Acreage and production estimation of mango orchards using Indian Remote Sensing (IRS) satellite data

In order to exploit the potential of remote sensing in the field of horticulture, a study was initiated to estimate acreage and production of mango orchards using Indian Remote Sensing (IRS) satellite data. The data from linear imaging self scanning (LISS) II of IRS 1B and IRS 1C LISS III data covering the study area have been used. The boundary mask as well as sample segment approaches were tried for acreage estimation. Available yield data and meteorological and growth parameter data were collected to develop an agro-meteorological model. The study has clearly demonstrated the usefulness of LISS II and LISS III data for identifying and estimating mango orchard acreage. It was observed that use of LISS III is better compared to LISS II as the spatial resolution has improved the classification using maximum likelihood algorithm. The study also indicated that the condition of orchards could also be assessed to some extent. Total enumeration technique using summer season data gave very accurate acreage estimates of mango. The sampling approach is also good for mango orchard acreage estimation which provided almost the same accuracy as total enumeration technique but by saving about 6–8 times the analysis time and cost. Due to non-availability of reliable data at different levels, it was difficult to develop any regional level single yield model. However, it was observed that an agro-meteorological data-based model could be developed by collecting such data for 3–4 years in selected orchards.     

遥感技术城市环境与生态研究中的应用

论述了遥感技术在城市环境调查监测和生态研究中的应用现状,指出存在的问题,提出了加强城市生态环境理论研究和建设数字化城市管理信息系统的建议.     

遥感技术在城市环境与生态研究中的应用

论述了遥感技术在城市环境调查监测和生态研究中的应用现状,指出存在的问题,提出了加强城市生态环境理论研究和建设数字化城市管理信息系统的建议。     

Remote Sensing in Landscape Ecology: Experiences and Perspectives in a European Context

That the relationship between remote sensing and landscape ecology is significant is due in large part to the strong spatial component within landscape ecology. However it is nevertheless necessary to have frequent overview of the interface between remote sensing and landscape ecology, particularly in the light of developments in the types of image data and techniques. The use of remote sensing within European landscape ecology provides a rich range of examples of the interface, including application of some of the latest types of image data. This paper is an overview of the interface that remote sensing has with European landscape ecology, with seven examples of the application of image data in European landscape ecology and examination of associated landscape classification issues. These examples are discussed in terms of the trends and the different roles for image data in landscape ecology that they illustrate, and in particular their classificatory and informational implications. It is suggested that with regard to classification there is a need for re-examination of the roles of image data.     

Open woodland and savanna decline in a mixed-disturbance landscape (1938 to 1998) in the Northwest Wisconsin (USA) Sand Plain

Our research illustrates how a landscape mosaic changes in association with a mixed natural-anthropogenic disturbance history. Our study area is the Northwest Wisconsin (USA) Sand Plain (NWSP), a region with a rich disturbance history including fire, insects and clearcut forestry. We integrated historic airphotos from 1938, 1960, 1980 and 1998 within a GIS to describe change among four landcover classes describing a canopy-closure gradient: closed forests, woodlands, savannas and “open barrens”. Our work addresses two literature needs: empirical studies of mixed-disturbance landscapes, and nonforest habitats within a forest matrix. Our analysis shows that: the area of open barrens fluctuated, woodlands and savannas declined severely and closed forests increased through time. Falling median patch sizes and other landscape metrics suggest that the woodlands are becoming more fragmented. The landcover transitions driving this change vary according to time and place. The dominant transitions are toward closed forests from all classes, and transitions toward open barrens are also consistently important. The woodlands, savannas and open barrens habitats are mostly comprised of transient patches, persisting for less than 20 years. This contrasts with closed forests that often persist for 40 plus years. These changes are consistent with the disturbance regime that is shifting from fire- to forestry-dominance. Our results show a trend towards landscape simplification, manifest as losses of intermediate-density habitats (woodland and savanna) and shrinking patch sizes. The transient nature of the nonforest habitats shows that disturbance resulting in total or partial canopy removal will be vital for their conservation at a landscape scale.     

Determination of Some Engineering Properties of Pecan (Carya illinoinensis) for New Design of Cracking System

In this study, strength and frictional properties of pecan was determined as a functional of moisture content. A pecan was loaded between two parallel plates to determine the rupture force, deformation, power and firmness required to initiate pecan rupture and determined static and dynamic friction. The tests were carried out at five moisture contents of 5.23?%, 10.36?%, 15.78?%, 20.08?% and 25.42?% db and three axes (X, Y, Z). Physical characteristics of the pecan such as mass, dimensions (length, thickness and width), geometric mean diameter, sphericity, volume, and shell thickness were determined. The force required to initiate nut rupture decreased from 112.321 to 98.723 N, from 82.872 to 63,988 N and from 80.093 to 62.758 N for the length, suture and width orientations of loading with an increase in moisture content. The highest toughness (20.460 Jmm^??3) was obtained at moisture content of 25.42?% db. The firmness decreased to a minimum value when moisture content was increased from 5.23 to 10.36?% db and later increased as moisture content was increased further from 10.36 to 25.42?% db. The static and dynamic coefficients of friction on various surfaces, namely, plywood, mild steel and galvanized metal also increased linearly with increase in moisture content. The plywood surface offered the maximum friction followed by mild metal and galvanized metal.     

凤仙花属部分植物的花粉形态

 利用扫描电镜对10种国产凤仙花属( Impatiens L. ) 植物的花粉形态进行了观察。结果表明: 本属植物花粉为单粒花粉, 左右对称, 大小为1510～3112μm ×2511～4211μm, 具角萌发孔, 4沟, 沟细 而短; 花粉外壁具网状纹饰, 网眼明显, 大小不一。根据花粉形状, 可将凤仙花属花粉分为近圆形、椭圆 形和矩圆形3类。种间花粉差异主要表现在大小、形状、网脊宽度、网眼内附属物等方面。花粉特征与植 物表型特征之间存在一定的相关性, 具有重要的分类学意义。从花粉萌发孔类型来看, 与水角属(Hydrocera Bl. ) 的3沟花粉相比, 凤仙花属在凤仙花科内处于较为进化的位置。     

Accessibility to urban parks: Comparing GIS based measures in the city of Padova (Italy)

Accessibility to urban green spaces is essential for urban dwellers’ health and well-being. For planning purposes different accessibility measures and indicators have been used. Some are only based on availability, others consider distance from residences, yet others rely on gravity-based methods that consider both supply and demand. Different indicators often provide diverse and sometimes contradictory results and many issues remain in developing a comprehensive measure of accessibility, and representativity problems remain in matching indices with reality. In this study different accessibility measures have been developed and applied to the urban parks of the city of Padova, in northeastern Italy. Effectiveness and reliability of ten indicators derived from these measures, in identifying needs, inadequacies and disparities in park access have been tested at the urban unit scale. The study confirmed that multiple indicators need to be used to provide a useful planning tool for the provision of adequate and equal opportunities for open space access to the citizens. The study has also shown which indicators can be replaced by each other without losing important information.     

Determination of Vegetative and Fruit Characteristics of Some Thornless Blackberry Genotypes in Hatay (Turkey)

ABSTRACT

The experiments were carried out during 2002 and 2003 at the Department of Horticulture, Faculty of Agriculture, Mustafa Kemal University, Hatay, Turkey. In this study, some vegetative and fruit quality attributes of eight blackberry genotypes (‘Jumbo’, ‘Chester Thornless’, ‘Black Satin’, ‘Navaho’, ‘Bursa 1’, ‘Bursa 2’, ‘Bursa 3’, ‘Bartm’) were evaluated in 2002 and 2003. The greatest cane numbers and cane lengths were recorded for ‘Bursa 2’. They were followed by ‘Bursa 3’ and ‘Chester Thornless’ in both years. Harvest periods ranged from 8 to 44 days and occurred from the middle of June until the end of August. ‘Jumbo’ and ‘Bursa 1’ were the earliest ripening cultivars. ‘Bursa 2’ had the longest harvest period. The highest yields were obtained from ‘Bursa 1,’ ‘Bursa 2’ and ‘Chester Thornless.’ ‘Jumbo’ had the largest fruits. The highest TSS/TA ratio was found in ‘Navaho’.     

湖南早春露地瓠瓜栽培管理技术

瓠瓜[Lagenaria siceraria (Molina) Standl.]又称葫芦、瓠子、蒲子、长瓜等,为葫芦科葫芦属一年生攀缘草本植物[1].瓠瓜味道鲜美,营养丰富,是我国长江流域及南方各省重要的瓜类蔬菜之一,深受广大城乡居民的喜爱[2].早春季节湖南地区存在较明显的"春淡"现象,而瓠瓜生育期短、可耐受一定的低...     

GIS analysis of spatial patterns of human-caused wildfire ignition risk in the SW of Madrid (Central Spain)

The majority of wildfires in Spain are caused by human activities. However, much wildfire research has focused on the biological and physical aspects of wildfire, with comparatively less attention given to the importance of socio-economic factors. With recent changes in human activity and settlement patterns in many parts of Spain, potentially contributing to the increases in wildfire occurrence recently observed, the need to consider human activity in models of wildfire risk for this region are apparent. Here we use a method from Bayesian statistics, the weights of evidence (WofE) model, to examine the causal factors of wildfires in the south west of the Madrid region for two differently defined wildfire seasons. We also produce predictive maps of wildfire risk. Our results show that spatial patterns of wildfire ignition are strongly associated with human access to the natural landscape, with proximity to urban areas and roads found to be the most important causal factors We suggest these characteristics and recent socio-economic trends in Spain may be producing landscapes and wildfire ignition risk characteristics that are increasingly similar to Mediterranean regions with historically stronger economies, such as California, where the urban-wildland interface is large and recreation in forested areas is high. We also find that the WofE model is useful for estimating future wildfire risk. We suggest the methods presented here will be useful to optimize time, human resources and fire management funds in areas where urbanization is increasing the urban-forest interface and where human activity is an important cause of wildfire ignition.     

碳源浓度对丽石黄衣组织培养的影响

根据已有的地衣培养方法,在BBM培养基和麦芽汁-酵母膏培养基上,研究不同碳源浓度对酵母膏培养黄属丽石黄衣的影响。结果表明:碳源浓度对丽石黄衣组织培养有一定的影响,尤其是在麦芽汁-酵母膏培养基中,随着麦芽汁浓度增加,子囊盘生长速度加快;得出麦芽汁-酵母膏培养基(麦芽汁浓度30 g/L)是较好的丽石黄衣培养基,比BBM培养基更能促进丽石黄衣生长。     

柑桔种质资源对脚腐病的抗性鉴定

采用刻伤接种柑桔脚腐病病原菌(Phytophthora parasitica),观察51个柑桔种质资源对柑桔脚腐病的抗病程度。测定结果表明:枳、枳橙、枳柚、大叶金豆、酸橙等19个种类或品种对脚腐病具有高抗或抗病性;福桔、尤力克柠檬等14种材料为感病或重感病型;其余18个为中抗或中感型。其中,高抗类型大叶金豆(Fortunella hindsii var.chintou)为首次报道。     

部分板栗品种遗传多样性的AFLP分析

利用荧光标记AFLP技术,采用7对M+3和E+3引物组合对30份板栗和日本栗栽培品种进行了总基因组DNA水平上的多态性检测,共获得962条可统计的条带,其中852条呈多态性,多态性带百分率达89％。揭示了板栗丰富的遗传多样性。7组引物在30个品种中检测到数目不等的品种特异带型,对供试板栗品种具有一定的鉴别价值。7对引物能将30个板栗和日本栗品种完全区分开。聚类分析结果表明,多数来源地相同的板栗品种资源表现出较为密切的亲缘关系。     

Effects of Different Drying Methods on Some Physical and Chemical Properties of Loquat (Eriobotrya japonica) Fruits

ABSTRACT

In this communication, we have discussed and compared the different drying processes i.e. flat plate solar collector, open sun and mechanical dryer with the preservative solution of Sodium Benzoate. Loquats were pretreated with preservative solution and subject to the drying process. Drying kinetics in terms of moisture lost per hour and drying rate, texture and antioxidants retention were determined before and after drying. Statistical analysis of the data showed that the different drying process has significantly affected on the kinetics of loquat fruits with the confidence interval of (α ≤ 0.05), whereas the preservative solution showed a non-significant effect on texture and antioxidants retention. High moisture lost per hour (5.4%) was recorded in mechanical dryer followed by flat plate solar collector dryer (3.7 %) while minimum (1.8%) was recorded in open sun drying. Good textured dried loquat with optimum hardness (313 g) and stiffness (141 g mm^?1) was found in flat plate solar collector dried samples. Similarly more antioxidants (52%) retained in samples dried with hot air using flat plate solar collector followed by the mechanical dryer (47%) while minimum (41%) was recorded in open sun drying. Although mechanical drying is fast, it does not help to maintain a good texture and more antioxidants. From the study, it was concluded that hot air drying using a flat plate solar collector is better for drying process to get valuable dried loquat with good texture and more antioxidants.     

Some Aspects of the Biology of the Raspberry Leaf and Bud Mite (Phyllocoptes (Eriophyes) Gracilis Nal.) Eriophyidae in Scotland

In Scotland the raspberry leaf and bud mite (Phyllocoptes (Eriophyes) gracilis ) is widespread on cultivated and wild raspberries. However, feeding damage to leaves and fruits is usually observed only on raspberries grown in sheltered situations, where mites tend to aggregate. Female mites overwinter in the buds, under bud scales or in petiole scars. In the spring they disperse to the emerging foliage of the fructo-canes where they feed and lay eggs. Populations reach a maximum on the fructo-canes in mid-July, when the first fruits are maturing, and on the primo-canes in late September. Migration to the overwintering sites begins in late September. Cultivars differ in the extent to which they support overwintering populations and show symptoms of infestation.     

Some determinants of the spatio-temporal fire cycle in a mediterranean landscape (Corsica,France)

Based on recent needs to accurately understand fire regimes and post-fire vegetation resilience at a supra-level for carbon cycle studies, this article focusses on the coupled history of fire and vegetation pattern for 40 years on a fire-prone area in central Corsica (France). This area has been submitted since the beginning of the 20^th century to land abandonment and the remaining land management has been largely controlled by frequent fires. Our objectives were to rebuild vegetation and fire maps in order to determine the factors which have driven the spatial and temporal distribution of fires on the area, what were the feed backs on the vegetation dynamics, and the long-term consequences of this inter-relationship. The results show a stable but high frequency of small fires, coupled with forest expansion over the study period. The results particularly illustrate the spatial distribution of fires according to topography and vegetation, leading to a strong contrast between areas never burnt and areas which have been burnt up to 7 times. Fires, when occuring, affect on average 9 to 12% of the S, SE and SW facing slopes (compared to only 2 to 5% for the N facing slopes), spread recurrently over ridge tops, affect all the vegetation types but reburn preferentially shrublands and grasslands. As these fire-proning parameters have also been shown to decrease the regeneration capacity of forests, this study highlights the needs in spatial studies (both in terms of fire spread and vegetation dynamic) to accurately apprehend vegetation dynamic and functionning in fire-prone areas.This revised version was published online in May 2005 with corrections to the Cover Date.