Arbuscular mycorrhizal colonization of vascular plants from the Yungas forests, Argentina

In Argentina, the Yungas forests are among the ecosystems most affected by human activity, with loss of biodiversity. To assess the mycorrhizal status in these ecosystems, the roots of 41 native plant species belonging to 25 families were collected throughout the year from two sites of the Yungas forests. Roots were washed and stained to study the presence of arbuscular mycorrhizas (AM). Morphological types of arbuscular mycorrhizas (Arum and Paris-type) and colonization patterns were identified and photographed. All plants presented AM colonization. The AM colonization patterns varied from single intracellular aseptate hyphae, coils, appresoria, to vesicles and/or arbuscules. Among the species studied, the Paris-type colonization showed to be dominant. Results confirmed that AM hosts are predominant in the Yungas of South American forests.     

Arbuscular mycorrhizal symbioses in a cut-and-carry forage production system of legume tree Gliricidia sepium and fodder grass Dichanthium aristatum

Arbuscular mycorrhizal (AM) symbioses may alter the competitive abilities of plant species and facilitate positive interactions such as nutrient transfer between plants. They are therefore particularly interesting components in agroforestry systems. We studied spatial variation of AM colonisation on a cut-and-carry fodder production site (agroforestry plot) of the legume tree Gliricidia sepium and the fodder grass Dichanthium aristatum. Roots of the two plant species were sampled under the tree canopies and on the adjacent grass plot at 1 and 3.5 m from the first tree row where G. sepium roots also occur. Roots of D. aristatum were also sampled on a nearby grass monocrop. Colonisation of arbuscules, vesicles and hyphae in root samples was visually determined, and AM fungal species were identified by DNA sequencing. Colonisation and frequency of types of AM formations varied statistically significantly between the species and sampling points. Arbuscular colonisation in G. sepium roots was higher under the tree canopies than on the adjacent grass plot. Soil nutrient content, particularly P and N, and interspecies competition are the most probable explanations for the observed variation in AM colonisation. Both arbuscular colonisation and arbuscule:vesicle ratio in D. aristatum roots was lower on the D. aristatum monocrop than on the agroforestry plot under or near the tree canopies. Intercropping could stimulate AM symbiosis in D. aristatum. Both plant species formed symbiosis with Rhizophagus intraradices, indicating potential for interplant N transfer via common mycelial networks of AM-forming fungi.     

Biodiversity of Arbuscular Mycorrhizal (AM) fungi in mangroves of Goa in West India

Seventeen mangrove species of eight families at seven riverine and fringe habitats in Goa West India were surveyed for Arbuscular Mycorrhizal (AM) fungal diversity. Sixteen species were found to be mycorrhizal and one species showed no AM fungal colonization. AM root colonization was recorded at all seven sites and ranged from 6%-77%. Maximum root colonization was recorded in Excoecaria agallocha (77%) and minimum colonization in Avicennia marina (6%). Paris-type colonization was predominant at all sites. Auxiliary cells were recorded in roots of Acanthus ilicifolius, Ceriops tagal and Sonneretia alba. AM fungal root colonization and spore density varied by plant species and site. Site average spore density ranged from 1.84 spores·g-1 to 0.54 spores·g-1 of soil. In total, 28 AM fungal species of five genera, viz. Glomus, Acaulospora, Scutellospora, Gigaspora and Entrophospora, were recovered. Glomus was the dominant genus, three species of which were sporocarpic forms. Maximum site species richness (SR) ranged from 16 to 5. Species richness was maximum in A. ilicifolius where seven species of three genera were recovered. Based on relative abundance (RA) and isolation frequency (IF), two common species, viz. G. intraradices and A. laevis, were recovered from all seven sites.     

Arbuscular mycorrhizas and performance of Polylepis australis trees in relation to livestock density

Polylepis australis trees endemic to Argentina dominate the canopy of subtropical high altitude forests. Here, livestock rearing is the main economic activity and is suspect of the low performance of P. australis trees through direct and indirect effects which could include the reduction in arbuscular mycorrhizal fungi (AMF) and their benefit to trees. To elucidate the role of AMF, we compare plant performance indicators, arbuscular mycorrhizal (AM) colonization and AMF communities in 20 trees distributed in two areas of central Argentina which differed in livestock grazing intensity. The area with high livestock density presented more soil degradation and trees with a lower overall plant performance than the area with reduced livestock density. The AM colonization values of P. australis were considerably higher than reported for other tree species and the area with high livestock density had a lower proportion of arbuscules and higher proportion of hyphae, while vesicles and AM colonization – all structure considered together – did not differ between areas. Overall AMF spore number and of most species when considered separately was significantly higher in the area with high livestock density, suggesting a high tolerance and adaptation of AMF to livestock. We conclude that a reduction in livestock improves the performance of P. australis, that this improvement could be mediated by an increase in the proportion of arbuscules, but there does not appear to be any limitation in AM colonization or AMF spore number which could otherwise be limiting forest restoration.     

Coinoculation of bioinoculants improve <Emphasis Type="Italic">Acacia auriculiformis</Emphasis> seedling growth and quality in a tropical Alfisol soil

We conducted a study to find out if arbuscular mycorrhizal (AM) fungi (Acaulospora scrobiculata, Scutellospora calospora) and phosphate solubilizing bacteria (PSB, Paenibacillus polymyxa) inoculation either individually or in combinations can improve Acacia auriculiformis seedling growth, uptake of nutrients and quality in a phosphorus deficient tropical Alfisol. The seedlings were assessed for various growth and nutrient uptake parameters after 60 days of treatment. Inoculation with P. polymyxa stimulated mycorrhizal formation. Seedling height, stem girth, taproot length, number of leaves and leaf area, plant dry matter production, nodulation, and nodular dry weight were significantly higher for seedlings that were either dual inoculated or triple inoculated compared to individual inoculation of AM fungi or PSB, and uninoculated seedlings. Dual and triple application of AM fungi and PSB also significantly improved the nutrient contents of shoots and roots and nutrient uptake efficiencies. The calculated seedling quality indexes of the AM fungi and PSB inoculated seedling were 25–208% higher than uninoculated seedlings. These findings show that A. auriculiformis seedlings when dual inoculated or triple inoculated performed better than seedlings inoculated with the microbes individually and compared with uninoculated control seedlings. We conclude that bioinoculation is important for the production of high-quality A. auriculiformis seedlings in tree nurseries for planting in nutrient deficient soils.     

Tree species as hosts for arbuscular mycorrhizal and dark septate endophyte fungi

A survey of 35 tree species(belonging to 28 genera in 19 families) in Aliyar,South India was carried out to ascertain their arbuscular mycorrhizal(AM) and dark septate endophyte(DSE) fungal status.All the tree species examined had AM association.AM and DSE colonization is reported for the first time in 20 and 14 species respectively.Cooccurrence of AM and DSE was observed in 14(40%) tree species.The extent of DSE colonization was inversely related to the extent of AM fungal colonization.Six tree species had Arum-type,18 had intermediatetype and 11 had typical Paris-type AM morphology.AM fungal spore morphotypes belonging to 11 species in two genera were isolated from the rhizosphere soil.AM fungal spore numbers were not related to the extent of AM colonization and Glomus dominated spore diversity.AM association individually and along with DSE were found respectively in the 63% and 44% of the economically important tree species.The occurrence of AM and DSE fungal association in economically important indigenous tree species indicates the possibility of exploiting this association in future conservation programmes of these species.     

Aeroponic production of Acacia mangium saplings inoculated with AM fungi for reforestation in the tropics

Aeroponics, a soilless plant culture method, was used to produce Acacia mangium saplings associated with arbuscular mycorrhiza (AM) fungi. A. mangium seedlings were first grown in multipots and inoculated with Endorize, a commercial AM fungal inoculum. They were then, either transferred to aeroponic systems or to soil. Aeroponics was found to be a better system than soil, allowing the production of tree saplings twice as high as those grown in soil. Moreover, compared to plants grown in soil, aeroponically grown saplings inoculated with AM fungal inoculum exhibited significantly different rates of mycorrhization, resulting in an increase in phosphorus and chlorophyll in plant tissues. Our results suggest that the aeroponic system is an innovative and appropriate technology which has the potential to produce in large quantities, tree saplings associated with soil micro-organisms, such as AM fungi, for reforestation of degraded land in the humid tropics.     

Diversity of arbuscular mycorrhizal fungi in <Emphasis Type="Italic">Tectona grandis</Emphasis> Linn.f. plantations and their effects on growth of micropropagated plantlets

Regeneration of stands of valuable tropical hardwood tree species for sustainable harvest requires production of seedlings with high probabilities of survival. One way to enhance the vigor of plants for outplanting is pre-colonization of roots by arbuscular mycorrhizal (AM) fungi. We pursued the strategy that the most promising AM fungus candidates for inoculation would be those associated with the tree of interest in the field. AM fungus communities were assessed in five plantations of Tectona grandis Linn.f. A total of 18 AM fungal morphotypes were found, representing four families: Glomeraceae (49.6%), Acaulosporaceae (24.9%), Claroideoglomeraceae (20.8%), and Gigasporaceae (4.8%). AM fungus spore density was negatively correlated with soil organic carbon. Some of these AM fungi, plus Rhizophagus irregularis, were established in pot culture and in vitro with transformed carrot roots, and subsequently used to inoculate micropropagated plantlets of T. grandis. Tectona grandis plantlets inoculated in vitro were successfully colonized by all AM fungi studied. Plants inoculated with Funneliformis mosseae were taller than uninoculated plants. Tectona grandis plantlets inoculated with the AM fungus Claroideoglomus etunicatum PBT03 were taller than uninoculated controls in ex vitro experiments. This study provides early insight for the targeted use of the AM symbiosis in production of important tree species in future greenhouse studies and reforestation.     

Arbuscular mycorrhizae and ectomycorrhizae in native tree legumes in Uruguay

The level of colonization by ectomycorrhizae (ECM) and arbuscular endomycorrhizae (AM) of 23 species of native trees and shrub legumes was studied. Root samples were obtained from different regions of Uruguay. Colonization level was determined by observing AM fungal structures (hyphae, arbuscules, vesicules) in stained root segments. The number and morphological type of spores were determined in 100 g of rhizosphere soil. Ectomycorrhizal colonization was evaluated by direct and microscopic observation of root tips. All species had a high level of AM colonization. In Papilionoideae colonization varied between 62% and 78%, in the Mimosoideae between 18% and 69% and in the Caesalpinioideae the variation was larger (6–74%). These results show a significant presence of fungi that form arbuscular mycorrhizae in our soils. The number of spores forming AM in rhizosphere soil (280–l.620 spores/100 g of dry soil) was also highly relative to references for other leguminous trees. Spores were grouped in three principal morphological types Acaulospora, Glomus and Sclerocystis. Presence of ECM fungi was evident only when observed under the microscope. 26% of the plant species exhibited this type of mycorrhizae, reaching a maximal value of 36% in Mimosoideae. Only six plant species exhibited both types of mycorrhizae. Dual colonization could help in the colonization of poor soils and for their use in agroforestry systems.     

Effects of two Glomus species on the growth and physiological performance of Sophora davidii seedlings under water stress

Sophora davidii is an important leguminous scrub that is widely used for revegetation in the semiarid Loess Plateau and other arid valley areas of China, where it usually suffers drought stress. This study investigated the effects of arbuscular mycorrhizal (AM) fungi (Glomus mosseae and Glomus constrictum) and water stress on the growth and physiological performance of S. davidii seedlings under greenhouse pot conditions. Two soil water availability treatments (well-watered (WW) ?0.10 MPa; water-stressed (WS) ?0.86 MPa) were applied for 61 days. At the end of this experiment, G. mosseae and G. constrictum had colonized the roots of S. davidii seedlings. Water stress inhibited AM colonization, plant growth, chlorophyll concentration, gas exchange and chlorophyll fluorescence of S. davidii seedlings. Mycorrhizal seedlings had greater shoot dry weight, root dry weight, plant height, root length, instantaneous water use efficiency (iWUE), net photosynthetic rate (Pn), stomatal conductance (g_s), maximal photochemical efficiency of PSII photochemistry (Fv/Fm), lower intercellular CO₂ concentration and photochemical quenching values (qP), when compared with non-mycorrhizal seedlings under both WW and WS conditions. Furthermore, G. constrictum was found to be more efficient at improving the shoot and root mass, plant height, iWUE, Pn, g_s, qP, and ΦPSII of S. davidii seedlings, when compared with G. mosseae under both WW and WS conditions. Our results demonstrate that AM Glomus symbiosis enhanced S. davidii seedling resistance by improving its growth and physiological performance under water stress conditions. This suggests that Glomus inoculation is a potential tool for enhancing outplanting performance of S. davidii in semiarid areas of China.     

Spatiotemporal analyses of urban vegetation structural attributes using multitemporal Landsat TM data and field measurements

Key message

We conducted spatiotemporal analyses of urban vegetation structural attributes using multitemporal Landsat TM data and field measurements. We showed that multitemporal TM data has the potential of rapidly estimating urban vegetation structural attributes including LAI, CC , and BA at an urban landscape level.

Context

Urban vegetation structural properties/attributes are closely linked to their ecological functions and thus directly affect urban ecosystem process such as energy, water, and gas exchange. Understanding spatiotemporal dynamics of urban vegetation structures is important for sustaining urban ecosystem service and improving the urban environment.

Aims

The purposes of this study were to evaluate the potential of estimating urban vegetation structural attributes from multitemporal Landsat TM imagery and to analyze spatiotemporal changes of the urban structural attributes.

Methods

We first collected three scenes of TM images acquired in 1997, 2004, and 2010 and conducted a field survey to collect urban vegetation structural data (including crown closure (CC), tree height (H), leaf area index (LAI), basal area (BA), stem density (SD), diameter at breast height (DBH), etc.). We then calculated and normalized NDVI maps from the multitemporal TM images. Finally, spatiotemporal urban vegetation structural maps were created using NDVI-based urban vegetation structure predictive models.

Results

The results show that NDVI can be used as a predictor for some selected urban vegetation structural attributes (i.e., CC, LAI, and BA), but not for the other attributes (i.e., H, SD, and DBH) that are well predicted by NDVI in natural vegetation. The results also indicate that urban vegetation structural attributes (i.e., CC, LAI, and BA) in the study area decreased sharply from 1997 to 2004 but increased slightly from 2004 to 2010. The CC, LAI, and BA class distributions were all skewed toward low values in 1997 and 2004. Moreover, LAI, CC, and BA of urban vegetation all present a decreasing trend from suburban areas to urban central areas.

Conclusion

The experimental results demonstrate that Landsat TM imagery could provide a fast and cost-effective method to obtain a spatiotemporal 30-m resolution urban vegetation structural dataset (including CC, LAI, and BA).

     

Characterization of expressed genes in the establishment of arbuscular mycorrhiza between Amorpha fruticosa and Glomus mosseae

Arbuscular mycorrhiza （AM） formed between plant roots and fungi is one of the most widespread symbiotic associations in nature. To understand the molecular mechanisms of AM formation, we profiled 30 symbiosis-related genes expressed in Amorpha fruticosa roots colonized by Glomus mosseae and in non-mycorrhizal roots at different stages using differential-display RT-PCR （DDRT-PCR）. The expressed genes were confirmed by reverse Northern blotting. Eleven fragments were sequenced and putatively identified by homologous alignment. Of the eleven AM-related genes, five were obtained at the early-stage of plant-fungus interaction and six at the later stage. Three expressed se-quence tag （ESTs） sequences were found to originate from the fungi and eight from the host plant by use of PCR evaluation of gDNA of both plant and fungi. The target genes included an ATP-binding cassette sub-family transporter gene, a transposon-insertion display band, and a photosynthesis-related gene. The results provided information on the molecular mechanisms underlying the development of mycorrhizal sym-biosis between woody plants and AM fungi.     

Arbuscular mycorrhizal associations in Boswellia papyrifera (frankincense-tree) dominated dry deciduous woodlands of Northern Ethiopia

This study assessed the arbuscular mycorrhizal (AM) status of Boswellia papyrifera (frankincense-tree) dominated dry deciduous woodlands in relation to season, management and soil depth in Ethiopia. We studied 43 woody species in 52 plots in three areas. All woody species were colonized by AM fungi, with average root colonization being relatively low (16.6% – ranging from 0% to 95%). Mean spore abundance ranged from 8 to 69 spores 100 g⁻¹ of dry soil. Glomus was the dominant genus in all study sites. Season had a strong effect on root colonization and spore abundance. While spore abundance was higher (P < 0.001) in the dry season in all three study sites, root colonization showed a more variable response. Root colonization was reduced in the dry season in the site that was least subject to stress, but increased in the dry season in the harshest sites. Management in the form of exclosures (that exclude grazing) had a positive effect on spore abundance in one of the two sites considered. Spore abundance did not significantly differ (P = 0.17) between the two soil depths. Our results show that in this arid region all trees are mycorrhizal. This has profound consequences for rehabilitation efforts of such dry deciduous woodlands: underground processes are vital for understanding species adaptation to pulsed resource availability and deserve increasing attention.     

Arbuscular mycorrhizal association of indigenous agroforestry tree species and their infective potential with maize in the rift valley, Ethiopia

Tree species in agroforestry are important source of inoculum for companion agricultural crops. Agroforestry trees can serve as a source of Arbuscular mycorrhiza (AM) inoculants to intercropped annuals. We studied spore abundance, root colonization of Albizia gummifera (J.F. Gmel.) and Croton macrostachyus (Hochst Ex Del.) trees and their effect on colonization of maize. Soil and root samples were collected from field standing trees from under and outside the canopy of trees and maize crops in the main rainy season. The number of spore count was significantly higher under the canopy of A. gummifera (791/100 g of dry soil) and C. macrostachyus (877/100 g of dry soil) trees than outside the canopy (547 and 588/100 g of dry soil, respectively). The level of root colonization of C. macrostachyus (45 %) was higher than A. gummifera (41 %). Root colonization of maize crops grown under the canopy of A. gummifera and C. macrostachyus trees was significantly higher than outside the canopy (P < 0.001). Maize seedlings grown on non-sterilized soils collected under and outside the canopy of A. gummifera and C. macrostachyus trees recorded higher root colonization, plant height, shoot and root dry weight than grown on sterilized soils (P < 0.001). The percentage of AM colonized roots of Zea mays seedlings was significantly positively correlated with the number of spore counts for field soils. The rhizospheres of indigenous agroforestry perennial species are important source of inoculum for annuals. The integration of perennials and annuals in an agroforestry system enhances the maintenance of soil quality in the tropics.     

Arbuscular mycorrhizal fungi in the rhizosphere of Macaranga denticulata Muell. Arg., and their effect on the host plant

A fallow enriching tree, Macaranga denticulata Muell. Arg., has been shown to increase rice yield in a rotational shifting cultivation system in northern Thailand through increased accumulation of mineral nutrients. As arbuscular mycorrhizal (AM) fungi may play an important role in nutrient accumulation, AM fungi in the rhizosphere of M. denticulata and the effects of the indigenous soil inoculum on the host plant were investigated. The diversity and abundance of AM fungi were documented for the rhizosphere of M. denticulata in the field for two years. Based on morphology, 29 species of AM fungi were found in the rhizosphere of M. denticulata growing in farmers’ fields. Root colonization ranged from 63.5 to 81.5% in the first year and 68.7 to 79.9% in the second year of study. The highest spore density was observed at the end of the wet season. The effects of indigenous soil inoculum, and N and P fertilizers on the host plant were investigated in pots for four months. Inoculation with soil-containing AM fungi strongly increased plant growth and nutrient contents when P was limiting but N was applied. Application of N and P together strongly depressed root colonization and spore density of AM fungi, whereas applying them separately had much less effect. AM fungi may play an important role in nutrient accumulation in M. denticulata-rich fallow and thus in nutrient cycling that is beneficial to the maintenance of upland rice yield and sustainability of the rotational shifting cultivation system. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effect of the arbuscular mycorrhizae <Emphasis Type="Italic">Glomus fasciculatum</Emphasis> and <Emphasis Type="Italic">G. macrocarpum</Emphasis> on the growth and nutrient content of <Emphasis Type="Italic">Cassia siamea</Emphasis> in a semi-arid Indian wasteland soil

The effect of two arbuscular mycorrhizal (AM) fungi, Glomus fasciculatum and G. macrocarpum on shoot and root dry weights and nutrient content of Cassia siamea in a semi-arid wasteland soil was evaluated. Under nursery conditions, mycorrhizal inoculation improved growth of seedlings. Root and shoot dry weights were higher in mycorrhizal than non-mycorrhizal plants. The concentration of P, K, Cu, Zn and Na was significantly higher in AM inoculated seedlings than in non-inoculated seedlings. Mycorrhization led to decrease in alkalinity of the rhizosphere soil from pH 8.5 to 7.4. Under nursery conditions, the degree of mycorrhizal dependency increased with age of C. siamea seedling. On transplantation to the field, the survival rate of mycorrhizal seedlings (75%–90%) was higher than that of non-mycorrhizal seedlings (40%). Besides better survival rate, AM inoculation improved the growth performance of seedlings in terms of height and stem diameter. Among the two AM fungi used, the efficiency of Glomus macrocarpum was higher than that of G. fasciculatum under both nursery and field conditions.This revised version was published online in May 2005 with corrected page numbers.     

不同内外生菌根菌接种对米老排苗期的生长效应

9 mycorrhizal fungi, including 4 ectomycorrhizal fungi (ECMF) and 5 arbuscular mycorrhizal fungi (AMF), were used to explore their effect on seedling growth of Mytilaria laosensis. The study shows that M. laosensis is one of the species with both VAM and ECM. Mycorrhizal infection rate of all ECM inoculation methods reached level 3, and that of AMF infection rate was 88%-93%, of which AM91 became the highest. In different periods, different inoculation treatment expressed different effects on seedling growth. At the end of the experiment, the height, ground diameter, underground dry mass and upper ground dry mass of seedling inoculated with PX0801 and 9006 respectively increased by 71%, 45%, 128%, 184%, and 65%, 54%,150%, 208%, which exhibited the best overall effect. Coinoculated seedlings with AM90036, AM3008 and AM91 had advantages over uninoculated ones in all the tested growth indicators, which suggest to significantly promote the growth of M.laosensis. The results obtained provide reference for mycorrhizal fungi application on M. laosensis.     

Growth and nutrient concentration of two native forage legumes inoculated with Rhizobium and Mycorrhiza in Missouri, USA

The Center for Agroforestry at the University of Missouri has tested numerous native legumes for potential use in agroforestry and selected Illinois bundleflower (Desmanthus illinoensis (Michaux) MacMillan ex Robinson and Fern.) and panicled tick clover (Desmodium paniculatum (L.) DC.) for further testing. Our objective was to document the effect of arbuscular mycorrhizae (AM) (Glomus spp.) and Rhizobium on growth and nutrient concentration of these legumes. Seeds were planted in a greenhouse and inoculated with one of two species of AM and/or one of two strains of Rhizobium. Plants were harvested after 80 d and data taken on leaf and stem dry weight, root fresh weight, stem height, nodulation, AM colonization, and N, P, K, Ca, and Mg concentration. Inoculation with Rhizobium did not affect plant growth in Illinois bundleflower, but colonization by Glomus intraradices increased all plant growth variables except stem height. Nutrient concentration was unaffected by the presence of either endophyte. In contrast, inoculation of panicled tick clover with Rhizobium str. 41Z10 increased leaf dry weight (32%) compared to the control and root fresh weight (41%) compared to str. 32Z3, and colonization by G. intraradices increased leaf dry weight (35%) and stem height (26%). Both species of AM increased P and K concentration (41% and 55%, respectively) in panicled tick clover. Our results suggest that the growth of these legumes can be improved by the use of proper AM species and/or Rhizobium strains. However, additional research to identify the best Rhizobium and AM inoculates for these plant species is important in developing strategies for their use in agroforestry. This revised version was published online in June 2006 with corrections to the Cover Date.     

丙烯酸/丙烯酰胺共聚吸水树脂竞聚率及吸液性能

采用溶液聚合方法,以丙烯酸(AA)与丙烯酰胺(AM)为单体,N,N'-亚甲基双丙烯酰胺(NMBA)为交联剂,过硫酸钾(KPS)为引发剂合成了高吸水性二元树脂——聚丙烯酸-丙烯酰胺(PAAAM),并进行了吸液性能研究.结果表明,该树脂吸水倍率达2 451 g/g,吸生理盐水倍率达119 g/g.考察了n(AM)∶n(AA)摩尔配比对PAAAM的吸蒸馏水、0.9%NaCl溶液中的吸液性能,得到不能仅靠改变单体的摩尔比来改善PAAAM的吸液性能,合成PAAAM的相对较佳反应条件有赖于更具体细致的试验设计才能得以确定.反复吸水次数越多,PAAAM的吸液倍率不断下降.通过元素分析法测定了AM/AA共聚吸水树脂的竞聚率,AM和AA两单体的竞聚率分别为0.943、0.791.     

松毛虫早期灾害点遥感监测研究初报

松毛虫早期灾害点遥感监测研究初报武红敢，黄建文，乔彦友（中国林业科学研究院资源信息所北京１００００１）严小君，陈林洪（浙江省江山市森林防疫站江山３２４１００）关键词松毛虫害，ＴＭ数据，影像，监测松毛虫为我国最为严重的森林害虫［１］。几十年来，各级政府...