1,843 research outputs found

    Remote Sensing Application to Grassland Monitoring

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    Application of remote sensing to the management of grassland resources, the role this plays in developing sustainable grassland farming systems and opportunities for further development are outlined. Use of remote sensing technologies in grassland monitoring has a history of more than 30 years. Both fine- and coarse-grained remote sensing techniques are used to monitor and study grasslands. Fine-grained techniques are used to study landscape scale processes through the use of sensors providing spatial resolution of a few meters, whereas coarse-grained techniques are used to study catchment scale areas, and even entire biomes, using satellite-based sensors with a spatial resolution of kilometers. Remote sensing information is obtained from aerial photography, radar systems, video systems, and satellite-based sensors including the Landsat satellites’ Multispectral Scanner (MSS) and Thematic mapper (TM) and the National Oceanic and Atmospheric Administration (NOAA) polar orbiters’ Advanced Very High Resolution Radiometer (AVHRR). Various normalized difference vegetation indices (NDVI) have been developed and used extensively with data from the Landsat sensors (MSS and TM) and NOAA’s AVHRR. The NDVI has been used for grassland classification and inventory, monitoring grassland-use change, determination of site productivity and herbivore carrying capacity, water and soil conservation, integrated management of grassland pests, and suitability for recreational use and wild life protection. Special techniques have also been developed for monitoring where fires occur on grasslands. To date the remote sensing techniques have become a powerful tool for scientists, farmers and policy makers to study and manage grassland resources. World demand for sustainable development of grasslands will increase the reliance on remote sensing as a tool in grassland management. However, the adaptation of existing remote sensing technology in grassland management will require more scientists and technicians to be trained in both remote sensing and grassland science. Additional training programs targeting scientists in developing countries will be needed. System approaches will be required that lead to better understanding of the interfacing of ground and remote sensing data sets. There is also a need for research on low cost, high resolution systems to be flown from aircraft and helicopters using narrow filters for assessing the condition of grassland health

    Comprehensive Evaluation of Endophytic Fungi and Rhizosphere Soil Fungi on the Growth of \u3cem\u3eAchnatherum inebrians\u3c/em\u3e

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    This study was conducted to clarify the effect of endophytic fungi and rhizosphere soil fungi on the growth of Achnatherum inebrians. In this study, the seeds of A. inebrians with endophyte-infected (EI) and endophyte-free (EF) were used as materials. Eight fungi isolated from rhizosphere soil were inoculated through germination and greenhouse pot experiment. The results showed that the endophytes, rhizosphere soil fungi and their combined effect all had significant effect on the seed germination and plant growth of A. inebrians, and the affected factors varied with the tested materials and strains. Through comprehensive evaluation of principal component analysis and subordinate function, it was found that the overall growth performance of EI was better than that of EF plants, and the strains that inhibited the growth of A. inebrians were Cladosporium. sp2 and Fusarium sp1

    Chaos control in random Boolean networks by reducing mean damage percolation rate

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    Chaos control in Random Boolean networks is implemented by freezing part of the network to drive it from chaotic to ordered phase. However, controlled nodes are only viewed as passive blocks to prevent perturbation spread. This paper proposes a new control method in which controlled nodes can exert an active impact on the network. Controlled nodes and frozen values are deliberately selected according to the information of connection and Boolean functions. Simulation results show that the number of nodes needed to achieve control is largely reduced compared to previous method. Theoretical analysis is also given to estimate the least fraction of nodes needed to achieve control.Comment: 10 pages, 2 figure

    Soil Microbial Community: Understanding the Belowground Network for Sustainable Grassland Management

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    In addition to the use of conventional methodologies in soil microbial research, molecular techniques are now being applied to gain insights into the soil microbial community; Plant diversity can exert impacts on soil microbial diversity (through root activities and plant litter etc.), but may in itself be significantly altered by soil properties; Soil microbial diversity largely determines the stability of soil ecosystems under biotic and abiotic perturbations. Management of soil microbial diversity can only be achieved through better understanding their structures and functions

    Soil Microbial Community: Understanding the Belowground Network for Sustainable Grassland Management

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    Key points 1. In addition to the use of conventional methodologies in soil microbial research, molecular techniques are now being applied to gain insights into the soil microbial community; 2. Plant diversity can exert impacts on soil microbial diversity (through root activities and plant litter etc.), but may in itself be significantly altered by soil properties; 3. Soil microbial diversity largely determines the stability of soil ecosystems under biotic and abiotic perturbations. 4. Management of soil microbial diversity can only be achieved through better understanding their structures and functions

    Isolation and molecular characterization of RcSERK1: A Rosa canina gene transcriptionally induced during initiation of protocorm-like bodies

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    A somatic embryogensis receptor-like kinase (SERK) gene was isolated from protocorm-like bodies (PLBs) of Rosa canina by a rapid amplification of cDNA ends (RACE) approach and was designated as RcSERK1. The RcSERK1 encodes a protein of 626 amino acid residues with a calculated molecular mass of 68.79 kDa and theoretical isoelectric point of 5.65. The amino acid sequence of RcSERK1 shares all the characteristic features of a SERK protein, including the signal peptide (SP), the leucine zipper (LZ), the five leucine-rich repeats (LRRs), the pro-rich domain containing the so-called Ser-Pro- Pro (SPP) motif, the transmembrane domain (TM), the kinase domain and the C-terminal domain. The transcripts of RcSERK1 were more enriched in PLBs than in rhizoids and callus, but not detected in leaflets (incubated under dark and before producing callus) and the regenerated shoots. Subcellular localization indicated that the fluorescence of RcSERK1-GFP was recorded in the plasma membrane. We argue that RcSERK1 is a Leu-rich repeat receptor-like kinase (LRR-RLK) and plasma  membrane localization protein.Keywords: somatic embryogensis receptor-like kinase (SERK)1, protocorm-like bodies (PLBs), Rosa canina, RACE, RcSERK1
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