Hasil untuk "Plant ecology"

L. Vet, M. Dicke

R. Gillespie

T. Knight, J. Steets, J. Vamosi et al.

J. Chave

J. Bever, Kristi M. Westover, J. Antonovics

D. Hodáňová

D. Mclusky, M. Elliott

A. Barata, M. Malfeito-Ferreira, V. Loureiro

S. Scheiter, Liam Langan, S. Higgins

Kristin Ludewig, Heather A. Shupe, Lizeth K. Vásconez Navas et al.

Wetlands help to regulate the climate by sequestering and storing carbon from the atmosphere into their biomass and soils. Although wetlands can provide valuable ecosystem services such as carbon sequestration, there is a lack of quantifiable data for different types of wetlands. Teal-green carbon in floodplain forests and blue carbon in coastal and marine environments are the focus of this study. We use two contrasting wetland habitats and explore carbon sequestration and storage mechanisms, current evidence and data gaps, and their potential opportunities to contribute to climate change mitigation. Using a case study of hardwood floodplain forests in Germany, we find that age, structure and hydrological conditions are important factors in carbon sequestration while the evidence shows that sequestration is higher in young forests compared to old ones. Soil carbon stocks are found to be larger in the low elevated active floodplain compared to the higher elevated floodplain highlighting the importance of connectivity between the river and the floodplain. In a second case-study exploring carbon storage in Scottish saltmarshes, similar factors driving carbon storage are seen, including, position in the tidal frame, sediment supply, and sediment type. The policy landscape is used to highlight opportunities to increase the potential contribution of Scottish saltmarshes for climate change mitigation. Although data are limited and gaps exist for other greenhouse gas fluxes, overall, we argue that it is crucial to conserve all remaining riverine and coastal wetlands for their biodiversity and carbon storage function. Where possible and practical, these valuable ecosystems should be restored to increase their potential in this regard. Highlights Blue and teal-green carbon habitats can make an important contribution to carbon sequestration and storage. Blue and teal-green carbon habitats offer multiple ecosystem services in addition to carbon sequestration. Protection and restoration of blue and teal-green carbon habitats provide opportunities for improved climate change mitigation potential.

Qiujie Lu, Xiaofei Zhai, Feiyun Tu et al.

The Hainan Gymnure Neohylomys hainanensis is a small-size mammal which occurs in Hainan, China and north Vietnam. Here, we report the complete mitochondrial genome of N. hainanensis. The whole mitochondrial genome is 17,337 bp, and contains 13 protein-coding genes, 22 tRNAs, 2 rRNAs and one control region. The base composition of the N. hainanensis total mitogenome is: 33.4% A, 12.2% G, 33.1% T, and C 21.3%, with an A + T content of 66.5%. The K2P genetic distance analysis supports current taxonomy that places N. hainanensis, Hylomys suillus and Neotetracus sinensis in different genera. Phylogenetic analysis suggests that N . hainanensis is closely related to Neotetracus sinensis based on the complete mitochondrial genome sequences. The mitogenomic data will contribute to molecular phylogenetics and conservation genetics of the species.

Hsiao-Han Lin, Marta Torres, Catharine A. Adams et al.

Studying plant–microbe–soil interactions is challenging due to their high complexity and variability in natural ecosystems. While fabricated ecosystems provide opportunities to recapitulate aspects of these systems in reduced complexity and controlled environments, inoculation can be a significant source of variation. To tackle this, we evaluated how different bacterial inoculation practices and plant harvesting time points affect the reproducibility of a synthetic microbial community (SynCom) in association with the model grass Brachypodium distachyon. We tested three microbial inoculation practices, seed inoculation, transplant inoculation, and seedling inoculation, and two harvesting points, early (14-day-old plants) and late (21 days postinoculation). We grew our plants and bacterial strains in sterile devices (EcoFABs) and characterized the microbial community from root, rhizosphere, and sand using 16S ribosomal RNA gene sequencing. The results showed that inoculation practices significantly affected the rhizosphere microbial community when harvesting at an early time point but not at the late time point. As the SynCom showed a persistent association with B. distachyon at 21 days postinoculation regardless of inoculation practices, we assessed the reproducibility of each inoculation method and found that transplant inoculation showed the highest reproducibility. Moreover, plant biomass was not adversely affected by transplant inoculation treatment. We concluded that bacterial inoculation while transplanting coupled with a later harvesting time point gives the most reproducible microbial community in the EcoFAB−B. distachyon−SynCom fabricated ecosystem. We recommend this method as a standardized protocol for use with fabricated ecosystem experimental systems. [Graphic: see text] This manuscript has been authored by an author at Lawrence Berkeley National Laboratory under Contract number DE-AC02-05CH11231 with the U.S. Department of Energy. The U.S. Government retains, and the publisher, by accepting the article for publication, acknowledges, that the U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. Government purposes. This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

وحید رومی, مینا راستگو

زعفران (Crocus sativus) ‏یک گیاه چند ساله با ارزش است که به­ طور وسیعی در ایران بعنوان یک گیاه ادویه­ ای و دارویی کشت می­ شود. بیمارگرهای متعددی از جمله ویروس ­ها می­ توانند زعفران را آلوده کرده و کیفیت و کمیت محصول را کاهش دهند. بدلیل دردسترس نبودن مواد شیمیایی ضد ویروسی بصورت تجاری، تشخیص دقیق و قابل اعتماد یک جنبه حیاتی در مدیریت بیماری­ های ویروسی است. امروزه توالی ­یابی با بازده بالا (high throughput sequencing) به تکنولوژی رایج تشخیص ویروس ­های شناخته شده و نیز ویروس­ های جدید در گیاهان تبدیل شده است. در این مطالعه با استفاده از آنالیز توالی­ یابی با بازده بالا، ویروس پنهان زعفران (SaLV) و ویروس تی هسته داران (PrVT) درداده­ های ترانسکریپتوم حاصل از خامه زعفران شناسایی شد و ترادف تقریبا کامل این ویروس ­ها بدست آمد. ترادف نوکلئوتیدی SaLV 98.3 درصد یکسانی ترادف با تنها جدایه موجود در ژن بانک داشت. کمترین و بیشترین میزان یکسانی ترادف نوکلئوتیدی جدایه زعفران PrVT با تپوویروس های موجود در ژن­بانک بین 42.9 درصد (ویروس تی سیب زمینی جدایه پرو) و 76.9 درصد (جدایه GR168 ویروس تی زیتون(OlVT)) بود. در درخت تبارزایی، جدایه زعفران PrVT به همراه دو جدایه OlVT از یونان و یک جدایه PrVT در یک گروه قرار گرفتند. این تحقیق، اولین گزارش از وقوع PrVT بر روی زعفران در دنیا می باشد.

Hubert Hasenauer

Buster P. Mogonong, Jolene T. Fisher, David Furniss et al.

Rural landscapes in South Africa experience high conversion rates due to intense land use; however, the changes are site specific and depend on the socio-economic and political history of the area. Land cover change (LCC) was assessed in response to socio-economic and political factors in uThukela Municipal District, KwaZulu-Natal, using Landsat imagery from 1984 to 2014, while making comparisons to other studies in South Africa. Socio-economic/political data were used to gain insights into the observed LCC patterns. Land cover was classified using a random forest classifier, and accuracies ranging from 87% to 92% were achieved. Systematic and intensity analysis methods were used to describe patterns, rates, and transitions of LCC in Imbabazane (ILM) and Okhahlamba (OLM) local municipalities. The results showed a reduced rate of change intensity from 3.4% to 0.9% in ILM and from 3.1% to 1.1% in OLM between 1984 and 2014. Grassland was persistent, covering over 70% in both local municipalities between 1984 and 2014. Although persistent, grassland experienced respective losses of 3.7% and 14.3% in both observation periods in ILM and of 10.2% and 13.3% in OLM. During the analysis period, settlements and cropland gained actively in both local municipalities. The changes represent a degree of population, local authority, and people’s perception as influencers of land use and LCC. It is therefore argued that socio-economic and political changes can potentially influence land use and LCC; however, natural ecosystems can persist under those conditions, and this requires more research efforts. Significance: This study contributes towards a growing knowledge and understanding of land cover change studies in marginalised landscapes in South Africa. The findings enforce the notion that natural vegetation systems can be altered by human-induced land use such as expansion of settlement and commercial agricultural. We show that in recent times there has been a decline in the overall rate of land cover conversion, and a high persistence of grassland amid global change, although the quality of the vegetation needs further research. We argue that the changes observed in marginalised landscapes are potentially driven by socio-economic and political dynamics.

Antonio Morabito, Marina Allegrezza, Claudia Angiolini et al.

New Italian data on the distribution of the Annex I Habitats are reported in this contribution. Specifically, 8 new occurrences in Natura 2000 sites are presented and 49 new cells are added in the EEA 10 km × 10 km reference grid. The new data refer to the Italian administrative regions of Campania, Calabria, Marche, Piedmont, Sardinia, Sicily, Tuscany and Umbria. Relevés and figures are provided as Supplementary material respectively 1 and 2.

Germán Pérez, Sascha M. B. Krause, Paul L. E. Bodelier et al.

Cyanobacteria play a relevant role in rice soils due to their contribution to soil fertility through nitrogen (N₂) fixation and as a promising strategy to mitigate methane (CH₄) emissions from these systems. However, information is still limited regarding the mechanisms of cyanobacterial modulation of CH₄ cycling in rice soils. Here, we focused on the response of methane cycling microbial communities to inoculation with cyanobacteria in rice soils. We performed a microcosm study comprising rice soil inoculated with either of two cyanobacterial isolates (<i>Calothrix</i> sp. and <i>Nostoc</i> sp.) obtained from a rice paddy. Our results demonstrate that cyanobacterial inoculation reduced CH₄ emissions by 20 times. Yet, the effect on CH₄ cycling microbes differed for the cyanobacterial strains. Type Ia methanotrophs were stimulated by <i>Calothrix</i> sp. in the surface layer, while <i>Nostoc</i> sp. had the opposite effect. The overall <i>pmoA</i> transcripts of Type Ib methanotrophs were stimulated by <i>Nostoc</i>. Methanogens were not affected in the surface layer, while their abundance was reduced in the sub surface layer by the presence of <i>Nostoc</i> sp. Our results indicate that mitigation of methane emission from rice soils based on cyanobacterial inoculants depends on the proper pairing of cyanobacteria–methanotrophs and their respective traits.

T. R. Zapata, M. Arroyo

David Johnston-Monje, Janneth P. Gutiérrez, Luis Augusto Becerra Lopez-Lavalle

A plant’s health and productivity is influenced by its associated microbes. Although the common/core microbiome is often thought to be the most influential, significant numbers of rare or uncommon microbes (e.g., specialized endosymbionts) may also play an important role in the health and productivity of certain plants in certain environments. To help identify rare/specialized bacteria and fungi in the most important angiosperm plants, we contrasted microbiomes of the seeds, spermospheres, shoots, roots and rhizospheres of <i>Arabidopsis</i>, <i>Brachypodium</i>, maize, wheat, sugarcane, rice, tomato, coffee, common bean, cassava, soybean, switchgrass, sunflower, <i>Brachiaria</i>, barley, sorghum and pea. Plants were grown inside sealed jars on sterile sand or farm soil. Seeds and spermospheres contained some uncommon bacteria and many fungi, suggesting at least some of the rare microbiome is vertically transmitted. About 95% and 86% of fungal and bacterial diversity inside plants was uncommon; however, judging by read abundance, uncommon fungal cells are about half of the mycobiome, while uncommon bacterial cells make up less than 11% of the microbiome. Uncommon-seed-transmitted microbiomes consisted mostly of Proteobacteria, Firmicutes, Bacteriodetes, Ascomycetes and Basidiomycetes, which most heavily colonized shoots, to a lesser extent roots, and least of all, rhizospheres. Soil served as a more diverse source of rare microbes than seeds, replacing or excluding the majority of the uncommon-seed-transmitted microbiome. With the rarest microbes, their colonization pattern could either be the result of stringent biotic filtering by most plants, or uneven/stochastic inoculum distribution in seeds or soil. Several strong plant–microbe associations were observed, such as seed transmission to shoots, roots and/or rhizospheres of <i>Sarocladium zeae</i> (maize), <i>Penicillium</i> (pea and <i>Phaseolus</i>), and <i>Curvularia</i> (sugarcane), while robust bacterial colonization from cassava field soil occurred with the cyanobacteria <i>Leptolyngbya</i> into <i>Arabidopsis</i> and <i>Panicum</i> roots, and <i>Streptomyces</i> into cassava roots. Some abundant microbes such as <i>Sakaguchia</i> in rice shoots or <i>Vermispora</i> in <i>Arabidopsis</i> roots appeared in no other samples, suggesting that they were infrequent, stochastically deposited propagules from either soil or seed (impossible to know based on the available data). Future experiments with culturing and cross-inoculation of these microbes between plants may help us better understand host preferences and their role in plant productivity, perhaps leading to their use in crop microbiome engineering and enhancement of agricultural production.

Yajie Zhao, Chang Liu, Juanjuan Sui et al.

Ornamental geophytes are a group of important flowers worldwide. As perennial plants, geophytes go through several rounds of life cycle under seasonal climates. The dormant trait of underground modified organs in geophytes is critical for the process of storage, planting as well as breeding. Although the dormant physiology in geophytes is complex and largely unknown, several advancements have been achieved in this field. Here, we review the knowledge on the role of environmental factors, endogenous hormones, carbohydrates, and epigenetics in the regulation of geophytes dormancy release (GDR). We also discuss dormancy release (DR) methods and their roles in geophytes, including small molecular chemicals and wounding treatments.