scholarly journals Plant density and life history traits of Aconitum spicatum in North-central Nepal: effects of elevation and anthropogenic disturbances

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7574
Author(s):  
Deep J. Chapagain ◽  
Henrik Meilby ◽  
Suresh K. Ghimire
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Plant Density ◽  
Elevation Gradient ◽  
Seed Mass ◽  
Anthropogenic Disturbances ◽  
Life Stages ◽  
Conservation Area ◽  
North Central ◽  
Central Nepal

Increasing cross-border trade of medicinal and aromatic plants (MAPs) has put heavy pressure on a considerable number of species in the Himalayas. One of the threatened species in Nepal is Aconitum spicatum. Unfortunately for this species and for many others, our knowledge on population ecology and performance across the distribution range is insufficient, hindering the formulation of species-specific management plans. We therefore studied density and population structure of A. spicatum and assessed variation in its life history traits among three populations (subalpine, lower alpine and alpine) along an elevation gradient (3,000–4,200 m a.s.l.) in Annapurna Conservation Area, north-central Nepal. The results show that human disturbances and topographic factors contributed to the variation in density and life history traits. The overall density ranged between 0.56 ± 0.09 (Mean ± SE) and 2.48 ±  0.24 plants/m2 with highest mean density in the lower alpine and lowest in the subalpine population. The subalpine population was also characterized by lower investment in reproductive structures with lowest seed mass and low seed viability and fecundity. Among the environmental variables tested, harvesting, animal droppings and fire appeared to be the most important factors affecting density of different life stages of A. spicatum. The prevailing harvesting pattern is destructive as it involves uprooting of the whole plant and this appears to be a main reason for low recruitment and reduced density of the subalpine population. The level of disturbance decreased with increasing elevation. In terms of reproductive effort, the alpine population performed best. Our results indicate that the viability of A. spicatum populations depends on controlling over-harvesting and pre-mature harvesting of tubers and protecting younger life stages from grazing, trampling and fire. We therefore recommend that when formulating management guidelines, measures aiming to mitigate such anthropogenic disturbances should be considered.

scholarly journals Treeline dynamics with climate change at Central Nepal Himalaya

2013 ◽  
Vol 9 (5) ◽  
pp. 5941-5976 ◽  
Author(s):  
N. P. Gaire ◽  
M. Koirala ◽  
D. R. Bhuju ◽  
H. P. Borgaonkar
Keyword(s):  
Climate Change ◽  
Plant Density ◽  
Elevation Gradient ◽  
Age Distribution ◽  
Recruitment Rate ◽  
Conservation Area ◽  
Nepal Himalaya ◽  
The Past ◽  
Central Nepal ◽  
Tree Ring Data

Abstract. Global climate change has multidimensional impacts with several biological fingerprints, and treeline shifting in tandem with climate change is a widely observed phenomenon in various parts of the world. In Nepal several impacts of climate change on physical environments have been observed. However, studies on the biological impacts are lacking. This dendrochronological study was carried out at the treeline ecotone (3750–4003 m a.s.l.) in the Kalchuman Lake (Kal Tal) area of the Manaslu Conservation Area in central Nepal Himalaya with the aim to study the dynamic impact of climate change at the treeline. The study provides an insight into regeneration and treeline dynamics over the past 200 yr. Two belt transect plots (size: 20 m wide, >250 m long) were laid covering forest line, treeline as well as tree species Abies spectabilis and Betula utilis was done and their tree-cores were collected. Stand character and age distribution revealed an occurrence of more matured B. utilis (max. age 198 yr old) compared to A. spectabilis (max. age 160 yr). A. spectabilis contained an overwhelmingly high population (89%) of younger plants (<50 yr) indicating its high recruitment rate. Population age structure along an elevation gradient revealed an upward shifting of A. spectabilis at the rate of 2.61 m yr−1 since 1850 AD. The upper distribution limit of B. utilis was found stagnant in the past few decades. An increment in plant density as well as upward shifting in the studied treeline ecotones was observed. Thus, two species presented species-specific responses to climate change and much wider differences anticipated in their population status as climate continues to cha spectabilis correlated negatively with the mean monthly temperature of May–August of the current year and with September of the previous year. The regeneration of A. spectabilis, on the other hand, was positively related with May–August precipitation and January–April temperature of the current year. The reconstructed average summer temperature (May–August) using tree ring data revealed alternate period of cool and warm period with warming in the 2nd half of the 20th century. Further palynological and geochronological studies of sediments of the Kalchuman Lake would advance our understanding of past climatic trends and dynamics of the associated treeline and vegetation in the area.

scholarly journals Plant density influence on life history traits of a perennial herb in rocky outcrops, southeastern Brazil

2020 ◽  
Vol 75 ◽  
pp. e2020014-e2020014
Author(s):  
Guilherme Ramos Demetrio ◽  
Mario Eduardo Avelar Barbosa ◽  
Flávia de Freitas Coelho
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Plant Density ◽  
Perennial Herb ◽  
Southeastern Brazil ◽  
Rocky Outcrops

scholarly journals Treeline dynamics with climate change at the central Nepal Himalaya

2014 ◽  
Vol 10 (4) ◽  
pp. 1277-1290 ◽  
Author(s):  
N. P. Gaire ◽  
M. Koirala ◽  
D. R. Bhuju ◽  
H. P. Borgaonkar
Keyword(s):  
Climate Change ◽  
Minimum Temperature ◽  
Plant Density ◽  
Elevation Gradient ◽  
Age Distribution ◽  
Maximum Temperature ◽  
High Mountain ◽  
Nepal Himalaya ◽  
Central Nepal ◽  
The Impact

Abstract. Treeline shifting in tandem with climate change has widely been reported from various parts of the world. In Nepal, several impacts of climate change on the physical environment have been observed, but study on the biological impacts is lacking. This dendrochronological study was carried out at the treeline in the high mountain slope of Kalchuman Lake (3750–4003 m a.s.l.) area of Manaslu Conservation Area in the central Nepal Himalaya to explore the impact of climate change on the treeline dynamic. Two belt transect plots (size: 20 m wide, > 250 m long) were laid which included treeline as well as tree species limit. Ecological mapping of all individuals of dominant trees Abies spectabilis and Betula utilis was done and their tree cores were collected. Stand character and age distribution revealed an occurrence of more matured B. utilis (max. age 198 years) compared to A. spectabilis (max. age 160 years). A. spectabilis contained an overwhelmingly high population (89%) of younger plants (< 50 years) indicating its high recruitment rate. Population age structure along the elevation gradient revealed an upward shifting of A. spectabilis at the rate of 2.61 m year-1 since AD 1850. The upper distribution limit of B. utilis was found to be stagnant in the past few decades. An increment in plant density as well as upward shifting in the studied treeline ecotones was observed. The temporal growth of A. spectabilis was correlated negatively with the monthly mean and minimum temperature of June to September of the current and previous year. The regeneration of A. spectabilis, on the other hand, was positively correlated with August precipitation and monthly maximum temperature of the month of the current year. The growth and regeneration of A. spectabilis was more sensitive to maximum and minimum temperature rather than average temperature. The growth of the B. utilis was mainly limited by moisture stress during the pre-monsoon season. As these two species presented species-specific responses to climate change with differential pattern in regeneration condition, much wider differences are anticipated in their population status as climate continues to change throughout the century.

scholarly journals Variation in leaf biomass and fruit output of Juniperus indica along an elevation gradient in north-central Nepal

2017 ◽  
Vol 27 (1) ◽  
pp. 3-10
Author(s):  
A. Chapagain ◽  
R. P. Chaudhary ◽  
S. K. Ghimire
Keyword(s):  
Reproductive Output ◽  
Elevation Gradient ◽  
Plant Performance ◽  
Leaf Biomass ◽  
Allometric Relationships ◽  
North Central ◽  
Trunk Diameter ◽  
Central Nepal ◽  
Canopy Area ◽  
Non Destructive

 Biomass and reproductive output are important functional traits that influence aspects of plant performance. Measurements of these attributes by harvesting plant parts are often destructive and impractical. Therefore, non-destructive methods, based on allometric relationships, have been recommended for measuring plant biomass and reproductive output, particularly in the ecosystems where plant harvesting is not very practical or feasible. Here, we assessed the variation in the traits related to vegetative and reproductive performance (including plant height, trunk diameter, canopy area, leaf biomass and number of fruits set) among populations of Juniperus indica distributed along an elevation gradient in Manang district of the north-central Nepal, and finally determined the allometric relationships addressing the leaf biomass and the fruit output. The distribution range of J. indica was divided into lower- (3,350–3,580 m), mid- (3,650–3,880 m) and higher- (3,950–4,250 m) elevation classes where we made 54 sample plots of 10 m × 10 m size. In each plot, we recorded the number of individuals of J. indica classifying into seedling, juvenile and mature classes, and measured their vegetative traits and fruit output. Trunk diameter, leaf dry-weight and fruits set parameters spatially varied within the same elevation class. The individuals at the lower-elevation were larger in vegetative size with larger- trunk, height and canopy area, and produced higher leaf biomass and greater number of fruits as compared to those produced by the individuals situated at the mid- and higher-elevations. The regression analysis showed the strongest relationship between the canopy area and the leaf biomass. Thus, the use of outer canopy dimension is found to be the best option for estimation of leaf biomass of J. indica using non-destructive method.Banko Janakari, Vol. 27, No. 1, 2017, page: 3-10

scholarly journals Water immersion tolerance by larval instars of stable fly, Stomoxys calcitrans, L1758 (Diptera: Muscidae) impairs the fitness performance of their subsequent stages

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Steve B. S. Baleba
Keyword(s):  
Life History ◽  
Environmental Factors ◽  
Life History Traits ◽  
Water Immersion ◽  
Larval Instar ◽  
Stomoxys Calcitrans ◽  
Stable Fly ◽  
Life Stages ◽  
Larval Instars ◽  
First Instar

Abstract Background In holometabolous insects, environmental factors experienced in pre-imaginal life stages affect the life-history traits within that stage and can also influence subsequent life stages. Here, I assessed tolerance to water immersion by the larval instars of the stable fly, Stomoxys calcitrans L. (Diptera: Muscidae) and its impact on the life-history traits of their subsequent life stages. Results After submerging the three larval instars of S. calcitrans in distilled water, I found that the first instar larvae remained active for longer as compared to the second and third instar larvae. Also, the first instar larvae took a longer period to recover from the stress-induced immobility when removed from the water and returned to ambient temperature. When I followed the development of individuals of each larval instar that survived from water immersion, I found that their developmental time, weight, pupation percentage, adult emergence percentage and adult weight were negatively affected by this stressor. However, the weight of S. calcitrans adults developed from immersed first larval instar individuals was not affected by water immersion whereas their counterparts developed from immersed second and third larval instars had lower body weight. This suggests that in S. calcitrans, water immersion stress at the earlier stage is less detrimental than that experienced at late stages. Conclusion This study provides a comparative overview of the fitness consequences associated with water immersion stress during S. calcitrans larval ontogeny. The results prove that the fitness shift induced by water immersion in S. calcitrans is stage-specific. My results illustrate the importance of considering each larval instar when assessing the impact of environmental factors on holometabolous insect performance as these may be decoupled by metamorphosis.

scholarly journals There and back again: Spatial and temporal variation in the recruitment dynamics of an amphidromous fish

2021 ◽  
Author(s):  
◽  
Conor Stewart Bruce Neilson
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Phenotypic Variation ◽  
Early Life ◽  
Life Histories ◽  
Life History Traits ◽  
Early Life History ◽  
Phenotypic Traits ◽  
Life Stages ◽  
Larval Quality

<p>A primary goal of ecology is to identify the factors underlying recruitment variability, and how they may shape population dynamics. Recruitment is driven by the input of new individuals into a population. However, these individuals often show high diversity in phenotypic traits and life histories, and the consequences of this variation are poorly understood. Phenotypic variation is widespread among the early life stages of fish, and this variation may be influenced by events occurring across multiple life stages. While many studies have investigated phenotypic variation and its effect on population dynamics, comparatively few studies use an integrated approach that evaluates patterns and processes across multiple life history stages. Here I focus on a native amphidromous fish, Galaxias maculatus, and I explore patterns and consequences of phenotypic variation during larval stages, migratory stages, and post-settlement stages of this fish.  I explore variability in phenotypes and early life history traits of G. maculatus through both space and time. I use metrics derived from body size and otolith-based demographic reconstructions to quantify potentially important early life history traits. I found that cohorts of juvenile fish sampled later in the year were comprised of individuals that were older, smaller, and grew more slowly relative to fish sampled earlier in the year. I also found that two sampled sites (the Hutt River and the Wainuiomata River) showed different temporal trends, despite their close geographical proximity.  I then investigated whether phenotype was related to mortality. I used otolith-based traits to characterise larval ‘quality’ for individual fish. I then calculated the average larval quality for discrete cohorts of fish, and used catch-curve analysis to estimate mortality rates for these cohorts. I investigated the overall relationship between quality and mortality, and compared the trend between two sites. My results indicate that phenotype and mortality were not significantly correlated. However, this inference may be limited by low statistical power; the non-significant trends suggest that the relationship might be negative (i.e., larvae of higher quality tend to have lower rates of mortality). This trend is typical of systems where population expansion is limited by food rather than predators.  I then investigated whether phenotypic traits in the juvenile cohorts were correlated with traits in adult cohorts. I resampled the focal populations ~6 months after sampling the juvenile stages (i.e., targeting fish from sampled cohorts that had survived to adulthood), and I used data from otoliths to reconstruct life history traits (hatch dates and growth histories). I compared adult life history traits to the traits of discrete juvenile cohorts.  My results suggest that fish that survived to adulthood had comparatively slower growth rates (reconstructed for a period of larval/juvenile growth) relative to the sampled juvenile cohorts (where growth rate was estimated for the same period in their life history). I also found that the distributions of hatch dates varied between sites. Fish that survived to adulthood at one site hatched later in the breeding season, while adult stages from the other site had hatch dates that were distributed across the entire breeding season. Both hatch date and growth rate are likely linked to fitness, and their interaction may have influenced patterns of survival to adulthood. These results provide evidence for carry-over effects of larval phenotype on juvenile success  Collectively my thesis emphasises the importance of phenotype and life history variability in studies of recruitment. It also highlights the importance of spatial scale, and how biological patterns may differ between geographically close systems. Some of the general inferences from my study may extend to other migratory Galaxiid species, and perhaps more generally, to many species with extensive larval dispersal. Finally, my work highlights potentially important interactions between phenotypes, life histories, and mortality, which can ultimately shape recruitment, and the dynamics of populations.</p>

scholarly journals Malaria mosquitoes acquire and allocate cattle urine to enhance life history traits

2020 ◽  
Author(s):  
Mengistu Dawit ◽  
Sharon R. Hill ◽  
Göran Birgersson ◽  
Habte Tekie ◽  
Rickard Ignell
Keyword(s):  
Life History ◽  
Anopheles Arabiensis ◽  
Life History Traits ◽  
Physiological State ◽  
Management Strategies ◽  
Life Stages ◽  
Host Seeking ◽  
Trade Offs ◽  
Vector Management ◽  
Malaria Mosquitoes

AbstractNutrient acquisition and allocation integrate foraging and life-history traits in insects. To compensate for the lack of a particular nutrient at different life stages, insects may acquire these through supplementary feeding on e.g., vertebrate secretions, in a process known as puddling. The mosquito Anopheles arabiensis emerges undernourished, and as such, requires nutrients for both metabolism and reproduction. Host-seeking and blood-fed An. arabiensis are attracted to the natural and synthetic odour of cattle urine, which signals a source of nutrients, but not the presence of a host or oviposition site. Females actively imbibe cattle urine, and its main nitrogenous compound, urea, and allocate these resources according to life history trade-offs to flight, survival or reproduction, as a function of physiological state. As a consequence, this behaviour affects vectorial capacity by increasing daily survival and vector density, and thus should be considered in future models. Future vector management strategies are discussed.

scholarly journals There and back again: Spatial and temporal variation in the recruitment dynamics of an amphidromous fish

2021 ◽  
Author(s):  
◽  
Conor Stewart Bruce Neilson
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Phenotypic Variation ◽  
Early Life ◽  
Life Histories ◽  
Life History Traits ◽  
Early Life History ◽  
Phenotypic Traits ◽  
Life Stages ◽  
Larval Quality

<p>A primary goal of ecology is to identify the factors underlying recruitment variability, and how they may shape population dynamics. Recruitment is driven by the input of new individuals into a population. However, these individuals often show high diversity in phenotypic traits and life histories, and the consequences of this variation are poorly understood. Phenotypic variation is widespread among the early life stages of fish, and this variation may be influenced by events occurring across multiple life stages. While many studies have investigated phenotypic variation and its effect on population dynamics, comparatively few studies use an integrated approach that evaluates patterns and processes across multiple life history stages. Here I focus on a native amphidromous fish, Galaxias maculatus, and I explore patterns and consequences of phenotypic variation during larval stages, migratory stages, and post-settlement stages of this fish.  I explore variability in phenotypes and early life history traits of G. maculatus through both space and time. I use metrics derived from body size and otolith-based demographic reconstructions to quantify potentially important early life history traits. I found that cohorts of juvenile fish sampled later in the year were comprised of individuals that were older, smaller, and grew more slowly relative to fish sampled earlier in the year. I also found that two sampled sites (the Hutt River and the Wainuiomata River) showed different temporal trends, despite their close geographical proximity.  I then investigated whether phenotype was related to mortality. I used otolith-based traits to characterise larval ‘quality’ for individual fish. I then calculated the average larval quality for discrete cohorts of fish, and used catch-curve analysis to estimate mortality rates for these cohorts. I investigated the overall relationship between quality and mortality, and compared the trend between two sites. My results indicate that phenotype and mortality were not significantly correlated. However, this inference may be limited by low statistical power; the non-significant trends suggest that the relationship might be negative (i.e., larvae of higher quality tend to have lower rates of mortality). This trend is typical of systems where population expansion is limited by food rather than predators.  I then investigated whether phenotypic traits in the juvenile cohorts were correlated with traits in adult cohorts. I resampled the focal populations ~6 months after sampling the juvenile stages (i.e., targeting fish from sampled cohorts that had survived to adulthood), and I used data from otoliths to reconstruct life history traits (hatch dates and growth histories). I compared adult life history traits to the traits of discrete juvenile cohorts.  My results suggest that fish that survived to adulthood had comparatively slower growth rates (reconstructed for a period of larval/juvenile growth) relative to the sampled juvenile cohorts (where growth rate was estimated for the same period in their life history). I also found that the distributions of hatch dates varied between sites. Fish that survived to adulthood at one site hatched later in the breeding season, while adult stages from the other site had hatch dates that were distributed across the entire breeding season. Both hatch date and growth rate are likely linked to fitness, and their interaction may have influenced patterns of survival to adulthood. These results provide evidence for carry-over effects of larval phenotype on juvenile success  Collectively my thesis emphasises the importance of phenotype and life history variability in studies of recruitment. It also highlights the importance of spatial scale, and how biological patterns may differ between geographically close systems. Some of the general inferences from my study may extend to other migratory Galaxiid species, and perhaps more generally, to many species with extensive larval dispersal. Finally, my work highlights potentially important interactions between phenotypes, life histories, and mortality, which can ultimately shape recruitment, and the dynamics of populations.</p>

scholarly journals New record on Asiatic Golden Cat Catopuma temminckii Vigors & Horsfield, 1827 (Mammalia: Carnivora: Felidae): photographic evidence of its westernmost distribution in Gaurishankar Conservation Area, Nepal

2020 ◽  
Vol 12 (2) ◽  
pp. 15256-15261
Author(s):  
Narayan Prasad Koju ◽  
Bijay Bashyal ◽  
Bishnu Prasad Pandey ◽  
Shankar Thami ◽  
Man Kumar Dhamala ◽  
...  
Keyword(s):  
Protected Area ◽  
New Record ◽  
Camera Trap ◽  
Single Camera ◽  
Conservation Area ◽  
North Central ◽  
Central Nepal ◽  
Photographic Evidence ◽  
Near Future ◽  
The Himalaya

The Asiatic Golden Cat Catopuma temminckii is poorly known in Nepal and was previously recorded only twice in the eastern part of the country.  We conducted a camera trap survey in the Lapchi Valley (32km2) of Gaurishankar Conservation Area (GCA), a protected area in north-central Nepal, from October 2018 to April 2019. Eleven cameras were deployed to record mammalian diversity in a 2×2 km2 grid across Lapchi block of GCA.  During the study period, four photos and three videos (each of 10 seconds length) of Asiatic Golden Cats were recorded at an elevation of 2,540m at a single camera trap station.  This is the first photographic record of Asiatic Golden Cat in this region of Nepal extending the distribution of the species further west in the Himalaya.  A more detailed study on its distribution, population size and behaviour is warranted in the near future to implement appropriate conservation measures.  

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