Population ecology and field conservatory of Carum carvi (Linn.) in the Indian cold desert region

Present work pertains to the cytological investigations performed in Ranunculus laetus for the first time from Indian cold deserts and adjoining high hills of North-west Himalayas which covers Chamba, Kinnaur, Kullu and Lahaul-Spiti districts of Himachal Pradesh. We here also report for the first time the presence of 1 B-chromosome in two accessions studied from Dalhousie hills. Twelve accessions scored presently from these regions uniformly shared the same meiotic chromosome number, n=14 and existed at tetraploid level (based on x=7). Of these, eight accessions showed abnormalities during male meiosis, such as pollen mother cells (PMCs) involved in chromatin transfer at different stages of meiosis, chromosome stickiness, pycnotic chromatin material, out of plate bivalents at metaphase-I, nonsynchronous disjunction of some bivalents, and laggards at anaphases/telophases. Consequent to these meiotic irregularities, microsporogenesis in meiocytes is abnormal characterized by the presence of dyads, polyads, and micronuclei and included micronuclei in sporads. These irregularities during meiotic course resulted into varying percentage of pollen sterility (9–31%) and pollen grains of heterogeneous sizes. The remaining four accessions showed regular meiotic course, normal microsporogenesis and nearly cent percent pollen fertility (97.90–100%). Key words: B-chromosomeChambacytomixisKinnaurKullulaggards and bridgesLahaul-Spiti

Astragalus tricarinatus A.Gray is a federally-listed short lived perennial herb endemic to southern California. Its primary habitat is along the ecotone of the Mojave and Colorado Deserts in the San Bernardino and Little San Bernardino Mountains between 390 and 1525 m. Discovery of this species' upland habitat has prompted research into the ecology of populations across its range, as the life history and threats may be different from those of the previously-known wash populations. Our study sought to further document A. tricarinatus distribution and abundance within its range, as well as quantify impacts to its growth and reproductive efforts associated with co-occurring native and invasive plant species. We mapped all known localities in our study area on aerial imagery then used this to visually recognize its typical edaphic habitat and identify new potential sites. Where A. tricarinatus was found, we established plots in which plant size, the number of reproductive structures, and microhabitat characteristics were recorded. Two new occurrences (defined here as >1 km away from known localities) were recorded within its existing range as well as a previously undocumented locality between two known occurrences containing an estimated 2600 plants. Most plants were found on south and east aspects, and on slopes ranging from 30–45°. We found that increases in invasive cover correlated with a decrease in production of reproductive structures. As a federally-listed species occurring in steep, remote habitats with few threats, these findings suggesting an association between invasive species presence and reduced reproductive structures should be further investigated experimentally, as they affect population dynamics and conservation of this species.

Psychrophilic fungi are a critical biotic component in cold deserts that serves a central role in nutrient recycling and biogeochemical cycles. Despite their ecological significance, culture-independent studies on psychrophilic mycobiome are limited. In the present study, the fungal diversity patterns across the Drass, an Indian cold desert in the Himalaya, were indexed by targeted amplicon pyrosequencing (ITS). In the Drass dataset, Ascomycota was represented by 92 genera, while 22 genera represented Basidiomycota. The most abundant genus was Conocybe (20.46%). Most of the identified genera were reported in the literature to be prolific extracellular hydrolytic enzyme producers. To identify whether the Drass fungal assemblages share similarities to other cold deserts, these were further compared to Antarctic and Arctic cold deserts. Comparative analysis across the three cold deserts indicated the dominance of Dikarya (Ascomycota and Basidiomycota). The observed alpha diversity, Shannon index as well as Pielou's evenness was highest in the Antarctic followed by Drass and Arctic datasets. The genera Malassezia, Preussia, Pseudogymnoascus, Cadophora, Geopora, Monodictys, Tetracladium, Titaea, Mortierella, and Cladosporium were common to all the cold deserts. Furthermore, Conocybe was represented predominantly in Drass. Interestingly, the genus Conocybe has not been previously reported from any other studies on Antarctic or Arctic biomes. To the best of our knowledge, this is the first fungal metagenome study in Drass soil. Our analysis shows that despite the similarities of low temperature among the cold deserts, a significant differential abundance of fungal communities prevails in the global cold deserts.

On Limits to Seed Production

Numbers of nestlings fledged per pair per season were calculated for 35 species of passerine birds in four localities from data on length of breeding season, clutch size, nesting mortality, and length of nest cycle. Mean numbers of nestlings fledged was 6.42 for 12 woodland and edge species in Kansas, 4.33 for 8 species in lower Sonoran desert habitat in Arizona, 2.36 for 6 species in humid forest and second-growth habitats in Costa Rica, and 4.80 for 9 species in a desert scrub habitat in Ecuador. The data were analyzed by multiple correlation and stepwise multiple regression to determine the contribution of the variables to variation in the number of young fledged from one species to another in each locality. Variations in season length, clutch size, and breeding success were important components in variation in numbers of young fledged in Kansas, but length of nest cycle, being positively correlated with both clutch size and nest success, had the strongest correlation with the number of young fledged. In Arizona and Costa Rica, variation in breeding success held the key to predicting variation in number of young fledged, whereas in Ecuador season length and clutch size were the critical variables. The analyses suggest that data on production of young and the factors that cause production to vary from one species to another would add immensely to our understanding of the population ecology of birds.-Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19174. Accepted 1 July 1975. Ornithologists have pondered the significance of clutch size in birds for nearly three decades without fully resolving the factors responsible for its variation among species and regions. Although Skutch (1949) linked the evolution of clutch size to adult mortality and population turnover rate, population biologists have only re- cently placed clutch size in a demographic context. For example, not until 1961 did Drury point out that the production of young by a pair of birds during a breeding season depends on the number of broods raised as well as clutch size. Cody (1971) and Ricklefs (1973) treated avian demography more fully and demonstrated the use of life table analyses to compare species. Although breeding biology and mortality have been investigated in scores of de- tailed field studies, complete life tables have been constructed for only a handful of species. Of the statistics required to complete a life table, the annual production of young is one of the most difficult to obtain. Observation of individually marked birds yields relatively few data per hour of effort (for example see Nice 1937, Snow 1958). Furthermore, estimates of mean annual productivity obtained from direct observa- tion have large probable errors (wide confidence limits) owing to the great variation between individuals. Annual productivity can be calculated indirectly from clutch size, breeding success, nest cycle length, and length of breeding season (Ricklefs 1970). These data are more readily obtained than direct measures of breeding pro- ductivity. Furthermore, data from different studies may be combined to calculate the annual production of a species. In this paper we calculate annual production (fledglings per pair of adults) for various passerine birds in two temperate and two tropical localities. The data are

The species richness, distribution and community structure in cold desert regions across the world are poorly understood because of their inaccessibility and remoteness. Similarly, the structure and composition of forest resources, including other management units (i.e., agroforestry and forestry systems), have hardly been studied in the cold desert of the Lahaul valley. However, such information is a prerequisite to understanding the trends and changes in the vegetation distribution under global climate change scenarios, especially considering the sensitivity of plant species in high-altitude areas of the Himalayan region. High anthropogenic activity has exerted tremendous pressure on available forest resources, including other management units in the cold desert of the Lahaul valley. Standard ecological methods were used to obtain an ecological (i.e., status, structure, composition and vegetation patterns) understanding of the region for biodiversity conservation and environmental sustainability. The present study was aimed at understanding the trend, structure and composition of plant species in the cold desert region of the western Himalaya. A total of 64 species (27 trees and 37 shrubs) of vascular plants were recorded in the present study. Tree diversity demonstrated greater variation along the gradients and slope aspects. Salix fragilis trees, with a 102 tree ha−1 density and a few trees of Populus nigra, were found to be sparsely distributed under the agroforestry system on the south-facing slopes in Khoksar. In Jahlma, Salix fragilis grew in an agroforestry system with a density of 365 tree ha−1. However, in Hinsa, Juniperus polycarpos was a dominant tree species in the agroforestry system, with a density of 378 tree ha−1. On the north-facing slopes in Kuthar, a higher number of trees and bushes were present due to natural regeneration maintained by farmers along the edges of terraced agricultural fields. The south-facing slopes showed a relatively lower species richness and diversity as compared to north-facing slopes at similar locations due to relatively less favourable growth conditions under sun-exposed, extremely xeric soil conditions. The highest level of species turnover was found between the altitudes of 2400 m and 3000 m. Betula utilis showed the highest adaptability at higher altitudes (>3500 m). The vegetation analysis results and information generated in the present study are useful for gaining an ecological understanding of the cold desert ecosystem in the Lahaul valley. Sustainable forest resource management, including other management units (e.g., agroforestry and forestry systems), is crucial for improving the vegetation pattern, structure and function of the cold desert ecosystem, thereby contributing to climate change mitigation, adaptation, biodiversity and ecosystem service conservation.

Deserts are the most abundant terrestrial biome on Earth, and microbial processes assume a major role since environmental stress severely limits higher plant and animal life. A major hurdle to developing an understanding of microbial ecology in deserts has been the lack of knowledge at the fundamental biodiversity level. This is due to lack of research focus and also the inherent bias in ‘traditional’ microbial diversity estimates based upon cultivation. In this thesis an evaluation of culture-independent approaches employing both DNA and RNA from environmental samples was made with comparison to more traditional cultivation techniques. These were then applied to soils from hot and cold deserts, and along stress gradients from semi-arid to hyper-arid.\n\nA literature review was first conducted to assess the extent of current knowledge and identify critical knowledge gaps. The scientific study was then carried out as follows. The second chapter presents an evaluation of fungal taxa using cultivation, DNA and RNA based techniques. The findings indicated major taxa are revealed in all approaches, yet differences in less abundant taxa occur. The third chapter describes fungal assemblages in the soils of the McMurdo Dry Valleys, a cold polar desert. In this study, RNA based approaches tracked active fungal assemblages, whilst DNA and cultivation revealed additional taxa. Chapter four analyzed microbial communities in the Thar Desert, a hot monsoon desert in India. This study revealed a diverse community that comprised known desiccation-tolerant taxa but also a phylogenetically broad range of bacteria, archaea and eukarya. Chapter 5 focuses on the delineation of total versus active microorganisms in environmental samples from the hot deserts. As with the initial experiments, this revealed that total and active assemblages track each other broadly in desert soils. A synthesis of the study revealed that certain common microbial phyla are likely well-adapted to xeric stress, although distinct hot and cold desert assemblages also develop. For such low-diversity systems it is likely that DNA-based approaches are reasonable tools for diversity analysis, and will be especially useful in arid systems when long periods of inactivity may confound attempts to estimate active populations. Broader significance of the study includes an increased appreciation of eukaryotic microbial presence in arid soils, and how latent soil microbiota may act as a reservoir for development of future microbial macro-structures (e.g. soil crust) that function in soil stabilization, and should therefore be included in conservation planning for deserts.

For the restoration and rehabilitation of a species, comprehensive information on the ecological elements and potential habitats are essentially required to the conservationists. This has necessitated initiating studies on habitat and population ecology of the threatened species. Keeping this in view, population ecology and niche modelling of endangered Arnebia euchroma in Himachal Pradesh was studied. Total 49 populations of A. euchroma were studied between 3325-4587m amsl in the Lahaul and Spiti and Kinnaur districts of Himachal Pradesh. Most of the populations (25) were found in steep slope and fall in east, north, north-east, north-west, south, south-east, south-west and west aspects. Maximum populations (11) were represented in the east aspect, followed by north and west (9 each) and northeast and northwest (6 each) aspects. Among the populations, richness of shrubs ranged from 1–7 and herbs 4–36; total shrubs density 2–119 Ind 100 m−2; total herbs density 460–7055 Ind 100 m−2; Concentration of dominance for shrubs 0.26–1 and herbs 0.05–0.37 and Species diversity (H’) for shrubs 0.0–1.56 and herbs 1.26–3.29. Biological features, aspects, slope and pressure contributed to the critical population status of the A. euchroma. The particular geographical distribution (2022 km2) under semi-arid conditions of the species indicated its habitat specificity. The present investigation revealed that A. euchroma populations showed fragmented pattern of distribution in the cold desert ecosystem. Therefore, re-introduction of A. euchroma in highly suitable habitat i.e., north-western gentle dry slope with high pH (alkaline soils) and low total nitrogen, moisture, carbon and organic matter is suggested.

Assessment of fuelwood diversity and consumption patterns in cold desert part of Indian Himalaya: Implication for conservation and quality of life

Climate change perception survey is a method designed to gain insights on people’s perspectives of the changing climate and recognizing important factors, complexities, and limitations towards a climate-conscious conduct. Such surveys are particularly important in ecologically sensitive transitional climatic zones but logistically difficult terrains, where meteorological data is scarce and minor changes in climatic parameters can have unanticipated consequences for the local ecosystem. The current research is focused on one of such climate-sensitive areas, in the northwestern Himalaya. A binary question-based survey (interview) was conducted in the high-altitude, cold desert region – Ladakh, which covered all the five subdivisions of the union territory. According to the climate perception data, the majority of respondents are aware of climate change or global warming regardless of age, gender, and background. The exponential growth in tourist inflow over the last two decades (attributed to ‘war tourism’) equates with the increasing number of vehicles and is well perceived by the locals. Approximately 86 percent of respondents believe that humans have had a negative impact on the environment. They appear to be quite optimistic about curbing the effects of climate change, with approximately 91 percent willing to participate in mitigation efforts. The results of this study show an overall agreement between people’s perceptions of climate change and the scientific evidence of these changes. These findings are eventually intended to serve as an important parameter in developing adaptation and mitigation strategies in this ecologically sensitive and vulnerable region.

India’s arid region can be divided into a hot arid zone in the west, inhabited by the Aryans, and a cold arid region in the north India, inhabited by indigenous tribal communities. This article deals with biodiversity issues in India’s cold desert region.

In the last 25 years thousands of new meteorites were recovered in the “cold deserts” of Antarctica and in the hot deserts of Australia, New Mexico, North Africa, and Oman. Based on the findings of many spectacular samples new meteorite classes could be defined. Considering the undifferentiated chondrites, the new class of the Rumuruti (R-) chondrites was established and the carbonaceous chondrites gained three more subgroups (CR-, CH-, and CK-chondrites). Also, among the achondrites new meteorite classes were defined in recent years (angrites, brachinites, and the primitive achondrite classes of acapulcoites, winonaites, and lodranites). Certainly, the most spectacular discovery among the cold and hot desert meteorites was the recognition of the Lunar meteorites. In addition, the number of Martian meteorites has been significantly increased based on successful meteorite search.

Presently, detailed cytological investigations have been carried out in 4 accessions of Anemone rivularis Buch.-Ham. ex DC, collected from the cold deserts of Lahaul-Spiti, Kinnaur, and Kullu districts of Himachal Pradesh (India). The phenomenon of cytomixis involving chromatin transfer among proximate pollen mother cells (PMCs) during male meiosis is recorded for the first time in the species. The effects of cytomixis on meiosis and pollen grains have also been discussed. In spite of the existence of intraspecific aneuploid and polyploid cytotypes (2n=14, 16, 24, 28, 48), all the accessions of the species unequivocally share the same diploid chromosome number, 2n=16. The accession studied from Kothi (Kullu) shows perfectly normal meiotic behaviour, cent per cent pollen fertility and uniform sized pollen grains. However, the accessions analyzed from Keylong and Kishori (Lahaul-Spiti) and Sangla (Kinnaur) show the phenomenon of cytomixis involving chromatin transfer among proximate PMCs, and associated meiotic abnormalities like chromosome stickiness, laggards and bridges at anaphase/telophase, micronuclei, some pollen malformation and pollen grains of heterogeneous sizes.

Thalictrum foetidum L. (Ranunculaceae), a morphologically variable and widely distributed species of temperate and alpine Himalayas is worked out cytologically for the first time from India. Earlier studies from outside India were restricted to chromosome counts and karyotypic analysis. We studied the male meiosis, microsporogenesis and pollen viability in the wild accessions from the cold deserts of Lahaul-Spiti, Kinnaur and Pangi Valley of Himachal Pradesh. Present cytomorphological surveys in the species record the existence of two distinct morphotypes involving plant size; colour and size of leaf/leaflet; dentation of leaflet lobes; and degree of leaf pubescence. All the accessions in the two morphovariants share the same meiotic chromosome number (n = 21) and adds a new intraspecific hexaploid cytotype. The accessions show the phenomenon of cytomixis involving transfer of chromatin material among proximate pollen mother cells (PMCs) and associated meiotic abnormalities like, out of plate bivalents, interchromosomal connections, and laggards, bridges and micronuclei at anaphases/telophases. Microsporogenesis results into abnormal sporads (tetrads with micronuclei, dyads, triads and polyads). The products of such sporads resulted into some pollen sterility and pollen grains of heterogeneous sizes. The persistent occurrence of phenomenon of cytomixis and associated meiotic abnormalities and consequently pollen sterility and pollen grains of heterogeneous sizes in the hexaploid cytotype of T. foetidum seems to be under some genetic factors associated with the genome.

In the last 15 years, more than 2700 meteorites have been recovered and officially classified from the Atacama Desert. Although the number of meteorites collected in the Atacama has risen, the physical and climatic properties of the dense collection areas (DCAs) have not been fully characterized. In this article, we compiled the published data of all classified meteorites found in the Atacama Desert to (i) describe the distribution by meteorite groups, (ii) compare the weathering degree of chondrites among different Atacama DCAs and other hot and cold deserts, and (iii) determine the preservation conditions of chondrites in the main Atacama DCAs in relation with the local climatic conditions. The 35 DCAs so far identified in the Atacama Desert are located in three main morphotectonic units: The Coastal Range (CR), Central Depression (CD), and Pre‐Andean Range/Basement. A comparison with reported weathering data from other cold and hot deserts indicates that the mean terrestrial weathering of Atacama chondrites (W1–2), displays less alteration than other hot deserts (W2–3) and resembles the weathering distribution of the Antarctic meteorites (W1–2). The highest abundance of Atacama chondrites with low weathering (≤W2) is localized in the CD (78.8%, N = 1435), which is protected from the coastal fog influence and seasonal rainfalls and displays the oldest surfaces in the Atacama Desert. The morphogenetic classification based on present‐day temperatures and precipitations of the main Atacama DCAs reveals similar regional/subregional climatic conditions in the most productive areas and a truly productive surface for meteorite recovery between 5% and 58% of the quadrangles formally defined for each Atacama DCA. Our morphogenetic classification lacks consideration of some meteorological parameters such as the coastal fog, so it cannot fully explain the differences in weathering patterns among CR chondrites. Future studies of chondrite preservation in the Atacama DCAs should consider other meteorological variables such as relative humidity, specific humidity, or dew point, in combination with exposure ages of meteorites and its surfaces.