scholarly journals Assessment and Distribution of Damages Caused by the Trunk-Boring Insects Coraebus undatus (Fabricius) (Coleoptera: Buprestidae) and Reticulitermes grassei Clément (Blattodea: Rhinotermitidae) in Mediterranean Restored Cork-Oak Forests

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1501
Author(s):  
Ana M. Cárdenas ◽  
Dafne Toledo ◽  
Patricia Gallardo ◽  
José Guerrero-Casado
Keyword(s):  
Distribution Patterns ◽  
Research Area ◽  
Cork Oak ◽  
Background Information ◽  
Oak Forests ◽  
Trunk Diameter ◽  
Solar Exposure ◽  
Natural Park ◽  
Extraction Period ◽  
Trunk Orientation

This work assesses damage caused by Coraebus undatus (Fabricius) (Coleoptera: Buprestidae) and Reticulitermes grassei Clément (Blattodea: Rhinotermitidae) in managed cork oak forests from the southern Iberian Peninsula. Lesions were diagnosed and quantified in relation to the following features: height and orientation in the trunk, diameter at breast height, solar exposure, understory presence and orography. The distribution patterns of lesions in the study area across 12 plots and in the trunk of the trees were also analyzed. The study was performed in “Sa de Hornachuelos” Natural Park (Córdoba, Spain) and the research area encompassed 12 environmentally-restored sampling plots. Data were recorded from 2007 to 2014, with yearly sampling from late June to mid-September, corresponding to the cork extraction period, since lesions caused by these insects are well distinguishable promptly after bark removal. The results reveal that C. undatus has low population levels and a non-uniform distribution pattern in the study area as well as in the trunk of the tree. It shows preference for medium height but not by any trunk orientation. R. grassei also shows low infestation levels and a preference to affect the trunk’s base. Comparatively, C. undatus showed higher infestation levels than R. grassei. The location of damage was also different, since galleries made by C. undatus predominated at intermediate trunk heights while those of R. grassei were more frequent at lower heights. Our results further showed a low co-occurrence of both species in the same tree trunks, which could be explained in terms of overlapping in the distribution areas of both species. These results provide background information that will enable natural resources managers to detect changes and trends of these species and inform future management decisions.

The Influence of Wharfs on School Children: A Case Study of Portee Wharf in Freetown, Sierra Leone

2019 ◽  
Vol 2 (3) ◽  
pp. 128-140
Author(s):  
Alhaji Bakar Kamara
Keyword(s):  
West Africa ◽  
Sierra Leone ◽  
School Children ◽  
Research Area ◽  
Background Information ◽  
Control Problems

The focus of this research is to investigate the influence of wharfs on school children. Therefore it will report the findings of the result on the influences of wharfs on school children with specific case on Portee Wharf in Freetown, Sierra Leone in West Africa. In this regard, the introduction describes the research area, stating the statement of the problem, the overall goal and specific objectives that will be attained in this study, justification for selecting the topic, problems to be encountered during the course of carrying out this research and major influences. Besides, an indication of the methods used to investigate the topic will also be highlighted. Moreover, the studies will analyze the actual responses of the respondents of the activities of the wharf on school-going children. It will address the questionnaire in accordance with the following: Background information of respondents, this investigated areas such as sex, age, religion, occupation and tribe; It enquires about the activities of the wharfs, reasons and consequences of children engaged in wharfs and strategies to control problems that may emanate from the wharf. The paper will show the findings, gives the summary, conclusion and recommendations of problems identified while carrying out the research.

Progress and Prospects for the Development of Computer-Generated Actors for Military Simulation: Part 1-Introduction and Background

2003 ◽  
Vol 12 (3) ◽  
pp. 311-325 ◽  
Author(s):  
Martin R. Stytz ◽  
Sheila B. Banks
Keyword(s):  
Research Area ◽  
Background Information ◽  
Life Cycle Costs ◽  
Material Management ◽  
Reasoning System ◽  
Force Structure ◽  
The Cost ◽  
Future Work ◽  
Level Training ◽  
Made In

The development of computer-generated synthetic environments, also calleddistributed virtual environments, for military simulation relies heavily upon computer-generated actors (CGAs) to provide accurate behaviors at reasonable cost so that the synthetic environments are useful, affordable, complex, and realistic. Unfortunately, the pace of synthetic environment development and the level of desired CGA performance continue to rise at a much faster rate than CGA capability improvements. This insatiable demand for realism in CGAs for synthetic environments arises from the growing understanding of the significant role that modeling and simulation can play in a variety of venues. These uses include training, analysis, procurement decisions, mission rehearsal, doctrine development, force-level and task-level training, information assurance, cyberwarfare, force structure analysis, sustainability analysis, life cycle costs analysis, material management, infrastructure analysis, and many others. In these and other uses of military synthetic environments, computer-generated actors play a central role because they have the potential to increase the realism of the environment while also reducing the cost of operating the environment. The progress made in addressing the technical challenges that must be overcome to realize effective and realistic CGAs for military simulation environments and the technical areas that should be the focus of future work are the subject of this series of papers, which survey the technologies and progress made in the construction and use of CGAs. In this, the first installment in the series of three papers, we introduce the topic of computer-generated actors and issues related to their performance and fidelity and other background information for this research area as related to military simulation. We also discuss CGA reasoning system techniques and architectures.

Forecasting infestation byCoraebus undatus(Coleoptera, Buprestidae) in cork oak forests

2012 ◽  
Vol 58 (3) ◽  
pp. 275-280 ◽  
Author(s):  
A. Gallardo ◽  
A. Jiménez ◽  
C.A. Antonietty ◽  
M. Villagrán ◽  
M.E. Ocete ◽  
...  
Keyword(s):  
Cork Oak ◽  
Oak Forests

scholarly journals STRUKTUR KOMUNITAS DAN ASOSIASI LAMUN (Seagrass) DI PERAIRAN PANTAI RUA PULAU TERNATE PROVINSI MALUKU UTARA

2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Riyadi Subur
Keyword(s):  
Coastal Waters ◽  
Coastal Region ◽  
Positive Association ◽  
Distribution Patterns ◽  
Research Area ◽  
Negative Association ◽  
Line Transect ◽  
Thalassia Hemprichii ◽  
Marine Life ◽  
Cymodocea Rotundata

AbstrakLamun (Seagrass) merupakan salah satu ekosistem penting diwilayah pesisir yangberperan penting baik secara ekologis dan ekonomis. Keberadaan lamun mendukungkehidupan berbagai jenis biota laut. Penelitian ini bertujuan mengidentifikasi jenis-jenislamun yang berada di perairan pantai Rua, Mengetahui kepadatan, pola sebaran,keanekaragaman jenis, dan dominansi serta asosiasi antara spesies. Penelitian ini dilakukandengan metode garis transek dan kuadrat. Hasil penelitian menunjukkan bahwa terdapat 4jenis lamun di perairan pantai Rua yang terdiri dari Cymodocea rotundata, Enhalusacoroides, Halodule pinifolia dan Thalassia hemprichii. T. hemprichii adalah jenis dengankepadatan tertinggi di perairan Rua yaitu 16,70 ind/m2, serta E. acoroides, memilikikepadatan terendah yakni 5,77 ind/m2. Jenis lamun yang ditemukan di lokasi penelitianseluruhnya memiliki pola sebaran mengelompok dengan keanekaragaman yangdikategorikan rendah yaitu sebesar 1,32, serta indeks dominasi sebesar 0,27. Tipe asosiasilamun di lokasi penelitian yaitu asosiasi positif (+), serta asosiasi negatif (-).Kata Kunci. Struktur Komunitas, Asosiasi, lamun.AbstractSeagrass is a important ecosystems coastal region that is important both ecologically andeconomically . The seagrass supports of various marine life. This study to propose identify thespecies of seagrasses in coastal waters in Rua, Knowing the density, distribution pattern,species diversity, and dominance as well as associations between species. This study wasconducted using line transect and kuadrats. The results showed that there are 4 species ofseagrass in Rua consisting of Cymodocea rotundata , Enhalus acoroides , pinifolia Haloduleand Thalassia hemprichii . T. hemprichii is highest density (16.70 ind/m2), and E. acoroides ,which has the lowest density (5.77 ind/m2). Species seagrass found in the research area allhave clumped distribution patterns are categorized with diversity low at 1.32 , and dominanceindex at 0.27. Type association of seagrass in the location studies is positive association ( + )and negative association ( - ).Key Words:community structur, association, seagrass

scholarly journals Does Shrub Encroachment Indicate Ecosystem Degradation? A Perspective Based on the Spatial Patterns of Woody Plants in a Temperate Savanna-Like Ecosystem of Inner Mongolia, China

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1248
Author(s):  
Xiao Wang ◽  
Lina Jiang ◽  
Xiaohui Yang ◽  
Zhongjie Shi ◽  
Pengtao Yu
Keyword(s):  
Inner Mongolia ◽  
Woody Plants ◽  
Plant Cover ◽  
Distribution Patterns ◽  
Research Area ◽  
Shrub Encroachment ◽  
Point Pattern Analysis ◽  
Point Pattern ◽  
Shrub Species ◽  
Degraded Ecosystems

Shrub encroachment, i.e., shrub emergence or an increase in woody plant cover, has been widely observed in arid and semiarid grasslands and savannas worldwide since the 2000s. However, until now, there has been a clear division of opinion regarding its ecological implications. One view is that shrub encroachment is an indicator of ecological degradation, and the other is that shrub encroachment is a sign of the restoration of degraded ecosystems. This division leads to completely different judgments about the states and transition phases of shrub-encroached ecosystems, which further affects decisions about their conservation and management. To determine whether ecosystems experiencing shrub encroachment are degrading or are in a postdegraded restoration stage, the spatial distributions and interactions of woody plants after shrub encroachment were investigated in this study. An Ulmus pumila-dominated temperate savanna-like ecosystem with significant shrub encroachment in the Otindag Sandy Land, Inner Mongolia, China, was selected as the research area, and woody plants were surveyed within a 25-hectare (500 × 500 m) plot. Spatial point pattern analysis was employed to analyze the distribution patterns of the woody plants. The results indicated different patterns for U. pumila trees, i.e., a random distribution pattern for old trees (with a diameter at breast height (DBH) of more than 20 cm) and aggregated distribution patterns for medium (5 cm ≤ DBH < 20 cm) and juvenile trees (DBH < 5 cm) at scales of 0–9 and 0–12 m, respectively. For most shrubs, there was significant aggregation at a scale of 0–6 m. However, there were significant negative relationships between old U. pumila trees (DBH ≥ 20 cm) and most shrub species, such as Caragana microphylla and Spiraea aquilegifolia. In contrast, there were positive relationships between juvenile trees (DBH < 5 cm) and most shrub species. These results suggest that, to some extent, shrub encroachment may have disrupted the normal succession pattern in the U. pumila community in this area, and without conservation, the original tree-dominated temperate savanna-like ecosystem may continue to deteriorate and eventually become a shrub-dominated temperate savanna-like ecosystem.

scholarly journals An Overview of Phytophthora Species Inhabiting Declining Quercus suber Stands in Sardinia (Italy)

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 971
Author(s):  
Salvatore Seddaiu ◽  
Andrea Brandano ◽  
Pino Angelo Ruiu ◽  
Clizia Sechi ◽  
Bruno Scanu
Keyword(s):  
Rhizosphere Soil ◽  
Phytophthora Cinnamomi ◽  
Stream Water ◽  
Morphological Characters ◽  
Quercus Suber ◽  
Phytophthora Species ◽  
Cork Oak ◽  
Oak Forests ◽  
Primary Role ◽  
Ecological Value

Cork oak forests are of immense importance in terms of economic, cultural, and ecological value in the Mediterranean regions. Since the beginning of the 20th century, these forests ecosystems have been threatened by several factors, including human intervention, climate change, wildfires, pathogens, and pests. Several studies have demonstrated the primary role of the oomycete Phytophthora cinnamomi Ronds in the widespread decline of cork oaks in Portugal, Spain, southern France, and Italy, although other congeneric species have also been occasionally associated. Between 2015 and 2019, independent surveys were undertaken to determine the diversity of Phytophthora species in declining cork oak stands in Sardinia (Italy). Rhizosphere soil samples were collected from 39 declining cork oak stands and baited in the laboratory with oak leaflets. In addition, the occurrence of Phytophthora was assayed using an in-situ baiting technique in rivers and streams located throughout ten of the surveyed oak stands. Isolates were identified by means of both morphological characters and sequence analysis of internal transcribed spacer (ITS) regions of ribosomal DNA. In total, 14 different Phytophthora species were detected. Phytophthora cinnamomi was the most frequently isolated species from rhizosphere soil, followed by P. quercina, P. pseudocryptogea, and P. tyrrhenica. In contrast, P. gonapodyides turned out to be the most dominant species in stream water, followed by P. bilorbang, P. pseudocryptogea, P. lacustris, and P. plurivora. Pathogenicity of the most common Phytophthora species detected was tested using both soil infestation and log inoculation methods. This study showed the high diversity of Phytophthora species inhabiting soil and watercourses, including several previously unrecorded species potentially involved in the decline of cork oak forests.

Multi-angular observation of forest canopy reflectance based on a hyperspectral UAV imaging platform

2020 ◽  
Author(s):  
Feng Qiu ◽  
Qian Zhang
Keyword(s):  
Forest Canopy ◽  
Vegetation Indices ◽  
Canopy Structure ◽  
Distribution Patterns ◽  
Background Information ◽  
Canopy Reflectance ◽  
Bidirectional Reflectance ◽  
Forest Canopies ◽  
Ground Distance ◽  
Observation Method

&lt;p&gt;Forest canopy reflectance varies with solar and observation geometries and shows distinct anisotropic characteristics. The bidirectional reflectance distribution function (BRDF) of forest canopies is influenced by canopy structure, leaf biochemistry and background reflectance. Multi-angular remote sensing observations of forest canopies provide much more information about canopy structure and background information compared with the nadir observations. The development of unmanned aerial vehicle (UAV) provides great opportunities for multi-angular observations in forests. We developed a solid method to obtained bidirectional reflectance of forest canopies based on a hyperspectral UAV imaging platform in this study. With this multi-angular observation method, we obtained canopy reflectance images with the view zenith angle (VZA) varying from 60&amp;#176; (forward) to 60&amp;#176; (backward) at fixed interval (10&amp;#176;), as well as the hotspot and darkspot images in the principle plane in conifer forests. Since the single pixel with very high spatial resolution (around 10 cm) in the UAV images are not representative for the study of the whole forest canopy, several pixels in the central of each images were selected and averaged to determine the canopy reflectance. Variations of the averaged reflectance with ground distance represented by the selected pixels were analyzed and the optimum ground distance for study the multi-angular forest canopy reflectance was determined. The observed canopy reflectance peaks at the hotspot and clear images of the hotspot are observed. The sensitivities of canopy reflectance to VZAs vary with spectral bands. The reflectance at red bands near 680 nm are most sensitive to VZA. Some common used vegetation indices, such as NDVI, EVI, MTCI, PRI, also vary greatly with VZAs and demonstrate different spatial distribution patterns. The observations fit well with the 4-Scale geometric-optical model simulations. The multi-angular observation methods based on UAV platform have the advantages of efficient and effective in multi-angular observation with higher flexibility in VZA adjustment and lower cost, compared with the airborne or spaceborne sensors. This multi-angular observation method is very useful for study the BRDF and canopy structural and biochemical characteristics of forests and has great potential in forestry and ecological studies.&lt;/p&gt;

scholarly journals The Lichen Genus Usnea On Quercus Suber In Iberian Cork-Oak Forests

2000 ◽  
Vol 32 (1) ◽  
pp. 67-88 ◽  
Author(s):  
Simón Fos ◽  
Philippe Clerc
Keyword(s):  
Iberian Peninsula ◽  
Quercus Suber ◽  
Cork Oak ◽  
New Combination ◽  
Oak Forests ◽  
Distribution Maps

AbstractFifteen species of Usnea are recorded from Iberian cork-oak forests: U. ceratina, U. comma, U. dasaea, U. esperantiana, U. flammea, U. fulvoreagens, U. glabrata, U. hirta, U. mutabilis, U. rubicunda, U. subcornuta, U. subfloridana U. subscabrosa, U. substerilis and U. wasmuthii. A key for these species is provided. Details of morphology, chemistry, distribution, ecology and taxonomy are discussed. Usnea dasaea is reported as new to the Iberian Peninsula. New chemotypes of U. fulvoreagens (with squamatic acid) and U. wasmuthii (with psoromic acid) have been identified. Distribution maps of U. dasaeaand U. subcornuta in Europe are presented. A new combination, Usnea subfloridana subsp. praetervisa (Asahina) P. Clerc, is proposed.

Accounting for single and aggregated forest incomes: Application to public cork oak forests in Jerez (Spain) and Iteimia (Tunisia)

2008 ◽  
Vol 65 (1) ◽  
pp. 76-86 ◽  
Author(s):  
Pablo Campos ◽  
Hamed Daly-Hassen ◽  
José L. Oviedo ◽  
Paola Ovando ◽  
Ali Chebil
Keyword(s):  
Cork Oak ◽  
Oak Forests
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