics were recorded at sites where W. phrynoderma was found. These data were compared with those of sites apparently lacking this species that had suitable habitat. Walkerana phrynoderma is restricted to evergreen forests between 1300 and 1700 m a.s.l. in the Anamalai Tiger Reserve and at Munnar; thus, its range was extended from the state of Tamil Nadu to the adjoining state of Kerala. Pesticide runoff and human disturbance are the most severe threats to the species; B. dendrobatidis was not detected. This nocturnal anuran prefers forest edges and is associated with well-shaded forest foors in cool areas near freshwater streams. Walkerana phrynoderma is rarely encountered whereas its congener, W. leptodactyla, is more common. The impact of anthropogenic disturbances, especially waste disposal and development of tourism infrastructure, should be evaluated. The land that is owned by the Forest Department peripheral to the protected areas could be designated as eco-sensitive sites to prevent changes in land use that could have an adverse effect on W. phrynoderma.

scholarly journals Effects of shading on the growth, development and yield of winged bean (Psophocarpus tetragonolobus)

2020 ◽  
Vol 50 (2) ◽  
Author(s):  
Murthazar Naim Raai ◽  
Nurul Amalina Mohd Zain ◽  
Normaniza Osman ◽  
Nur Ardiyana Rejab ◽  
Nurul Amylia Sahruzaini ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Physiological Responses ◽  
Canopy Cover ◽  
Winged Bean ◽  
Psophocarpus Tetragonolobus ◽  
Photosynthetic Gas Exchange ◽  
Growth Development ◽  
The Tropics ◽  
Protein Rich

ABSTRACT: An experiment was conducted to investigate the effects of different shading regimes [i.e., 60% (heavy), 30% (moderate), and 0% (control)] on 25 traits associated with the morphological features, photosynthetic gas exchange and agronomic characteristics of winged bean (Psophocarpus tetragonolobus), an underutilized protein-rich legume from the tropics. Collectively, 80% of the studied variables displayed significant differences (P<0.05) between at least two shade treatments. Shading generally showed most pronounced effect on the physiological traits of the legume, whereby the stomatal conductance, photosynthetic and transpiration rate differed significantly among plants for all treatments. The non-shaded plants were observed to have superior growth and physiological responses than the shaded plants. Interestingly, the moderately shaded plants exhibited the highest yield per plant, which significantly differed from the non-shaded and heavily shaded plants. This indicated that winged bean can adapt to partial canopy cover, making it a potential nitrogen-fixing cash crop which can be planted together with fruit or oil trees in commercial plantations.

Impatiens ramasubbuana, a new name for Impatiens palniensis Ramasubbu (Balsaminaceae)

Phytotaxa ◽  
2021 ◽  
Vol 500 (1) ◽  
pp. 52-54
Author(s):  
RAMALINGAM KOTTAIMUTHU ◽  
PERUMAL MURUGAN ◽  
JOHN KENNEDY JOHN PRAVEEN KUMAR ◽  
MUTHURAMALINGAM JOTHI BASU
Keyword(s):  
Western Ghats ◽  
Tamil Nadu ◽  
Eastern Himalayas ◽  
New Name ◽  
Recent Estimate ◽  
The Western Ghats

The genus Impatiens Linnaeus (1753: 937) contains a wealth of untapped treasures for gardeners and it is one of the mega diverse genera of angiosperms comprise about 1059 species (POWO 2020). According to the recent estimate, India is known to have 250 species and majority of them occur in Eastern Himalayas (Gogoi et al. 2018) and the Western Ghats (Bhaskar 2012). Tamil Nadu is one of the plant-rich states in the country and with 5674 angiosperm taxa, it ranks first among all the states in the country (Lakshminarasimhan et al. 2014).

scholarly journals Climatic shifts drove major contractions in avian latitudinal distributions throughout the Cenozoic

2019 ◽  
Vol 116 (26) ◽  
pp. 12895-12900 ◽  
Author(s):  
Erin E. Saupe ◽  
Alexander Farnsworth ◽  
Daniel J. Lunt ◽  
Navjit Sagoo ◽  
Karen V. Pham ◽  
...  
Keyword(s):  
Ecological Niche Modeling ◽  
Suitable Habitat ◽  
Coarse Scale ◽  
Climate Variable ◽  
Biogeographic History ◽  
Stem Lineage ◽  
History Of ◽  
Geographic Distributions ◽  
The Tropics ◽  
Early Cenozoic

Many higher level avian clades are restricted to Earth’s lower latitudes, leading to historical biogeographic reconstructions favoring a Gondwanan origin of crown birds and numerous deep subclades. However, several such “tropical-restricted” clades (TRCs) are represented by stem-lineage fossils well outside the ranges of their closest living relatives, often on northern continents. To assess the drivers of these geographic disjunctions, we combined ecological niche modeling, paleoclimate models, and the early Cenozoic fossil record to examine the influence of climatic change on avian geographic distributions over the last ∼56 million years. By modeling the distribution of suitable habitable area through time, we illustrate that most Paleogene fossil-bearing localities would have been suitable for occupancy by extant TRC representatives when their stem-lineage fossils were deposited. Potentially suitable habitat for these TRCs is inferred to have become progressively restricted toward the tropics throughout the Cenozoic, culminating in relatively narrow circumtropical distributions in the present day. Our results are consistent with coarse-scale niche conservatism at the clade level and support a scenario whereby climate change over geological timescales has largely dictated the geographic distributions of many major avian clades. The distinctive modern bias toward high avian diversity at tropical latitudes for most hierarchical taxonomic levels may therefore represent a relatively recent phenomenon, overprinting a complex biogeographic history of dramatic geographic range shifts driven by Earth’s changing climate, variable persistence, and intercontinental dispersal. Earth’s current climatic trajectory portends a return to a megathermal state, which may dramatically influence the geographic distributions of many range-restricted extant clades.

scholarly journals Hazard from Himalayan glacier lake outburst floods

2019 ◽  
Vol 117 (2) ◽  
pp. 907-912 ◽  
Author(s):  
Georg Veh ◽  
Oliver Korup ◽  
Ariane Walz
Keyword(s):  
Western Himalayas ◽  
Return Periods ◽  
Outburst Flood ◽  
Average Volume ◽  
Eastern Himalayas ◽  
Outburst Floods ◽  
Hindu Kush ◽  
Order Of Magnitude ◽  
Highest Density Interval ◽  
Increasing Trends

Sustained glacier melt in the Himalayas has gradually spawned more than 5,000 glacier lakes that are dammed by potentially unstable moraines. When such dams break, glacier lake outburst floods (GLOFs) can cause catastrophic societal and geomorphic impacts. We present a robust probabilistic estimate of average GLOFs return periods in the Himalayan region, drawing on 5.4 billion simulations. We find that the 100-y outburst flood has an average volume of 33.5+3.7/−3.7 × 106 m3 (posterior mean and 95% highest density interval [HDI]) with a peak discharge of 15,600+2,000/−1,800 m3⋅s−1. Our estimated GLOF hazard is tied to the rate of historic lake outbursts and the number of present lakes, which both are highest in the Eastern Himalayas. There, the estimated 100-y GLOF discharge (∼14,500 m3⋅s−1) is more than 3 times that of the adjacent Nyainqentanglha Mountains, and at least an order of magnitude higher than in the Hindu Kush, Karakoram, and Western Himalayas. The GLOF hazard may increase in these regions that currently have large glaciers, but few lakes, if future projected ice loss generates more unstable moraine-dammed lakes than we recognize today. Flood peaks from GLOFs mostly attenuate within Himalayan headwaters, but can rival monsoon-fed discharges in major rivers hundreds to thousands of kilometers downstream. Projections of future hazard from meteorological floods need to account for the extreme runoffs during lake outbursts, given the increasing trends in population, infrastructure, and hydropower projects in Himalayan headwaters.

scholarly journals Asymbiotic in vitro germination and seed quality assessment of Australian terrestrial orchids

2012 ◽  
Vol 60 (7) ◽  
pp. 592 ◽  
Author(s):  
Nicole Dowling ◽  
Manfred Jusaitis
Keyword(s):  
Seed Quality ◽  
Culture Media ◽  
Vital Staining ◽  
Terrestrial Orchid ◽  
Triphenyltetrazolium Chloride ◽  
Asymbiotic Seed Germination ◽  
Orchid Species ◽  
Terrestrial Orchids ◽  
Asymbiotic Germination

Determining the seed quality and germination requirements for threatened orchid species in storage is vital for future conservation efforts. Seeds of many Australian terrestrial orchid species are held in conservation collections around the country, but few have been germinated in vitro, fuelling concerns over their long-term viability. This study tested three methods of assessing orchid seed quality; asymbiotic germination was compared with vital staining using triphenyltetrazolium chloride or fluorescein diacetate. Six culture media were examined for efficacy in promoting asymbiotic seed germination of four Australian terrestrial orchid species (Pterostylis nutans, Microtis arenaria, Thelymitra pauciflora and Prasophyllum pruinosum). Germination occurred on all media but germination rates were consistently highest on BM1 and development was most advanced on BM1, P723 and Malmgren media. Subsequent trials tested the efficacy of BM1 for asymbiotic germination of additional genera (Caladenia, Calochilus and Diuris), several congeneric species, and two species collected from several different provenances within each of their ranges. The results indicate that asymbiotic germination on BM1 medium is an effective technique for testing the performance of Australian terrestrial orchid seeds. The efficacy of vital stains to determine seed viability, however, remains uncertain, as significant disagreement between degree of staining and germinability was observed for some species.

Sign in / Sign up

Export Citation Format

Share Document