scholarly journals The decay and fungal succession of apples with bitter rot across a vegetation diversity gradient

2021 ◽  
Author(s):  
Phillip L. Martin ◽  
William King ◽  
Terrence H Bell ◽  
Kari Peter
Keyword(s):  
Plant Communities ◽  
Soil Surface ◽  
Decay Rates ◽  
Gene Marker ◽  
Vegetation Diversity ◽  
Fungal Succession ◽  
Diversity Gradient ◽  
Bitter Rot ◽  
Tree Canopies ◽  
Diverse Plant

Bitter rot is a disease of apple caused by fungi in the genus Colletotrichum. Management begins with removal of infected twigs and fruits from tree canopies to reduce overwintering inoculum. Infected apples are usually tossed to the orchard floor, which is generally managed as herbicide-treated weed-free tree rows, separated by grass drive rows. We monitored decay rates and succession of fungi of apples with bitter rot in tree canopies, and on the soil surface in tree rows, grass drive rows, and nearby diverse plant communities. We hypothesized that decay would occur most rapidly within diverse plant communities, which would provide a more diverse array of potential fungal decomposers. Apples in tree canopies became dry and mummified and had more Colletotrichum gene marker copies the following growing season than did apples on the soil surface. Of the soil surface samples, those in grass drive rows and diverse plant communities had higher moisture, faster decay rates, and sharper decreases in Colletotrichum gene marker copies than apples in tree rows. Fungal composition across all decaying apples was dominated by yeasts, with higher genus-level richness, diversity, and evenness in apples from tree canopies than those on the soil surface. In soil surface apples, we observed clear successional waves of Pichia, Kregervanrija, and [Candida] yeasts, with similar but distinctly diverging fungal composition. Our results show that orchard floor management can influence fungal succession in apples with bitter rot, but suggests that bitter rot management should primarily focus on removing infected apples from tree canopies.

Invasions: the perspective of diverse plant communities

2000 ◽  
Vol 25 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Anne-Helene Prieur-Richard ◽  
Sandra Lavorel
Keyword(s):  
Plant Communities ◽  
Diverse Plant

Germination strategy of the East African savanna tree Acacia tortilis

2005 ◽  
Vol 21 (5) ◽  
pp. 509-517 ◽  
Author(s):  
Paul E. Loth ◽  
Willem F. de Boer ◽  
Ignas M. A. Heitkönig ◽  
Herbert H. T. Prins
Keyword(s):  
National Park ◽  
Laboratory Experiments ◽  
Perennial Grass ◽  
Soil Surface ◽  
Bare Soil ◽  
Acacia Tortilis ◽  
East African ◽  
Tree Canopies ◽  
Arable Fields ◽  
Germination Success

Germination of Acacia tortilis seeds strongly depends on micro-site conditions. In Lake Manyara National Park, Tanzania, Acacia tortilis occurs abundantly in recently abandoned arable fields and in elephant-mediated gaps in acacia woodland, but does not regenerate in grass swards or beneath canopies. We examined the germination of Acacia tortilis using field and laboratory experiments. Seeds placed on top of the soil rarely germinated, while seeds covered with elephant dung or buried under the soil surface had a germination success between 23–43%. On bare soil 39% of both the dung-covered and buried seeds germinated, in perennial grass swards 24–43%, and under tree canopies 10–24% respectively. In laboratory experiments, seed water absorption correlated positively with temperature up to 41 °C, while subsequent germination was optimal at lower (21–23 °C) temperatures. Seeds that had absorbed water lost their viability when kept above 35.5 °C. The absence of light did not significantly influence germination success. Acacia tortilis does not actively disperse its seeds, but regeneration outside tree canopies was substantial. The regeneration potential thus strongly depends on the physiognomy of the vegetation.

Effects of Grazing on Abundance and Distribution of Shortgrass Steppe Consumers

2008 ◽  
Author(s):  
Daniel G. Milchunas ◽  
William K. Lauenroth
Keyword(s):  
Plant Communities ◽  
Carbon Allocation ◽  
Ground Surface ◽  
Soil Surface ◽  
Bouteloua Gracilis ◽  
Shortgrass Steppe ◽  
Background Information ◽  
Long Term Effects ◽  
Grazing Effects

Although livestock are the most obvious consumers on the shortgrass steppe, they are certainly not the only consumers. However, livestock may influence the other consumers in a number of different ways. They may directly compete for food resources with other aboveground herbivores. There is behavioral interference between livestock and some species of wildlife (Roberts and Becker, 1982), but not others (Austin and Urness, 1986). The removal of biomass by livestock alters canopy structure (physiognomy) and influences microclimate. Bird, small-mammal, and insect species can be variously sensitive to these structural alterations (Brown, 1973; Cody, 1985; MacArthur, 1965; Morris, 1973; Rosenzweig et al., 1975; Wiens, 1969). There are both short- and long-term effects of grazing on plant community species composition, primary production, and plant tissue quality. Belowground consumers can also be affected by the effects of grazing on soil water infiltration, nutrient cycling, carbon allocation patterns of plants, litter accumulation, and soil temperature. The overall effects of livestock on a particular component of the native fauna can be negative or can be positive through facilitative relationships (Gordon, 1988). In this chapter we assess the effects of cattle grazing on other above- and belowground consumers, on the diversity and relative sensitivity of these groups of organisms, and on their trophic structure. We first present some brief background information on plant communities of the shortgrass steppe and on the long-term grazing treatments in which many of the studies reported herein were conducted. Details on the plant communities are presented by Lauenroth in chapter 5 (this volume), grazing effects on plant communities by Milchunas et al. in chapter 16 (this volume); and grazing effects on nutrient distributions and cycling by Burke et al. in chapter 13 (this volume). The physiognomy of the shortgrass steppe is indicated in its name. The dominant grasses (Bouteloua gracilis and Buchloë dactyloides), forb (Sphaeralcea coccinea), and carex (Carex eleocharis) have the majority of their leaf biomass within 10 cm of the ground surface. A number of less abundant midheight grasses and dwarf shrubs are sparsely interspersed among the short vegetation, but usually much of their biomass is within 25 cm of the g round. Basal cover of vegetation typically totals 25% to 35%, and is greater in long-term grazed than in ungrazed grassland. Bare ground (more frequent on grazed sites) and litter-covered ground (more frequent on ungrazed sites) comprise the remainder of the soil surface (Milchunas et al., 1989).

A synecological account of the Suikerbosrand Nature Reserve. II. The phytosociology of the Ventersdorp Geological System

Bothalia ◽  
1980 ◽  
Vol 13 (1/2) ◽  
pp. 199-216 ◽  
Author(s):  
G. J. Bredenkamp ◽  
G. K. Theron
Keyword(s):  
Plant Communities ◽  
Soil Texture ◽  
Nature Reserve ◽  
Surface Soil ◽  
Soil Depth ◽  
Soil Surface ◽  
Habitat Features ◽  
Species Groups

The vegetation of the Ventersdorp Geological System of the Suikerbosrand Nature Reserve is analysed and classified according to the Braun-Blanquet method. Descriptions of the plant communities include description of habitat features, the identification of differentiating species groups as well as the listing of prominent and less conspicuous species for the tree, shrub and herbaceous layers. The habitat features that are associated with differences in vegetation include altitude, aspect, slope, rockiness of soil surface, soil depth and soil texture.

scholarly journals Competition and facilitation structure plant communities under nurse tree canopies in extremely stressful environments

2017 ◽  
Vol 7 (8) ◽  
pp. 2747-2755 ◽  
Author(s):  
Ali A. Al-Namazi ◽  
Magdy I. El-Bana ◽  
Stephen P. Bonser
Keyword(s):  
Plant Communities ◽  
Tree Canopies ◽  
Stressful Environments

scholarly journals The phytosociology and syntaxonomy of relatively low-altitude areas in the North-eastern Mountain Sourveld, in the eastern Transvaal escarpment region

Koedoe ◽  
1994 ◽  
Vol 37 (2) ◽  
Author(s):  
W.S. Matthews ◽  
G.J. Bredenkamp ◽  
N. Van Rooyen
Keyword(s):  
Random Sample ◽  
Plant Communities ◽  
Environmental Conditions ◽  
Hierarchical Classification ◽  
Soil Surface ◽  
The North ◽  
North Eastern ◽  
Low Altitude

An analysis of the vegetation of the relatively low altitude regions of the North-eastern Mountain Sourveld of the eastern Transvaal escarpment is presented. Releves were compiled in 53 stratified random sample plots. ATWINSPAN-classification, refined by Braun-Blanquet procedures, revealed seven plant communities. In the hierarchical classification one class, one alliance, four associations, four subassociations and two valiants are recognised. Formal syntaxonomic descriptions of the syntaxa are given. All communities are related to specific environmental conditions, of which geology, aspect, altitude and rockiness of the soil surface are the most important.

Syntaxonomic diversity as an indicator of ecological diversity — case study Vranica Mts in the Central Bosnia

Biologia ◽  
2007 ◽  
Vol 62 (2) ◽  
Author(s):  
Sulejman Redžić
Keyword(s):  
Plant Communities ◽  
Bosnia And Herzegovina ◽  
Carrying Capacity ◽  
General Level ◽  
Mountain Range ◽  
Ecological Diversity ◽  
Vegetation Diversity ◽  
High Level ◽  
Very High

AbstractSyntaxonomic diversity (SD) represents the number of plant communities (phytocoenoses) in certain area. Plant communities as organized systems of populations of various coexisting plant species inhabiting same or similar habitat in the function of time. SD is one of the best indicators of the state and potential carrying capacity of every ecosystem and an attribute of total ecological diversity. In general, level of syntaxonomic diversity indicates habitat heterogeneity and diversity. This could have significant importance in the categorization of habitat values in accordance with European Nature Information System (EUNIS) criteria. The results presented in this paper indicate without any doubt high natural values of mountain range Vranica in Bosnia and Herzegovina. One of the best proofs is an extremely high level of syntaxonomic diversity. In this area covering just 288 km2, vegetation is differentiated into 9 formations, 28 classes, 44 orders, 73 alliances and 165 associations. This represents 85% of all classes, 73% of all orders, 65% of all alliances, and 53% of all associations of vegetation in Bosnia and Herzegovina, or 35% of all classes in vegetation diversity in Europe. Going from the level of class to the level of order, the number of syntaxa increases for 61%, from order to alliance for 60%, and from alliance to association for 44.24% (average 55%). SD index is very high and it is 0.5729. This means that on each km2 contains 0.5729 syntaxa.

Vegetation diversity of the two Dinaric karstic rivers in Bosnia and Herzegovina

Biologia ◽  
2016 ◽  
Vol 71 (7) ◽  
Author(s):  
Anđelka Lasić ◽  
Nenad Jasprica
Keyword(s):  
Plant Communities ◽  
Bosnia And Herzegovina ◽  
Vegetation Diversity ◽  
Plant Associations ◽  
Phytosociological Relevés

AbstractPlant communities were studied along two oligotrophic karstic rivers – Trebižat and Lištica – from 2007 to 2009. Based on 93 phytosociological relevés, using Braun–Blanquet methods, a total of 25 plant associations were recognised in the rivers and nearby surveyed area. These associations have been subordinated to 11 alliances, eight orders and six classes:

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