Morphology of the male reproductive system, chromosome behaviors during meiosis and spem tail structures in Homoptera and Heteroptera are compared in this paper. The sheathed testis is found in Fulgoroidea and Heterop...Morphology of the male reproductive system, chromosome behaviors during meiosis and spem tail structures in Homoptera and Heteroptera are compared in this paper. The sheathed testis is found in Fulgoroidea and Heteroptera, and unsheathed testis occurs in Cicadoidea, Cicadelloidea, Cercopoidea, Membracoidea, Psyloidea, Aphidoidea, Aleyrodoidea and Coccoidea. The testis also can be divide into three types by the shape of testicular follicles. The sphere-shaped type is found in Cicadoidea, Cicadelloidea, Cercopoidea, Membracoidea, Aphidoidea and Aleyrodoidea, the tube-shaped type observed in Fulgoroidea, Psyloidea and Coccoidea, and the lamella-shaped type represented by Heteroptera. It is suggested the unsheathed testis may be the primitive type in Homoptera. Meiosis can be divided into 6 type at least, i.e. 1） Cicadoid type; 2） Fulgoroid type; 3） Psyloid type; 4） Aphidoid type; 5） Aleyrodoid type; and 6） Coccoid type. At least four groups exhibit a diffuse stage during meiosis prophase l, they are Psyloidea, Fulgoroidea, Coccoidea and Heteroptera. Sperm tail structures are similar to those reported from other insects with a typical 9＋9＋2 axoneme except that in Aleyrodoidea and Coccoidea whose sperm tail is degenerated.展开更多
Ontogeny and metamorphic. development of female reproductive organs in Ephedra sinica Stapf were surveyed. At the end of April, female cones began to initialize from the vegetative buds. Pollination occurred in mid-Ma...Ontogeny and metamorphic. development of female reproductive organs in Ephedra sinica Stapf were surveyed. At the end of April, female cones began to initialize from the vegetative buds. Pollination occurred in mid-May and seeds matured at the beginning of July. The ontogenetic pattern of female reproductive organs of E. sin ca is basically similar to that of E. distachya L. The foliar nature of the outer envelope of the ovule in Ephedra is corroborated. Reduction of ovule number as a tendency of speciation in the genus is substantiated by the occurrence of tri-ovulate cones coupled with comprehensive characters of the genus. The metamorphic patterns as well as the leaf nature of the outer envelope indicate that female cones of Ephedra are compound while the female reproductive units of the ovulate cone have been reduced from secondary reproductive shoots similar to those of cordaites by phylogenetic transformation, fusion and reduction. Each fertile bract together with its axillary female reproductive unit composed the Bract Scale and Seed Scale Complex of Ephedra.展开更多
[Objective] The behavior of eating, drinking, defecating and peeing of 1 500 pigs in a large-scale microbial fermentation bed-equipped piggery was observed. We hoped to find some simple indicators that could reflect t...[Objective] The behavior of eating, drinking, defecating and peeing of 1 500 pigs in a large-scale microbial fermentation bed-equipped piggery was observed. We hoped to find some simple indicators that could reflect the health status of swinery and to provide experience for the swinery performance management in large-scale microbial fermentation bed-equipped piggery. [Method] The body weight （BW）, daily BW gain, feed intake and other indicators of different-day-old pigs were recorded in details. Based on the recorded data, the models between BW, BW gain, average daily feed intake and feed/gain ratio and growth days （d） were established. In addition, the incidences of pox-like macula （dermatitis）, diarrhea （gastrointestinal disease）, cough （respiratory disease）, stiff pig （malnutrition）, conjunctivitis （eye disease） and foot inflection （trauma） among fattening pigs were also investigated. [Result] The BW range, average BW, daily BW gain, breeding days, daily feed intake range, average daily feed intake, staged feed intake, accumulated feed intake, feed/gain ratio and accumulated feed/gain ratio of different-day-old pigs were studied, respectively. Four dynamic models were established for the growth of pigs： （1） the BW （y）-age （x） mod- el： y=0.758 9x-19.883 （3=0.993 7）; （2） the BW gain （y）-age （x） model： y=1.039 5x05051 （F=0.885 4）; （3） the average daily feed intake （y）-age （x） model： y=0.023 5x-0.334 3 （F=0.991 7）; （4） the feed/gain ratio （y）-age （x） model： y=0.022x＋0.427 8 （P=0.988 5）. Based on these models, the corresponding theoretical growth value of pigs at different growth stage could be predicted. The main diseases occurred among the swinery in the large-scale microbial fermentation bed piggery included pox-like macula （dermatitis）, diarrhea （gastrointestinal disease）, cough （respiratory disease）, stiff pig （mal- nutrition）, conjunctivitis （eye disease） and foot inflection （trauma）. The deadly infec- tious diseases had been not found among the pigs. [Conclusion] When the actual BW, BW gain, average daily feed intake and feed/gain ratio were all lower than the theoretical values predicted by the models, the management should be enhanced. The average daily feed intake of 60 to 65-day-old pigs was lower than the theoretic value, indicating that the pigs could not adapt nicely to the fermentation bed at the very early stage. When the pigs grew up to 70 to 75 d old, the average daily feed intake was higher than the theoretical value, indicating that the pigs had adapted to the fermentation bed. In particularly, average daily feed intake of 75-day-old pigs was higher than the theoretical value by 21%. It was suggested the fermentation bed was conducive to the growth of pigs. Considering the occurrence of diseases among pigs, the overall incidence was relatively low. The incidence of each disease was all lower than 10% with little difficulty in treating. If the management of mattress was strength- ened, such as paying attention to feeding and keeping water clean, many diseases could heal by themselves.展开更多
Neural stem cells （NSCs） constitute the cellular basis for embryonic brain development and neurogenesis. The process is regulated by NSC niche including neighbor cells such as vascular and glial cells. Since both va...Neural stem cells （NSCs） constitute the cellular basis for embryonic brain development and neurogenesis. The process is regulated by NSC niche including neighbor cells such as vascular and glial cells. Since both vascular and glial cells secrete vascular endothelial growth factor （VEGF） and basic fibroblast growth factor （bFGF）, we assessed the effect of VEGF and bFGF on NSC proliferation using nearly homogeneous NSCs that were differentiated from mouse embryonic stem cells. VEGF alone did not have any significant effect. When bFGF was added, however, VEGF stimulated NSC proliferation in a dose-dependent manner, and this stimulation was inhibited by ZM323881, a VEGF receptor （Flk-1）- specific inhibitor. Interestingly, ZM323881 also inhibited cell proliferation in the absence of exogenous VEGF, suggesting that VEGF autocrine plays a role in the proliferation of NSCs. The stimulatory effect of VEGF on NSC proliferation depends on bFGF, which is likely due to the fact that expression of Flk-1 was upregulated by bFGF via phosphorylation of ERK1/2. Collectively, this study may provide insight into the mechanisms by which microenvironmental niche signals regulate NSCs.展开更多
In the past decades, a lot of advances in understanding the biochemistry and physiology of the pineal gland have been made. There is evidence that it interacts with many endocrine as well as non-endocrine tissues to i...In the past decades, a lot of advances in understanding the biochemistry and physiology of the pineal gland have been made. There is evidence that it interacts with many endocrine as well as non-endocrine tissues to influence their metabolic activity modulating many organs and functions. Melatonin is secreted by the pineal gland in the brain and plays an important role in regulating the neuroendocrine system. This hormone is one of the major role players in the regulation of the circadian sleep-wake cycle. It is normally released from the pineal gland during the night in response to environmental changes in light. Studies have shown that melatonin plays a role in the regulation of many reproductive processes such as puberty, gonadal function, and pregnancy. Beside these, melatonin has been shown to be able to directly neutralize a number of free radicals and reactive oxygen and nitrogen species. The main objective of this review is to provide comprehensive information about the new developments in melatonin research regarding its role in reproduction. A review of international scientific literature was done and a question-and-answer format was used in an attempt to convey comprehensive information in a simple manner. This review discusses evidence currently available relating to the effect of melatonin on reproductive processes. It deliberates the mechanism of action of melatonin, its effect on puberty, testicular and ovafunction, pregnancy, and oxidative stress. A growing body of scientific evidence is suggesting that melatonin plays an important role in reproductive function. It is therefore imperative to highlight the beneficial effects of this hormone in improving the reproductive processes.展开更多
Fruitlet abscission （cherelle wilt） is a major factor contributing to lower productivity of cacao plantation in Indonesia. An attempt was made to reduce such cherelle wilt by spraying plant growth retardants （PGRs...Fruitlet abscission （cherelle wilt） is a major factor contributing to lower productivity of cacao plantation in Indonesia. An attempt was made to reduce such cherelle wilt by spraying plant growth retardants （PGRs） on cacao trees at about 10 weeks before flowering session. The treatment was repeated every three weeks. Both the flowering initiation time and the number of flowers on the treated trees were improved significantly. With the most effective composition, flowers were initiated at 24 days after spraying （DAS）, where as the flowering initiation was 11-day later in the controls. At the 35 DAS, the chlorocholine chloride （CCC） 2,000 treatment induced about 20-80 folds more flowers than the controls. Extended observation was made to assess the treatment effect on the fruiting capacity. The treatments were found to improve fruiting ability by increasing the number of fruits set on the trees and shortening the time for fruit setting. At 20 weeks after the first spraying （WAS） there were on average 12.57 fruits per CCC 2,000-treated tree, as opposed to only 4.14 fruits per untreated tree. Analyses of the metabolites content in the flower cushions of the trees indicated that the reproductive growth is significantly correlated with the increased metabolites particularly the reduced sugar. Exogenous addition of sucrose to the PGR treatment gave greater improvement mainly in the fruiting. In conclusion, foliar spray of CCC induces flowering of cacao tress in the field that leads to improve the fruitlets productivity.展开更多
Histological characteristics of gametogenesis of two kinds of scallops, gonochoric Chinese scallop, Chlamys farreri and hermaphroditic bay scallop, Argopecten irradians were investigated in this study. Spermatogenesis...Histological characteristics of gametogenesis of two kinds of scallops, gonochoric Chinese scallop, Chlamys farreri and hermaphroditic bay scallop, Argopecten irradians were investigated in this study. Spermatogenesis in C. farreri has different developmental stages: spermatogonia, primary spermatocyte, second spermatocyte, spermatid and spermatozoon. A large number of same developmental stage spermatic cells converge at a definite area of the testis. Premeiotic, previtellogenic and vitellogenic oocytes can be found during oogenesis in C. farreri , where oocyte distribution is obviously irregular. The A. irradians gonad consists of two different parts in one individual: one part functions as testis, the other as ovary. Between these two parts is a special appearance area, where a large number of spermatic cells are bound with two layers of acellular substance with many oocytes in it.展开更多
The red palm weevil Rhynchophorusferrugineus is the most important insect pest for the date palm trees in the Middle East and Gulf states. Zinc sulfate （ZnSOa＇H20） was toxicologically, biologically and physiologica...The red palm weevil Rhynchophorusferrugineus is the most important insect pest for the date palm trees in the Middle East and Gulf states. Zinc sulfate （ZnSOa＇H20） was toxicologically, biologically and physiologically evaluated as insect development disruptors against the RPW. LCs0 of Zinc sulfate against 10 days old larvae was 0.566%, 3% concentration inhibited the larvae from feeding. LCs0 concentration of zinc sulfate solution was capable to disrupting growth, development and reproduction of R. ferrugineus. Growth and development disruptions are resulted from larval feeding on the treated diet that causing percentage of mortality rate, retardation in larval and pupal duration, percentage of pupation, adults emergence, reduction in deposited eggs that laid by the resulting adults and in the egg fertility. The study further reveals that Zinc sulfate effects on histological structure of epithelial cells of the larval midgut including separation and elongation of their cells, rupture in the peritrophic membrane and in some microvilli and some degeneration of the surrounding muscles. Histological changes also was observed on the adults ovary, in this way, disrupt female gamete production through their action on the accumulation of yolk granules （vitellogenesis） and follicular epithelial cells. Disruption of male gamete production was detected by disorganized of testicular cysts and depopulation of these cysts in addition to degeneration in germ cells. Zinc sulfate may be used among other control methods by injection into the tree trunk or as fertilizer around the tree roots which in turn may have an indirect effect for controlling the RPW.展开更多
Ecological variables play a significant role in determining the diversity and distribution of any living organism on earth. Lichens are not exceptional and are quite sensitive in comparison to other organisms; hence t...Ecological variables play a significant role in determining the diversity and distribution of any living organism on earth. Lichens are not exceptional and are quite sensitive in comparison to other organisms; hence the present study focuses on the impact of ecological variables on the diversity and distribution of epiphytic macrolichens colonizing Quercus leucotrichophora across eight different sites(50 m × 50 m) in Thal Ke Dhar forest, Kumaun Himalaya, Uttarakhand, India. For sampling of macrolichens, 200 trees(25 trees from each site) of Q.leucotrichophora were selected from each site and five quadrats of 5 cm × 10 cm(1000 quadrats in totality) were drawn at the tree trunk. From all the sampled trees, a total of 54 species of epiphytic macrolichens belonging to 18 genera and five families were recorded. Various ecological variables, namely altitude, aspect, slope, diameter at breast height(DBH), and lopping percent(partial cutting of the twigs as disturbance), were also analyzed to investigate their influence on macrolichen species composition and distribution pattern in the study area. For the determination of relationships between these variables, statistical analysis, namely Pearson's Correlation Coefficient, Polynomial regression analysis and Principal Component Analysis(PCA)were performed. Out of all variables, lopping was significantly correlated to species richness of epiphytic macrolichens(0.712~*, p<0.05) and it was confirmed by Pearson's Correlation Coefficient.Despite of having high anthropogenic pressure or impact through lopping, the maximum number of macrolichen species was recorded at elevation 2267 meter above sea level(m asl). The present study revealed that besides other ecological variables,lopping practices can act as a key parameter incontrolling the diversity and distribution not only of epiphytic macrolichens but also of other life forms such as bryophytes, pteridophytes, insects, birds etc.and can be either negatively or positively correlated.展开更多
文摘Morphology of the male reproductive system, chromosome behaviors during meiosis and spem tail structures in Homoptera and Heteroptera are compared in this paper. The sheathed testis is found in Fulgoroidea and Heteroptera, and unsheathed testis occurs in Cicadoidea, Cicadelloidea, Cercopoidea, Membracoidea, Psyloidea, Aphidoidea, Aleyrodoidea and Coccoidea. The testis also can be divide into three types by the shape of testicular follicles. The sphere-shaped type is found in Cicadoidea, Cicadelloidea, Cercopoidea, Membracoidea, Aphidoidea and Aleyrodoidea, the tube-shaped type observed in Fulgoroidea, Psyloidea and Coccoidea, and the lamella-shaped type represented by Heteroptera. It is suggested the unsheathed testis may be the primitive type in Homoptera. Meiosis can be divided into 6 type at least, i.e. 1） Cicadoid type; 2） Fulgoroid type; 3） Psyloid type; 4） Aphidoid type; 5） Aleyrodoid type; and 6） Coccoid type. At least four groups exhibit a diffuse stage during meiosis prophase l, they are Psyloidea, Fulgoroidea, Coccoidea and Heteroptera. Sperm tail structures are similar to those reported from other insects with a typical 9＋9＋2 axoneme except that in Aleyrodoidea and Coccoidea whose sperm tail is degenerated.
文摘Ontogeny and metamorphic. development of female reproductive organs in Ephedra sinica Stapf were surveyed. At the end of April, female cones began to initialize from the vegetative buds. Pollination occurred in mid-May and seeds matured at the beginning of July. The ontogenetic pattern of female reproductive organs of E. sin ca is basically similar to that of E. distachya L. The foliar nature of the outer envelope of the ovule in Ephedra is corroborated. Reduction of ovule number as a tendency of speciation in the genus is substantiated by the occurrence of tri-ovulate cones coupled with comprehensive characters of the genus. The metamorphic patterns as well as the leaf nature of the outer envelope indicate that female cones of Ephedra are compound while the female reproductive units of the ovulate cone have been reduced from secondary reproductive shoots similar to those of cordaites by phylogenetic transformation, fusion and reduction. Each fertile bract together with its axillary female reproductive unit composed the Bract Scale and Seed Scale Complex of Ephedra.
基金Supported by International Science and Technology Cooperation Project of China(2012DFA31120)Special Fund for Agro-scientific Research in the Public Interest(201303094)National Key Technology Research and Development Program(2012BAD14B15)~~
文摘[Objective] The behavior of eating, drinking, defecating and peeing of 1 500 pigs in a large-scale microbial fermentation bed-equipped piggery was observed. We hoped to find some simple indicators that could reflect the health status of swinery and to provide experience for the swinery performance management in large-scale microbial fermentation bed-equipped piggery. [Method] The body weight （BW）, daily BW gain, feed intake and other indicators of different-day-old pigs were recorded in details. Based on the recorded data, the models between BW, BW gain, average daily feed intake and feed/gain ratio and growth days （d） were established. In addition, the incidences of pox-like macula （dermatitis）, diarrhea （gastrointestinal disease）, cough （respiratory disease）, stiff pig （malnutrition）, conjunctivitis （eye disease） and foot inflection （trauma） among fattening pigs were also investigated. [Result] The BW range, average BW, daily BW gain, breeding days, daily feed intake range, average daily feed intake, staged feed intake, accumulated feed intake, feed/gain ratio and accumulated feed/gain ratio of different-day-old pigs were studied, respectively. Four dynamic models were established for the growth of pigs： （1） the BW （y）-age （x） mod- el： y=0.758 9x-19.883 （3=0.993 7）; （2） the BW gain （y）-age （x） model： y=1.039 5x05051 （F=0.885 4）; （3） the average daily feed intake （y）-age （x） model： y=0.023 5x-0.334 3 （F=0.991 7）; （4） the feed/gain ratio （y）-age （x） model： y=0.022x＋0.427 8 （P=0.988 5）. Based on these models, the corresponding theoretical growth value of pigs at different growth stage could be predicted. The main diseases occurred among the swinery in the large-scale microbial fermentation bed piggery included pox-like macula （dermatitis）, diarrhea （gastrointestinal disease）, cough （respiratory disease）, stiff pig （mal- nutrition）, conjunctivitis （eye disease） and foot inflection （trauma）. The deadly infec- tious diseases had been not found among the pigs. [Conclusion] When the actual BW, BW gain, average daily feed intake and feed/gain ratio were all lower than the theoretical values predicted by the models, the management should be enhanced. The average daily feed intake of 60 to 65-day-old pigs was lower than the theoretic value, indicating that the pigs could not adapt nicely to the fermentation bed at the very early stage. When the pigs grew up to 70 to 75 d old, the average daily feed intake was higher than the theoretical value, indicating that the pigs had adapted to the fermentation bed. In particularly, average daily feed intake of 75-day-old pigs was higher than the theoretical value by 21%. It was suggested the fermentation bed was conducive to the growth of pigs. Considering the occurrence of diseases among pigs, the overall incidence was relatively low. The incidence of each disease was all lower than 10% with little difficulty in treating. If the management of mattress was strength- ened, such as paying attention to feeding and keeping water clean, many diseases could heal by themselves.
文摘Neural stem cells （NSCs） constitute the cellular basis for embryonic brain development and neurogenesis. The process is regulated by NSC niche including neighbor cells such as vascular and glial cells. Since both vascular and glial cells secrete vascular endothelial growth factor （VEGF） and basic fibroblast growth factor （bFGF）, we assessed the effect of VEGF and bFGF on NSC proliferation using nearly homogeneous NSCs that were differentiated from mouse embryonic stem cells. VEGF alone did not have any significant effect. When bFGF was added, however, VEGF stimulated NSC proliferation in a dose-dependent manner, and this stimulation was inhibited by ZM323881, a VEGF receptor （Flk-1）- specific inhibitor. Interestingly, ZM323881 also inhibited cell proliferation in the absence of exogenous VEGF, suggesting that VEGF autocrine plays a role in the proliferation of NSCs. The stimulatory effect of VEGF on NSC proliferation depends on bFGF, which is likely due to the fact that expression of Flk-1 was upregulated by bFGF via phosphorylation of ERK1/2. Collectively, this study may provide insight into the mechanisms by which microenvironmental niche signals regulate NSCs.
文摘In the past decades, a lot of advances in understanding the biochemistry and physiology of the pineal gland have been made. There is evidence that it interacts with many endocrine as well as non-endocrine tissues to influence their metabolic activity modulating many organs and functions. Melatonin is secreted by the pineal gland in the brain and plays an important role in regulating the neuroendocrine system. This hormone is one of the major role players in the regulation of the circadian sleep-wake cycle. It is normally released from the pineal gland during the night in response to environmental changes in light. Studies have shown that melatonin plays a role in the regulation of many reproductive processes such as puberty, gonadal function, and pregnancy. Beside these, melatonin has been shown to be able to directly neutralize a number of free radicals and reactive oxygen and nitrogen species. The main objective of this review is to provide comprehensive information about the new developments in melatonin research regarding its role in reproduction. A review of international scientific literature was done and a question-and-answer format was used in an attempt to convey comprehensive information in a simple manner. This review discusses evidence currently available relating to the effect of melatonin on reproductive processes. It deliberates the mechanism of action of melatonin, its effect on puberty, testicular and ovafunction, pregnancy, and oxidative stress. A growing body of scientific evidence is suggesting that melatonin plays an important role in reproductive function. It is therefore imperative to highlight the beneficial effects of this hormone in improving the reproductive processes.
文摘Fruitlet abscission （cherelle wilt） is a major factor contributing to lower productivity of cacao plantation in Indonesia. An attempt was made to reduce such cherelle wilt by spraying plant growth retardants （PGRs） on cacao trees at about 10 weeks before flowering session. The treatment was repeated every three weeks. Both the flowering initiation time and the number of flowers on the treated trees were improved significantly. With the most effective composition, flowers were initiated at 24 days after spraying （DAS）, where as the flowering initiation was 11-day later in the controls. At the 35 DAS, the chlorocholine chloride （CCC） 2,000 treatment induced about 20-80 folds more flowers than the controls. Extended observation was made to assess the treatment effect on the fruiting capacity. The treatments were found to improve fruiting ability by increasing the number of fruits set on the trees and shortening the time for fruit setting. At 20 weeks after the first spraying （WAS） there were on average 12.57 fruits per CCC 2,000-treated tree, as opposed to only 4.14 fruits per untreated tree. Analyses of the metabolites content in the flower cushions of the trees indicated that the reproductive growth is significantly correlated with the increased metabolites particularly the reduced sugar. Exogenous addition of sucrose to the PGR treatment gave greater improvement mainly in the fruiting. In conclusion, foliar spray of CCC induces flowering of cacao tress in the field that leads to improve the fruitlets productivity.
文摘Histological characteristics of gametogenesis of two kinds of scallops, gonochoric Chinese scallop, Chlamys farreri and hermaphroditic bay scallop, Argopecten irradians were investigated in this study. Spermatogenesis in C. farreri has different developmental stages: spermatogonia, primary spermatocyte, second spermatocyte, spermatid and spermatozoon. A large number of same developmental stage spermatic cells converge at a definite area of the testis. Premeiotic, previtellogenic and vitellogenic oocytes can be found during oogenesis in C. farreri , where oocyte distribution is obviously irregular. The A. irradians gonad consists of two different parts in one individual: one part functions as testis, the other as ovary. Between these two parts is a special appearance area, where a large number of spermatic cells are bound with two layers of acellular substance with many oocytes in it.
文摘The red palm weevil Rhynchophorusferrugineus is the most important insect pest for the date palm trees in the Middle East and Gulf states. Zinc sulfate （ZnSOa＇H20） was toxicologically, biologically and physiologically evaluated as insect development disruptors against the RPW. LCs0 of Zinc sulfate against 10 days old larvae was 0.566%, 3% concentration inhibited the larvae from feeding. LCs0 concentration of zinc sulfate solution was capable to disrupting growth, development and reproduction of R. ferrugineus. Growth and development disruptions are resulted from larval feeding on the treated diet that causing percentage of mortality rate, retardation in larval and pupal duration, percentage of pupation, adults emergence, reduction in deposited eggs that laid by the resulting adults and in the egg fertility. The study further reveals that Zinc sulfate effects on histological structure of epithelial cells of the larval midgut including separation and elongation of their cells, rupture in the peritrophic membrane and in some microvilli and some degeneration of the surrounding muscles. Histological changes also was observed on the adults ovary, in this way, disrupt female gamete production through their action on the accumulation of yolk granules （vitellogenesis） and follicular epithelial cells. Disruption of male gamete production was detected by disorganized of testicular cysts and depopulation of these cysts in addition to degeneration in germ cells. Zinc sulfate may be used among other control methods by injection into the tree trunk or as fertilizer around the tree roots which in turn may have an indirect effect for controlling the RPW.
基金Head, Department of Botany, S.S.J. Campus Kumaun University, Almora - 263601 for providing laboratory facilities and G. B. Pant National Institute of Himalayan Environment and Sustainable Development, Kosi-Katarmal, Almora263643 (GBPI/IERP/16-17/16/175) for financial assistance
文摘Ecological variables play a significant role in determining the diversity and distribution of any living organism on earth. Lichens are not exceptional and are quite sensitive in comparison to other organisms; hence the present study focuses on the impact of ecological variables on the diversity and distribution of epiphytic macrolichens colonizing Quercus leucotrichophora across eight different sites(50 m × 50 m) in Thal Ke Dhar forest, Kumaun Himalaya, Uttarakhand, India. For sampling of macrolichens, 200 trees(25 trees from each site) of Q.leucotrichophora were selected from each site and five quadrats of 5 cm × 10 cm(1000 quadrats in totality) were drawn at the tree trunk. From all the sampled trees, a total of 54 species of epiphytic macrolichens belonging to 18 genera and five families were recorded. Various ecological variables, namely altitude, aspect, slope, diameter at breast height(DBH), and lopping percent(partial cutting of the twigs as disturbance), were also analyzed to investigate their influence on macrolichen species composition and distribution pattern in the study area. For the determination of relationships between these variables, statistical analysis, namely Pearson's Correlation Coefficient, Polynomial regression analysis and Principal Component Analysis(PCA)were performed. Out of all variables, lopping was significantly correlated to species richness of epiphytic macrolichens(0.712~*, p<0.05) and it was confirmed by Pearson's Correlation Coefficient.Despite of having high anthropogenic pressure or impact through lopping, the maximum number of macrolichen species was recorded at elevation 2267 meter above sea level(m asl). The present study revealed that besides other ecological variables,lopping practices can act as a key parameter incontrolling the diversity and distribution not only of epiphytic macrolichens but also of other life forms such as bryophytes, pteridophytes, insects, birds etc.and can be either negatively or positively correlated.
