Using UAV and Field Measurement Technology to Monitor the Impact of Coal Gangue Pile Temperature on Vegetation Ecological Construction

Coal gangue is an inevitable product in coal mining and processing and is the most important source of pollution in mines. Vegetation restoration of coal gangue piles must consider its special site conditions. Therefore, we conducted unmanned air vehicle (UAV) temperature monitoring, field investigation and experimental analysis on spontaneous combustion coal gangue piles in Lu’an mining area. In the vegetation construction of coal gangue piles, high-temperature stress affects plant survival. The spontaneous combustion coal gangue piles have abnormal temperature, high surface temperature and few vegetation types. The plant community species diversity index (Shannon–Wiener index, Pielou’s index and Species abundance index) is small, the plant community is single and the plant diversity is low. Spontaneous combustion of coal gangue leads to soil acidification, reducing soil water content, soil organic carbon (SOM), available nitrogen (AN), available potassium (AK) and available phosphorus (AP). These factors are single or interactive in plants and have an impact on plant survival and growth. The research results are of great significance to the vegetation restoration of spontaneous combustion coal gangue piles, ecological reconstruction and the improvement of the ecological environment of coal mine areas.

Screening of Onion (Allium cepa L.) Genotypes for Waterlogging Tolerance

Onion production is severely affected by waterlogging conditions, which are created due to heavy rainfall. Hence, the identification of waterlogging-tolerant onion genotypes is crucial for increasing onion production. In the present study, 100 distinct onion genotypes were screened for waterlogging tolerance under artificial conditions by using the phenotypic approach in the monsoon season of 2017. Based on plant survival and recovery and changes in bulb weight, we identified 19 tolerant, 27 intermediate tolerant, and 54 highly sensitive onion genotypes. The tolerant genotypes exhibited higher plant survival and better recovery and bulb size, whereas sensitive genotypes exhibited higher plant mortality, poor recovery, and small bulb size under waterlogging conditions. Furthermore, a subset of 12 contrasting genotypes was selected for field trials during monsoon seasons 2018 and 2019. Results revealed that considerable variation in the morphological, physiological, and yield characteristics were observed across the genotypes under stress conditions. Waterlogging-tolerant genotypes, namely, Acc. 1666, Acc. 1622, W-355, W-208, KH-M-2, and RGP-5, exhibited higher plant height, leaf number, leaf area, leaf length, chlorophyll content, membrane stability index (MSI), pyruvic acid, antioxidant content, and bulb yield than sensitive genotypes under stress conditions. Furthermore, the principal component analysis biplot revealed a strong association of leaf number, leaf area, chlorophyll content, MSI, and bulb yield with tolerant genotypes under stress conditions. The study indicates that the waterlogging-tolerant onion genotypes with promising stress-adaptive traits can be used in plant breeding programs for developing waterlogging-tolerant onion varieties.

Local climate and vernalization requirements explain the latitudinal patterns of flowering initiation in the crop wild relative Linum bienne

Background and Aims: Days to flowering initiation in species with large geographic distributions often correlate with latitude. Latitude reflects climatic gradients, but it is unclear if large-scale differentiation in flowering results from adaptation to local climate, and whether adaptation to local climate could constrain shifts in distribution and colonization of new environments. Methods: In its Western range in Europe, L. bienne populations were surveyed to describe latitudinal patterns of flowering initiation and determine its correlation with the local climate of populations. This was measured under standardized greenhouse conditions, with a vernalization experiment to learn if chilling advances flowering, and with a reciprocal transplant experiment at three sites along the latitudinal gradient, recording flowering at the central site and plant survival in all sites. Also, genetic differentiation of populations along the latitudinal range was studied using microsatellite markers. Key Results: Flowering initiation varied with latitude, with southern populations flowering earlier than northern populations. Latitude also predicted population response to vernalization, with chilling inducing a greater advance of flowering initiation in northern than southern populations. In general, plant survival in the reciprocal transplant experiment decreased with the geographic distance of populations to the experimental site and, at the central site, flowering initiation varied with latitude of origin. However, across experiments, the local climate of populations better predicted the differentiation in flowering initiation and vernalization response than latitude of origin. Finally, the microsatellite data revealed genetic differentiation of populations forming two groups that agree with a Mediterranean and Atlantic lineage. Conclusions: The consistent result across experiments of a latitudinal cline in flowering initiation and in the vernalization response suggests that flowering is under genetic regulation and yet dependent on particular environmental and climatic cues at local scale. However, the genetic differentiation suggests that past population history might influenced the flowering initiation patterns detected.

Diverse phylogenetic neighborhoods enhance community resistance to drought in experimental assemblages

Although the role played by phylogeny in the assembly of plant communities remains as a priority to complete the theory of species coexistence, experimental evidence is lacking. It is still unclear to what extent phylogenetic diversity is a driver or a consequence of species assembly processes. We experimentally explored how phylogenetic diversity can drive the community level responses to drought conditions in annual plant communities. We manipulated the initial phylogenetic diversity of the assemblages and the water availability in a common garden experiment with two irrigation treatments: average natural rainfall and drought, formed with annual plant species of gypsum ecosystems of Central Spain. We recorded plant survival and the numbers of flowering and fruiting plants per species in each assemblage. GLMMs were performed for the proportion of surviving, flowering, fruiting plants per species and for total proportion of surviving species and plants per pot. In water limited conditions, high phylogenetic diversity favored species coexistence over time with higher plant survival and more flowering and fruiting plants per species and more species and plants surviving per pot. Our results agree with the existence of niche complementarity and the convergence of water economy strategies as major mechanisms for promoting species coexistence in plant assemblages in semiarid Mediterranean habitats. Our findings point to high phylogenetic diversity among neighboring plants as a plausible feature underpinning the coexistence of species, because the success of each species in terms of surviving and producing offspring in drought conditions was greater when the initial phylogenetic diversity was higher. Our study is a step forward to understand how phylogenetic relatedness is connected to the mechanisms determining the maintenance of biodiversity.

The transcription factor AtHB23 modulates starch turnover for root development and plant survival under salinity

AtHB23 is a homeodomain-leucine zipper I transcription factor, previously characterized as a modulator of lateral root initiation and higher-order roots development. The role of this gene in response to salinity stress was completely unknown. To elucidate the role of AtHB23 in response to salinity stress, we combined histochemical β-glucuronidase (GUS) analysis, root phenotyping, starch staining, optic and electronic transmission microscopy, expression studies by RT-qPCR, and transcriptome analysis of silenced, overexpressor, and crossed plants. We revealed that the expression pattern of AtHB23 is regulated by NaCl in the main and lateral roots, affecting the root phenotype. A severe reduction in primary root length, a significant increment in the initiation of lateral roots, and a low survival rate in salinity conditions were observed in AtHB23-silenced plants, whereas AtHB23 overexpressors showed the opposite phenotype. These developmental defects were explained by the degradation of starch granules and an alteration in starch metabolism. The AtHB23-target gene LAX3 is repressed in the tip of the main root and affected by NaCl. We conclude that AtHB23 is vital for plant survival and adaptation to salt stress conditions, and its function is related to the gravitropic response mediated by starch granule turnover, involving the auxin carrier LAX3.

Twenty Years of Providing Free Plants in An Urban New Zealand Setting: What Affects Community Participation and Planting Success?

<p>An urban greening programme in Wellington, New Zealand providing free plants to city residents was evaluated with the following objectives: 1. To assess the levels of plant survival after five, ten, and fifteen years and determine factors contributing to observed survival; 2. To investigate factors influencing participation in the programme; 3. To quantify the some of the socioeconomic factors relating to programme participants and environmental factors relating to sites. Data were collected from a combination of council records, site surveys and postal questionnaire surveys. The study found that plant survival was generally poor, but was mainly influenced by indigeneity of the plants. Contrary to many theories of exotic invasiveness, New Zealand native plants were 4.3 times more likely to survive than exotic plants. Site based effects were not found to influence survival significantly; nor were specific plant traits, or year of planting. A small sample of these sites was matched to questionnaire responses and it was found that length of residence by programme participants increased the performance of the best model indigeneity, indicating that increasing length of residence was a predictor of better survival of plantings. The questionnaire respondents included both those who had participated in the programme and those who had not. The sample population, however, was quite distinct from the general population of the region, being older, wealthier, having higher levels of education, and twice as likely to own their own home. As suggested by previous research looking at the effects of socioeconomic factors on urban forestry or urban greening participation was shown in this study to be mainly affected by the age of the respondent, which increased the odds of participation by 200% between the youngest and oldest age groups. This socioeconomic model was improved when two factors were included: the number of trees outside their property, and, horticultural knowledge of the participant. This indicates that participants might be more motivated by personal interest in horticulture, than in improving environmental conditions.</p>

Twenty Years of Providing Free Plants in An Urban New Zealand Setting: What Affects Community Participation and Planting Success?

<p>An urban greening programme in Wellington, New Zealand providing free plants to city residents was evaluated with the following objectives: 1. To assess the levels of plant survival after five, ten, and fifteen years and determine factors contributing to observed survival; 2. To investigate factors influencing participation in the programme; 3. To quantify the some of the socioeconomic factors relating to programme participants and environmental factors relating to sites. Data were collected from a combination of council records, site surveys and postal questionnaire surveys. The study found that plant survival was generally poor, but was mainly influenced by indigeneity of the plants. Contrary to many theories of exotic invasiveness, New Zealand native plants were 4.3 times more likely to survive than exotic plants. Site based effects were not found to influence survival significantly; nor were specific plant traits, or year of planting. A small sample of these sites was matched to questionnaire responses and it was found that length of residence by programme participants increased the performance of the best model indigeneity, indicating that increasing length of residence was a predictor of better survival of plantings. The questionnaire respondents included both those who had participated in the programme and those who had not. The sample population, however, was quite distinct from the general population of the region, being older, wealthier, having higher levels of education, and twice as likely to own their own home. As suggested by previous research looking at the effects of socioeconomic factors on urban forestry or urban greening participation was shown in this study to be mainly affected by the age of the respondent, which increased the odds of participation by 200% between the youngest and oldest age groups. This socioeconomic model was improved when two factors were included: the number of trees outside their property, and, horticultural knowledge of the participant. This indicates that participants might be more motivated by personal interest in horticulture, than in improving environmental conditions.</p>

Twenty Years of Providing Free Plants in An Urban New Zealand Setting: What Affects Community Participation and Planting Success?

<p>An urban greening programme in Wellington, New Zealand providing free plants to city residents was evaluated with the following objectives: 1. To assess the levels of plant survival after five, ten, and fifteen years and determine factors contributing to observed survival; 2. To investigate factors influencing participation in the programme; 3. To quantify the some of the socioeconomic factors relating to programme participants and environmental factors relating to sites. Data were collected from a combination of council records, site surveys and postal questionnaire surveys. The study found that plant survival was generally poor, but was mainly influenced by indigeneity of the plants. Contrary to many theories of exotic invasiveness, New Zealand native plants were 4.3 times more likely to survive than exotic plants. Site based effects were not found to influence survival significantly; nor were specific plant traits, or year of planting. A small sample of these sites was matched to questionnaire responses and it was found that length of residence by programme participants increased the performance of the best model indigeneity, indicating that increasing length of residence was a predictor of better survival of plantings. The questionnaire respondents included both those who had participated in the programme and those who had not. The sample population, however, was quite distinct from the general population of the region, being older, wealthier, having higher levels of education, and twice as likely to own their own home. As suggested by previous research looking at the effects of socioeconomic factors on urban forestry or urban greening participation was shown in this study to be mainly affected by the age of the respondent, which increased the odds of participation by 200% between the youngest and oldest age groups. This socioeconomic model was improved when two factors were included: the number of trees outside their property, and, horticultural knowledge of the participant. This indicates that participants might be more motivated by personal interest in horticulture, than in improving environmental conditions.</p>

Twenty Years of Providing Free Plants in An Urban New Zealand Setting: What Affects Community Participation and Planting Success?

<p>An urban greening programme in Wellington, New Zealand providing free plants to city residents was evaluated with the following objectives: 1. To assess the levels of plant survival after five, ten, and fifteen years and determine factors contributing to observed survival; 2. To investigate factors influencing participation in the programme; 3. To quantify the some of the socioeconomic factors relating to programme participants and environmental factors relating to sites. Data were collected from a combination of council records, site surveys and postal questionnaire surveys. The study found that plant survival was generally poor, but was mainly influenced by indigeneity of the plants. Contrary to many theories of exotic invasiveness, New Zealand native plants were 4.3 times more likely to survive than exotic plants. Site based effects were not found to influence survival significantly; nor were specific plant traits, or year of planting. A small sample of these sites was matched to questionnaire responses and it was found that length of residence by programme participants increased the performance of the best model indigeneity, indicating that increasing length of residence was a predictor of better survival of plantings. The questionnaire respondents included both those who had participated in the programme and those who had not. The sample population, however, was quite distinct from the general population of the region, being older, wealthier, having higher levels of education, and twice as likely to own their own home. As suggested by previous research looking at the effects of socioeconomic factors on urban forestry or urban greening participation was shown in this study to be mainly affected by the age of the respondent, which increased the odds of participation by 200% between the youngest and oldest age groups. This socioeconomic model was improved when two factors were included: the number of trees outside their property, and, horticultural knowledge of the participant. This indicates that participants might be more motivated by personal interest in horticulture, than in improving environmental conditions.</p>