Faculty Opinions recommendation of More diverse tree communities promote foliar fungal pathogen diversity, but decrease infestation rates per tree species, in a subtropical biodiversity experiment.

This study was conducted at Pulau Jerejak, Penang to determine the floristic variation of its tree communities. A 0.5-hectare study plot was established and divided into 11 subplots. A total of 587 trees with diameter at breast height (DBH) of 5 cm and above were measured, identified and recorded. The tree communities comprised of 84 species, 63 genera and 32 families. The Myrtaceae was the most speciose family with 10 recorded species while Syzgium glaucum (Myrtaceae) was the most frequent species. The Myrtaceae recorded the highest density of 306 individuals while Syzgium glaucum (Myrtaceae) had the highest species density of 182 individuals. Total tree basal area (BA) was 21.47 m2/ha and family with the highest BA was Myrtaceae with 5.81 m2/ha while at species level, Syzgium glaucum (Myrtaceae) was the species with the highest total BA in the plot with value of 4.95 m2/ha. The Shannon˗Weiner Diversity Index of tree communities showed a value of 3.60 (H'max = 4.43) and Evenness Index of 0.81 which indicates high uniformity of tree species. The Margalef Richness Index (R') revealed that the tree species richness was 13.02. Myrtaceae had the highest Importance Value of 20.4%. The Canonical Correspondence Analysis (CCA) showed that Diospyros buxifolia (Ebenaceae) and Pouteria malaccensis (Sapotaceae) were strongly correlated to low pH. Dysoxylum cauliflorum (Meliaceae) and Eriobotrya bengalensis (Rosaceae) were correlated to phosphorus (P) and calcium ion (Ca2+), respectively. Therefore, the trees species composition at Pulau Jerejak showed that the biodiversity is high and conservation action should be implemented to protect endangered tree species. Keywords: Floristic variation; Tree communities; Trees composition; Pulau Jerejak; Species diversity

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A Review of Corynespora cassiicola and Its Increasing Relevance to Tomato in Florida

Plant Health Progress ◽

10.1094/php-05-18-0023-rv ◽

2018 ◽

Vol 19 (4) ◽

pp. 303-309 ◽

Cited By ~ 4

Author(s):

Keevan J. MacKenzie ◽

Leilani G. Sumabat ◽

Katia V. Xavier ◽

Gary E. Vallad

Keyword(s):

Fungal Pathogen ◽

Effective Control ◽

Corynespora Cassiicola ◽

Varietal Resistance ◽

Vegetable Crop ◽

Fresh Market ◽

Resistance Development ◽

Pathogen Diversity ◽

Target Spot ◽

Insight Into

Corynespora cassiicola is a highly diverse fungal pathogen that can infect more than 500 species of plants, including many economically important crops such as cotton, soybean, tomato, and cucumber. In Florida, the number one vegetable crop by market value are fresh-market tomatoes, which generate nearly half a billion dollars annually. Florida’s subtropical to tropical climate is conducive to infection and development of the target spot pathogen on tomato caused by C. cassiicola. There is no varietal resistance available for target spot of tomato, and preventative fungicide treatments are the primary method for control. In the last decade, C. cassiicola has been more frequently reported by Florida tomato growers, appearing not only more aggressive but also increasingly insensitive to various fungicides. This review brings together the most recent C. cassiicola literature, providing a history and understanding of the immense pathogen diversity and its relevance to tomato. It also provides insight into fungicide resistance development and pathogen survivability, which are important factors in providing effective control recommendations and in understanding the epidemiology of this disease, respectively.

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Impact of Non-Timber Forest Product Use on the Tree Community in North-Western Vietnam

Forests ◽

10.3390/f9070431 ◽

2018 ◽

Vol 9 (7) ◽

pp. 431 ◽

Cited By ~ 2

Author(s):

Thi Dao ◽

Dirk Hölscher

Keyword(s):

Tree Species ◽

Logistic Model ◽

Forest Products ◽

Buffer Zone ◽

Forest Types ◽

Tree Community ◽

Tree Communities ◽

Non Timber Forest Products ◽

Forest Use ◽

North Western

Trees providing non-timber forest products (NTFPs) are valuable forest resources, and their management can support conservation objectives. We analyzed the abundance of tree species providing NTFPs, recognized by local H’mong people, in both the strictly protected core zone and the low-intensity forest use buffer zone in north-western Vietnam. We identified 249 tree species, of which 48% were classified as NTFP species. The abundance of 35% of the NTFP tree species was significantly correlated with footpaths, indicating an influence of human activity. A multiple logistic regression model indicates that using NTFP trees for food, medicine, and root harvesting, increases the probability of an NTFP tree absence in the buffer zone. In contrast, the high density of species, and collections of fruit, leaf, and resin decrease the probability of an NTFP tree absence in the buffer zone. Further assessment with a logistic model indicated that NTFP use has lower impacts on the tree community than timber use. We think that the parameterized models will enable comparisons of different situations and forest types and be particularly helpful in evaluating potential changes in tree communities over time.

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Specialization of a fungal pathogen on host tree species in a cross-inoculation experiment

Journal of Ecology ◽

10.1111/j.1365-2745.2011.01869.x ◽

2011 ◽

Vol 99 (6) ◽

pp. 1394-1401 ◽

Cited By ~ 30

Author(s):

Miki Konno ◽

Susumu Iwamoto ◽

Kenji Seiwa

Keyword(s):

Tree Species ◽

Fungal Pathogen ◽

Host Tree ◽

Inoculation Experiment ◽

Host Tree Species

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Antimicrobial Screening of Some Exotic Tree Species of Rajasthan Desert

Indian Journal of Pharmaceutical and Biological Research ◽

10.30750/ijpbr.1.3.2 ◽

2013 ◽

Vol 1 (03) ◽

pp. 08-11

Author(s):

B. B.S. Kapoor ◽

Shelja Pandita

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Candida Albicans ◽

Ethyl Ether ◽

Tree Species ◽

Fungal Pathogen ◽

Antimicrobial Screening ◽

Kigelia Pinnata ◽

Exotic Tree ◽

Putranjiva Roxburghii

Antimicrobial screening of ethyl ether and alcoholic extracts of leaves of four selected exotic tree species growing in Rajasthan Desert was carried out. Colophospermum mopane, Holoptelea integrifolia, Kigelia pinnata and Putranjiva roxburghii showed positive reactions against bacterial pathogens i.e. Staphylococcus aureus, Escherichia coli and a fungal pathogen Candida albicans.

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Diversity of Botryosphaeriaceae species associated with Chinese hickory tree (Carya cathayensis) trunk cankers

Plant Disease ◽

10.1094/pdis-02-21-0289-re ◽

2021 ◽

Author(s):

C. J. Zhuang ◽

Q. W. Wang ◽

Q. Q. Wu ◽

Z. L. Qiu ◽

B. C. Xu ◽

...

Keyword(s):

Spore Germination ◽

Fungal Pathogen ◽

Mycelial Growth ◽

Optimum Temperature ◽

Botryosphaeria Dothidea ◽

Pathogen Diversity ◽

New Information ◽

Different Temperatures ◽

Carya Cathayensis ◽

Botryosphaeriaceae Species

Tree trunk cankers (TRC) represent serious fungal diseases that pose significant threats to Chinese hickory trees (Carya cathayensis). To characterize the pathogen diversity associated with, diseased tissues were collected between 2016 and 2018 from the primary Chinese hickory plantation regions. A total of 97 cultures were isolated from trees in six towns (Longgang, Qingliangfeng, Changhua, Tuankou, Taiyang Town, and Lin’an urban area) within the Linan district, where 60% of Chinese hickory tree yields originate. The isolated cultures caused cankers on Chinese hickory tree branches, but infections did not occur on fruits or leaves under tested conditions. Combined morphological observations and phylogenetic analysis of multiple genes (ITS, β-tublin, and EF) indicated that five Botryosphaeriaceae species were recovered, including 89 isolates of Botryosphaeria dothidea, four isolates of B. fabicerciana, one isolate of B. qingyuanensis, one isolate of B. corticis, and two isolates of Lasiodiplodia theobromae. B. dothidea was the most prevalent, and this is the first report of B. corticis, B. qingyuanensis, and L. theobromae infections in Chinese hickory trees. We investigated the mycelial growth, spore germination, and pathogenicity of these species at different temperatures. L. theobromae grew the fastest and B. cortices grew the slowest on PDA. The optimum temperature of spore germination for all species was 30°C. L. theobromae was the most virulent species, followed by B. dothidea and B. qingyuanensis, then B. fabicerciana, and finally B. cortices. These new insights into fungal pathogen diversity provide critical new information to understand and manage TRC of Chinese hickory.

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Tree communities of white-sand and terra-firme forests of the upper Rio Negro

Acta Amazonica ◽

10.1590/s0044-59672011000400010 ◽

2011 ◽

Vol 41 (4) ◽

pp. 521-544 ◽

Cited By ~ 31

Author(s):

Juliana Stropp ◽

Peter Van der Sleen ◽

Paulo Apóstolo Assunção ◽

Adeilson Lopes da Silva ◽

Hans Ter Steege

Keyword(s):

Species Composition ◽

Tree Species ◽

Large Scale ◽

Species Abundance ◽

Tree Diversity ◽

Terra Firme ◽

Floristic Similarity ◽

White Sand ◽

Rio Negro ◽

Tree Communities

The high tree diversity and vast extent of Amazonian forests challenge our understanding of how tree species abundance and composition varies across this region. Information about these parameters, usually obtained from tree inventories plots, is essential for revealing patterns of tree diversity. Numerous tree inventories plots have been established in Amazonia, yet, tree species composition and diversity of white-sand and terra-firme forests of the upper Rio Negro still remain poorly understood. Here, we present data from eight new one-hectare tree inventories plots established in the upper Rio Negro; four of which were located in white-sand forests and four in terra-firme forests. Overall, we registered 4703 trees > 10 cm of diameter at breast height. These trees belong to 49 families, 215 genera, and 603 species. We found that tree communities of terra-firme and white-sand forests in the upper Rio Negro significantly differ from each other in their species composition. Tree communities of white-sand forests show a higher floristic similarity and lower diversity than those of terra-firme forests. We argue that mechanisms driving differences between tree communities of white-sand and terra-firme forests are related to habitat size, which ultimately influences large-scale and long-term evolutionary processes.

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Relationship Between Genetic Variation and Diversity of Tree Species in Tropical Forests in the El Ocote Biosphere Reserve, Chiapas, Mexico

Tropical Conservation Science ◽

10.1177/1940082920978143 ◽

2021 ◽

Vol 14 ◽

pp. 194008292097814

Author(s):

Bárbara Cruz-Salazar ◽

Lorena Ruiz-Montoya ◽

Neptalí Ramírez-Marcial ◽

Maricela García-Bautista

Keyword(s):

Genetic Diversity ◽

Genetic Variation ◽

Species Diversity ◽

Tree Species ◽

Haplotype Diversity ◽

Biosphere Reserve ◽

Genetic Distances ◽

Community Diversity ◽

Environmental Selection ◽

Tree Communities

Knowledge of the genetic diversity of species in a biological community is useful for assessing the ecological and evolutionary processes that define the structure and dynamics of that community. We investigated the potential relationship between the trans-specific genetic diversity (or genetic diversity across tree species) and the diversity of tree species in a tropical subdeciduous forest. The nucleotide variation of the concatenated regions ITS 1 and ITS 3 (ITS1-3) was used to determine the trans-specific genetic diversity of 19 species of trees in five local communities at El Ocote Biosphere Reserve (REBISO), Chiapas, Mexico. Tree diversity was obtained by counting individual trees within 0.1 ha circular plots in each locality. The relationship between trans-specific genetic diversity and species diversity was established through simple linear regressions between genetic diversity parameters and community diversity. A correlation matrix was built with genetic distances (Kimura’s two-parameter model) and differences in species diversity between communities. A significant relationship was observed between nucleotide diversity (π) and species richness ( Sp), and a negative association between haplotype diversity and gamma diversity (γ). Our results show species-rich and genetically diverse tree communities and a weak association between trans-specific genetic variation and species diversity in tree communities at REBISO. This research suggests a possible ecological and genetic relationship within each community. Genetic diversity values may provide an important degree of variation upon which environmental selection pressures could operate, which may be helpful to face the current environmental modifications associated with climatic change.

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Excluding Large Wild Herbivores Reduced Norway Spruce Dominance and Supported Tree Species Richness in a Young, Naturally Regenerated Stand

Forests ◽

10.3390/f12060737 ◽

2021 ◽

Vol 12 (6) ◽

pp. 737

Author(s):

Bohdan Konôpka ◽

Vladimír Šebeň ◽

Jozef Pajtík ◽

Lisa A. Shipley

Keyword(s):

Species Richness ◽

Norway Spruce ◽

Tree Species ◽

Tree Height ◽

Shannon Index ◽

Ecosystem Dynamics ◽

Large Herbivores ◽

Tree Species Richness ◽

Tree Communities ◽

Broadleaved Tree Species

Large wild herbivores are important and natural components of forest ecosystems, but through their browsing activities have the potential to influence the structure and composition of forest communities, thus timber production and ecosystem dynamics. To examine the effects of browsing by wild herbivores on a young post-disturbance forest in the Kysuce region of northwestern Slovakia, we established two sets of 2 m radius plots, 15 within a fenced area (5.12 ha) that excluded large wild herbivores, and 15 within an adjacent unfenced area. In each plot, we recorded the species, tree height, stem base diameter, and mutual geographic positions of trees. When we compared tree community characteristics between the unfenced and fenced plots, we found fewer and smaller broadleaved tree species, except silver birch (Betula pendula Roth.) in the unfenced plots. Although common rowan (Sorbus aucuparia L.) was the dominant species within fenced plots, where some individuals were over 6.0 m tall, this species was rare outside the fenced area and usually did not exceed 1.5 m. In contrast, Norway spruce (Picea abies Karts L.) was more abundant and taller within the unfenced area, likely released from competition by suppression of broadleaved trees by herbivores. In addition, fenced plots also showed twice the tree species richness (Shannon index) of unfenced ones. Despite changes in tree communities, total aboveground biomass stock was only slightly but significantly lower in the unfenced than the fenced plots (29.6 kg per 10 m2 vs. 33.5 kg per 10 m2). Our study suggested that browsing pressure by large wild herbivores that focused on most broadleaved trees weakened interspecies competition and allowed the expansion of Norway spruce. As a consequence, converting spruce monocultures to mixed species stands is likely unrealistic when faced with heavy browsing pressure by wild large herbivores.

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