scholarly journals A Survey in Natural Forest Ecosystems of Vietnam Reveals High Diversity of both New and Described Phytophthora Taxa including P. ramorum

Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 93 ◽  
Author(s):  
Thomas Jung ◽  
Bruno Scanu ◽  
Clive Brasier ◽  
Joan Webber ◽  
Ivan Milenković ◽  
...  

In 2016 and 2017, surveys of Phytophthora diversity were performed in 25 natural and semi-natural forest stands and 16 rivers in temperate and subtropical montane and tropical lowland regions of Vietnam. Using baiting assays from soil samples and rivers and direct isolations from naturally fallen leaves, 13 described species, five informally designated taxa and 21 previously unknown taxa of Phytophthora were isolated from 58 of the 91 soil samples (63.7%) taken from the rhizosphere of 52 of the 64 woody plant species sampled (81.3%) in 20 forest stands (83.7%), and from all rivers: P. capensis, P. citricola VII, VIII, IX, X and XI, P. sp. botryosa-like 2, P. sp. meadii-like 1 and 2, P. sp. tropicalis-like 2 and P. sp. multivesiculata-like 1 from Phytophthora major phylogenetic Clade 2; P. castaneae and P. heveae from Clade 5; P. chlamydospora, P. gregata, P. sp. bitahaiensis-like and P. sp. sylvatica-like 1, 2 and 3 from Clade 6; P. cinnamomi (Pc), P. parvispora, P. attenuata, P. sp. attenuata-like 1, 2 and 3 and P. ×heterohybrida from Clade 7; P. drechsleri, P. pseudocryptogea, P. ramorum (Pr) and P. sp. kelmania from Clade 8, P. macrochlamydospora, P. sp. ×insolita-like, P. sp. ×kunnunara-like, P. sp. ×virginiana-like s.l. and three new taxa, P. sp. quininea-like, P. sp. ×Grenada 3-like and P. sp. ×Peru 4-like, from Clade 9; and P. sp. gallica-like 1 and 2 from Clade 10. The A1 and A2 mating types of both Pc and Pr co-occurred. The A2 mating type of Pc was associated with severe dieback of montane forests in northern Vietnam. Most other Phytophthora species, including Pr, were not associated with obvious disease symptoms. It is concluded that (1) Vietnam is within the center of origin of most Phytophthora taxa found including Pc and Pr, and (2) Phytophthora clades 2, 5, 6, 7, 8, 9, and 10 are native to Indochina.

Plant Disease ◽  
2001 ◽  
Vol 85 (10) ◽  
pp. 1120-1120 ◽  
Author(s):  
D. Valiunas ◽  
A. Alminaite ◽  
J. Staniulis ◽  
R. Jomantiene ◽  
R. E. Davis

Alnus glutinosa (alder) is widespread in Europe and is an important component of biological diversity in natural forest ecosystems in the Baltic Region. In 2000, diseased trees of A. glutinosa exhibiting characteristically phytoplasmal disease symptoms of shoot proliferation and leaf yellowing were observed in Aukstaitija National Park, Lithuania. In other parts of Europe, alder is affected by a phytoplasmal disease known as alder yellows, which is characterized by symptoms that include yellowing and reduced leaf size, die-back of branches, and decline of trees (2,3). Proliferation of shoots has not been previously reported with this disease. An association between alder yellows and infection by a phytoplasma has been reported in A. glutinosa in Germany and Italy, and a phytoplasma has been found in A. glutinosa in France and Hungary (2,4). We examined symptomatic alder from Lithuania using nested polymerase chain reaction (PCR) (1), primed by P1/P7 and followed by R16F2n/R16R2 (F2n/R2), for amplification of phytoplasmal ribosomal (r) DNA. The results indicated the presence of a phytoplasma, designated ALY-L, in the diseased alder. We classified the ALY-L phytoplasma through restriction fragment length polymorphism (RFLP) analysis of 16S rDNA. A 1.2-kbp fragment (F2n-R2 segment) of rDNA, amplified in PCR primed by F2n/R2, was analyzed using single endonuclease enzyme digestion with AluI, MseI, KpnI, HhaI, HaeIII, HpaI, HpaII, RsaI, HinfI, TaqI, Sau3AI, BfaI, and ThaI. On the basis of collective RFLP patterns, phytoplasma ALY-L was classified as a member of group 16SrV (group V, elm yellows group), subgroup C. The amplified 16S rDNA was cloned in Escherichia coli and sequenced, and the sequence was deposited in the GenBank data library (Accession No. AY028789). Nucleotide sequence alignment revealed that 16S rDNA from phytoplasma ALY-L shared 100% sequence similarity with 16S rDNA (GenBank Accession No. Y16387) from a phytoplasma associated with alder yellows (ALY) disease in Italy. The results support the conclusion that a strain of ALY phytoplasma is present in Lithuania. Phytoplasmas belonging to groups 16SrI (aster yellows phytoplasma group) and III (X-disease phytoplasma group) have been found in herbaceous plant species in Lithuania. This report records the first finding of a group V phytoplasma, and the first finding of a phytoplasma in a tree species in the eastern Baltic Region. These findings contribute knowledge about the diversity of phytoplasmas in the Baltic Region and the distribution of ALY phytoplasma in Europe. Apparently, A. glutinosa may be infected by the phytoplasma but not develop obvious disease symptoms, as has been reported elsewhere (3). Thus, it is possible that ALY-L phytoplasma is widespread, but as yet undetected, throughout the geographic range of alder in the Baltic Region. This possibility is supported by the finding of the monophagous leafhopper vector (Oncopsis alni) of ALY phytoplasma throughout Europe (cited in Maixner and Reinert [3]). Further research is needed to assess the impact of phytoplasmal infections such as those by ALY-related phytoplasma strains on trends in biological diversity in the natural forest ecosystems of the Baltic Region and elsewhere in Europe. References: (1) R. Jomantiene et al. Int. J. Syst. Bacteriol. 48:269, 1998. (2) W. Lederer and E. Seemüller. Eur. J. For. Pathol. 21:90, 1991. (3) M. Maixner and W. Reinert. Eur. J. Plant Pathol. 105:87, 1999. (4) R. Mäurer et al. Phytopathology 83:971, 1993.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Edi Rustadi Setiadharma ◽  
Burhanuddin Burhanuddin ◽  
M Sofwan Anwari

This study aims to examine the composition and structure of the vegetation in the protected forest area of PT Finnantara Intiga's Sintang block and determine the pattern of forest restoration and the types of vegetation that will be used for restoration of degraded forests. This research was conducted at PT Finnantara Intiga Sintang Block which is located in five land cover areas, of which three are reference secondary swamp forest (KPPN, KPSL and river border) and two areas are degraded forest (shrub and open land). This study uses a survey method with a line plot system. The sample was determined by means of purposive sampling. Based on the results of research data analysis, the number of species found at all levels at the KPSL location was nine species, at the KPPN location there were eleven species, at the River Border location there were eight species, at the Semak Belukar location there were seven species and at the Open Land location there were four species. In general, the horizontal structure of forest stands in damaged forest ecosystems is below the horizontal structure of natural forest stands as a reference. This shows that the level of vegetation density at the location of shrubs and open land has decreased so that forest restoration measures are needed to increase the density closer to natural forest ecosystems that have not been damaged. The pattern of forest restoration for scrub areas and open land referring to the Guidelines for Restoration in Conservation Areas (JICA, 2014) is natural succession. The pattern of forest restoration that will be implemented must take into account the physical conditions of the field and local socio-cultural considerations based on stakeholder considerations. The type of vegetation for enrichment and planting activities at the shrub location refers to the KPSL location as a reference because it tends to have similarities with the community similarity index of 52.03%. The type of vegetation for enrichment and planting activities on open land locations refers to the KPPN location as a reference because it tends to have similarities with the community similarity index of 52.17%. Keywords:  Composition, forest degradation, restoration, structureAbstrakPenelitian ini bertujuan untuk mengkaji komposisi dan struktur vegetasi di kawasan hutan perlindungan blok Sintang PT Finnantara Intiga serta menentukan pola pemulihan hutan dan jenis vegetasi yang akan digunakan untuk restorasi hutan terdegradasi. Penelitian ini dilaksanakan di PT Finnantara Intiga Blok Sintang yang terletak di lima areal tutupan lahan, dimana tiga areal sebagai hutan rawa sekunder referensi (KPPN, KPSL dan sempadan sungai) dan dua areal di hutan yang terdegradasi (semak belukar dan lahan terbuka). Penelitian ini menggunakan metode survey dengan cara jalur berpetak. Sampel ditentukan dengan cara Purposive Sampling. Berdasarkan hasil analisis data penelitian, Jumlah jenis yang ditemui di semua tingkatan di lokasi KPSL ada sembilan jenis, dilokasi KPPN ada sebelas jenis, di lokasi Sempadan Sungai ada delapan jenis, di lokasi Semak Belukar ada tujuh jenis dan di lokasi Lahan Terbuka ada empat jenis. Secara umum bentuk grafik struktur horizontal tegakan hutan pada ekosistem hutan yang mengalami kerusakan berada di bawah grafik struktur horizontal tegakan hutan alam yang menjadi referensi. Hal ini menunjukkan bahwa tingkat kerapatan vegetasi pada lokasi semak belukar dan lahan terbuka mengalami penurunan sehingga diperlukan tindakan pemulihan hutan untuk meningkatkan kerapatan mendekati ekosistem hutan alam yang belum mengalami kerusakan. Pola pemulihan hutan untuk areal semak belukar dan lahan terbuka merujuk pada Pedoman Tata Cara Restorasi di Kawasan Konservasi (JICA, 2014) adalah suksesi alami. Pola pemulihan hutan yang akan dilaksanakan harus mempertimbangkan kondisi fisik lapangan dan sosial budaya setempat berdasarkan pertimbangan stakeholder. Jenis vegetasi untuk kegiatan pengkayaan dan penanaman pada lokasi semak belukar mengacu pada lokasi KPSL sebagai referensi karena kecenderungan memiliki kemiripan dengan dengan indeks kesamaan komunitas sebesar 52,03%. Jenis vegetasi untuk kegiatan pengkayaan dan penanaman pada lokasi lahan terbuka mengacu pada lokasi KPPN sebagai referensi karena kecenderungan memiliki kemiripan dengan dengan indeks kesamaan komunitas sebesar 52,17%.Kata kunci: Degradasi hutan, komposisi, restorasi, struktur


2012 ◽  
Vol 49 (No. 5) ◽  
pp. 208-219 ◽  
Author(s):  
P. Mückstein ◽  
O. Holuša

In 1999–2000 in the Protected Landscape Area (PLA) Žďárské vrchy hills the occurrence of psocids (Psocoptera) was studied in different types of biotopes: natural forest ecosystems (stands of Fagus sylvatica with individual admixture of Abies alba, Acer pseudoplatanus, Picea abies), changed forest ecosystems (monoculture of Picea abies), young plantations in forest stands, disperse forest vegetation (solitary trees), and also non-forest ecosystems – agrocenoses, meadows and grazing lands. A total of 10,560 adults in 20 species were found. Three groups of biotopes with specific psocid taxocenosis were found out by computed cluster analysis – l. natural forest stands with dominance of Fagus sylvatica, 2. disperse tree vegetation and solitary trees in cultural landscape, and 3. forest stands remote to nature (monoculture of Picea abies). Occurrence of psocids was observed from the beginning of May to mid- November. Maximum of abundance was found in September.


Author(s):  
Otakar Holuša

In the Oravské Beskydy Mts. in the National Natural Reserves of Babia hora Mt. and Pilsko Mt. (northern Slovakia) are natural forest and near-natural forest stands in 8th (Piceeta s. lat. =Spruce) and in 9th (Pineta mugo s. lat. = dwarf pine) vegetation tiers (= altitudinal vegetation zones) (vegetation tiers according Plíva 1971, 1991, Holuša and Holuša 2008, 2010, 2011). During 1999–2000, psocids (Psocoptera) were studied from 6th to 9th vegetation tiers. In total, 1,113 adults and 42 larvae in 17 species were found. In 6th VT, 11 species were found (the following species were eudominant: Caecilius burmeisteri, Philotarsus picicornis and Caecilius flavidus), in 7th VT only 4 species (eudominant Philotarsus picicornis, Caecilius despaxi and Philotarsus picicornis), in 8th VT 10 species (eudominant Stenopsocus lachlani, Caecilius despaxi and C. burmeisteri) and in 9th VT 10 species (eudominant Caecilius burmeisteri, Lachesilla pedicularia and Stenopsocus lachlani). Taxocenoses of psocids in the Oravské Beskydy Mts. were evaluated by Detrend Corespondence analysis (DCA) and Divisive Cluster analysis (DvClA). Material was compared with other material from various vegetation tiers in the Western Carpathians Mts. Characteristic species combination of psocids of 9th VT was designated as follows: Lachesilla pedicularia – Caecilius despaxi – Stenopsocus lachlani.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shamsollah Ayoubi ◽  
Nafiseh Sadeghi ◽  
Farideh Abbaszadeh Afshar ◽  
Mohammad Reza Abdi ◽  
Mojtaba Zeraatpisheh ◽  
...  

Abstract Background As one of the main components of land-use change, deforestation is considered the greatest threat to global environmental diversity with possible irreversible environmental consequences. Specifically, one example could be the impacts of land-use changes from oak forests into agricultural ecosystems, which may have detrimental impacts on soil mobilization across hillslopes. However, to date, scarce studies are assessing these impacts at different slope positions and soil depths, shedding light on key geomorphological processes. Methods In this research, the Caesium-137 (137Cs) technique was applied to evaluate soil redistribution and soil erosion rates due to the effects of these above-mentioned land-use changes. To achieve this goal, we select a representative area in the Lordegan district, central Iran. 137Cs depth distribution profiles were established in four different hillslope positions after converting natural oak forests to rainfed farming. In each hillslope, soil samples from three depths (0–10, 10–20, and 20–50 cm) and in four different slope positions (summit, shoulder, backslope, and footslope) were taken in three transects of about 20 m away from each other. The activity of 137Cs was determined in all the soil samples (72 soil samples) by a gamma spectrometer. In addition, some physicochemical properties and the magnetic susceptibility (MS) of soil samples were measured. Results Erosion rates reached 51.1 t·ha− 1·yr− 1 in rainfed farming, whereas in the natural forest, the erosion rate was 9.3 t·ha− 1·yr− 1. Magnetic susceptibility was considerably lower in the cultivated land (χhf = 43.5 × 10− 8 m3·kg− 1) than in the natural forest (χhf = 55.1 × 10− 8 m3·kg− 1). The lower soil erosion rate in the natural forest land indicated significantly higher MS in all landform positions except at the summit one, compared to that in the rainfed farming land. The shoulder and summit positions were the most erodible hillslope positions in the natural forest and rainfed farming, respectively. Conclusions We concluded that land-use change and hillslope positions played a key role in eroding the surface soils in this area. Moreover, land management can influence soil erosion intensity and may both mitigate and amplify soil loss.


2020 ◽  
Vol 5 (4) ◽  
pp. 153-162
Author(s):  
Mohammed Adefa Seid ◽  
Yigardu Mulatu ◽  
Agena Anjulo ◽  
Semaigzer Ayalew ◽  
Hailu Belay ◽  
...  

The population dynamics and genetic qualities of stem height and dbh of the populations of Milicia excelsa, Pouteria adolfi-fridercii, Antiaris toxicaria and Prunus africana were assessed and studied in 14 forest ecosystems in south and south-western Ethiopia. A systematic random quadrat sampling technique was employed to identify potential habitat area for selected timber species in south and south-western Ethiopia. So, a total of 10 parallel transect lines were set out across each forest habitat. Milicia excelsa was assessed in four forest ecosystems; Bebeka -Duduka natural forest (45 tree stem ha-1) and Yayu coffee mixed forest (40 tree stem ha-1) appeared to have relatively denser population of M. excelsa compared to the other pilot forests. Similarly, statistically larger stem height (m) is observed in Bebeka-Duduka natural forest (x̅=29.5, SD=4.2) and larger dbh size (cm) in Bebeka 1 coffee mixed forest (x̅=48.5, SD=25.2) at p<0.05. Hence, Bebeka-Duduka natural forest and Bebeka 1 coffee mixed forests are identified for in-situ SPA establishment project of the target species. Pouteria adolfi-fridercii was assessed in eight forest ecosystems; Masha-Gora shewi forest appeared to have dense population of P. adolfi-fridercii (150 tree stem ha-1) followed by Bebeka-Kebereta (80 tree stem ha-1) as compared to the remaining pilot forests. However, statistically larger stem height (m) is scored in Bebeka 2 natural forest (x̅=30.6, SD=2.98) and Bebeka-kebereta forest (x̅=30.0, SD=4.4) and larger dbh size (cm) in Bebeka 2 natural forest (x̅=96.5, SD=19.9) at p<0.05. So, Bebeka 2 natural forest and Bebeka-kebereta forest are identified for SPA establishment project of the target species. Antiaris toxicaria was assessed in two forest ecosystems where both forest habitats appeared to have the same density of Antiaris toxicaria in hectare. Moreover, analyses of mean stem height (cm) of Bebeka 1 forest (x̅=21.4, SD=5.2) and Bebeka-kebereta forest (x̅=22.4, SD=2.7), and mean dbh size (cm) of Bebeka 1 forest (x̅=48, SD=16.4) and Bebeka-kebereta forest (x̅=48, SD=8.2) appeared to have not significantly different at p<0.05. Prunus africana was assessed in five forest ecosystems; Masha-Gora shewi forest appeared to have dense population of Prunus africana (150 tree stem ha-1) followed by Kaho-shemeta forest (130 tree stem ha-1) as compared to the remaining pilot forests. However, statistically larger stem height (m) is scored in Kaho-shemeta natural forest (x̅=31, SD=7.6) and larger dbh (cm) in Masha-Gora shewi forest (x̅=64.7, SD=28.2) at p<0.05. As the result, Kaho-shemeta natural forest and Bonga-Teja-adela forest are identified for establishment of seed production area of the target species in-situ. Hence, while implementing the project of domestication and seed production area establishment in south and south-western Ethiopia, in-situ and ex-situ areas must be selected and delineated in accordance with this preliminary information of the population dynamics and genetic qualities of stem height and diameter at breast height. The survey data generated in this study would bridge the research gap in relation to the population status of the target tree species in the designated area.


Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 259 ◽  
Author(s):  
Thomas Jung ◽  
Federico La Spada ◽  
Antonella Pane ◽  
Francesco Aloi ◽  
Maria Evoli ◽  
...  

: The aim of this study was to investigate the occurrence, diversity, and distribution of Phytophthora species in Protected Natural Areas (PNAs), including forest stands, rivers, and riparian ecosystems, in Sicily (Italy), and assessing correlations with natural vegetation and host plants. Fifteen forest stands and 14 rivers in 10 Sicilian PNAs were studied. Phytophthora isolations from soil and stream water were performed using leaf baitings. Isolates were identified using both morphological characters and sequence analysis of the internal transcribed spacer (ITS) region. A rich community of 20 Phytophthora species from eight phylogenetic clades, including three new Phytophthora taxa, was recovered (17 species in rhizosphere soil from forest stands and 12 species in rivers). New knowledge about the distribution, host associations, and ecology of several Phytophthora species was provided.


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