scholarly journals Allelopathic tension of biotopes in forest ecosystems of wet subtropics

2021 ◽  
pp. 95-106
Author(s):  
V.G. Scherbina ◽  
Keyword(s):  
Synergistic Effect ◽  
Tree Species ◽  
Native Species ◽  
Forest Ecosystems ◽  
Soil Mass ◽  
Antagonistic Effect ◽  
Water Soluble ◽  
Black Sea Region ◽  
Adventive Species ◽  
Species Completeness

In the absence of a pronounced anthropogenic impact, allelopathic tension in forest ecosystems of the main formations of the Sochi Black Sea region and its influence on the saturation of phytocenoses with an adventive plant group are analyzed. The studies were carried out in 38 forest ecosystems of 7 formations at 13 stationary sites in the foothill zone. The absence of anthropogenic load was determined by the average bulk soil mass and the class of atmospheric air pollution. The аllelopathy environment of individual trees was assessed according to the activity of the forest floor of 21 tree species recorded in the analyzed forest communities. The tension of biotopes in ecosystems was assessed with the joint growth of 1 to 5 tree species in the main canopy. The activity of water-soluble colins was determined by biotesting of water extracts from forest litter according to A.M. Grodzinsky. The activity of the solutions was assessed by the index of allelopathic activity. It is shown that the magnitude of the contribution of the influence of phytocenosis to the allelopathic background of the biotope depends on the species-specific features of the stand and the manifestation of a synergistic or antagonistic effect of аllelopathy related to the level of species completeness of communities. An increase in species completeness to 0,4-0,6 is accompanied by an increase in the synergistic effect, a decrease in the intensity of the аllelopathic background and saturation with adventive species, with their proportion increasing by 11,9-21,5%. An increase in the species completeness by more than 0, 6 is statistically reliably accompanied by a decrease in the synergistic effect and a transition to antagonism, with an increase in allelopathic tension in the community, increasing the proportion of native species, reducing the number of free niches for adventive species and the level of vulnerability of communities to their introduction and distribution.

scholarly journals Long-Term Effects of Forest Plantation Species on Chemical Soil Properties in Southern Rwanda

Soil Systems ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 59
Author(s):  
Peter Rwibasira ◽  
Francois Xavier Naramabuye ◽  
Donat Nsabimana ◽  
Monique Carnol
Keyword(s):  
Soil Properties ◽  
Tree Species ◽  
Native Species ◽  
Water Soluble ◽  
Hot Water ◽  
Eucalyptus Species ◽  
Long Term Effects ◽  
Soil Functioning ◽  
C And N

Understanding the long-term effects of tree species on soil properties is crucial for the development of forest restoration policies in relation to the choice of species that meet both environmental and local livelihood needs. This study was performed in the Arboretum of Ruhande, Southern Rwanda, where monocultures of 148 deciduous and 56 conifer species have been established in 0.25 ha replicated plots from 1933 onwards. We investigated the effects of six exotic and two native tree species planted in monoculture plots and native species mixed within one self-regenerated plot on soil properties in two layers (0–5 cm and 5–10 cm depth). We measured general soil properties (pH, SOM, exchangeable base cations) and water-soluble C and N as a proxy for soil functioning. Changes in soil properties were observed in the upper soil layer for all tree species. Planting Eucalyptus species caused soil acidification, whereas soil exchangeable cations and pH were higher under native species (Entandrophragma excelsum and Polyschias fulva) and mixed native species. The effects of tree species were more pronounced for hot water-extractable C and N than for other soil properties. Their analyses could be used for detecting changes in soil functioning linked to vegetation types.

scholarly journals Springtail community structure is influenced by functional traits but not biogeographic origin of leaf litter in soils of novel forest ecosystems

2018 ◽  
Vol 285 (1879) ◽  
pp. 20180647 ◽  
Author(s):  
Laura J. Raymond-Léonard ◽  
Dominique Gravel ◽  
Peter B. Reich ◽  
I. Tanya Handa
Keyword(s):  
Community Structure ◽  
Leaf Litter ◽  
Tree Species ◽  
Native Species ◽  
Forest Ecosystems ◽  
Food Resource ◽  
Biotic Interactions ◽  
Functional Trait ◽  
Tree Communities ◽  
Springtail Community

With ongoing global change, shifts in the ranges of non-native species and resulting novel communities can modify biotic interactions and ecosystem processes. We hypothesized that traits and not biogeographic origin of novel plant communities will determine community structure of organisms that depend on plants for habitat or as a food resource. We tested the functional redundancy of novel tree communities by verifying if six pairs of congeneric European and North American tree species bearing similar leaf litter traits resulted in similar ecological filters influencing the assembly of springtail (Collembola) communities at two sites. Litter biogeographic origin (native versus non-native) did not influence springtail community structure, but litter genus, which generally reflected trait differences, did. Our empirical evidence suggests that a functional trait approach may be indeed as relevant as, and complementary to, studying biogeographic origin to understand the ecological consequences of non-native tree species in soils of novel forest ecosystems.

scholarly journals Response of Chinese Tallow (Triadica sebifera) and Coexisting Natives to Competition, Shade, and Flooding

2021 ◽  
Author(s):  
Olaniyi O Ajala ◽  
Kathryn R Kidd ◽  
Brian P Oswald ◽  
Yuhui Weng ◽  
Jeremy P Stovall
Keyword(s):  
Tree Species ◽  
Native Species ◽  
High Irradiance ◽  
Total Biomass ◽  
Green Ash ◽  
Lower Growth ◽  
Triadica Sebifera ◽  
Chinese Tallow ◽  
Growth Metrics ◽  
Water Tupelo

Abstract A greenhouse experiment was designed to determine the interactive effect of light, flooding, and competition on the growth and performance of Chinese tallow (Triadica sebifera [L.] Roxb.) and three tree species native to the southeastern United States: water tupelo (Nyssa aquatica L.), sugarberry (Celtis occidentalis L.), and green ash (Fraxinus pennsylvanica Marshall). The experiment used a factorial design that received two treatments: light (low irradiance or high irradiance) and flood (nonflooded and flooded) regimes. In the nonflooded and high irradiance treatment, changes in the growth (ground diameter, number of leaves, and total biomass) indicated that growth metrics of tallow were highest when growing with sugarberry and water tupelo but decreased when tallow was in competition with green ash. In contrast, competition with tallow reduced the height, net photosynthetic rate, stomatal conductance, and transpiration rate of water tupelo. The results showed that tallow had lower growth metrics when in competition with green ash at no apparent decrease in the growth of green ash except for growth rate. Our results suggest that tallow may be less competitive with certain native species and underplanting may be a possible opportunity for improving the success rates of native trees species establishment in areas prone to tallow invasion. Study Implications: Chinese tallow is a highly invasive tree species in the southeastern coastal states and in this study, we examined the growth and survival of tallow in competition with tree species native to the southeastern coastal states, USA. The growth of tallow differed greatly among native species in well-drained environments lacking forest overstory with lower growth metrics when grown with green ash but higher growth metrics when grown with water tupelo and sugarberry. Following density reduction treatments, we recommend management actions that promote the regeneration of native tree species to occupy the open vegetation canopy and suppress reestablishment of tallow.

scholarly journals Exotic urban trees conserve similar natural enemy communities to native congeners but have fewer pests

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6531 ◽  
Author(s):  
Steven D. Frank ◽  
Kristi M. Backe ◽  
Casey McDaniel ◽  
Matthew Green ◽  
Sarah Widney ◽  
...  
Keyword(s):  
Natural Enemies ◽  
Tree Species ◽  
Native Species ◽  
Urban Trees ◽  
Scale Insects ◽  
Single Family ◽  
Exotic Trees ◽  
Exotic Tree ◽  
Native Tree Species ◽  
Arthropod Pest

Urban trees serve a critical conservation function by supporting arthropod and vertebrate communities but are often subject to arthropod pest infestations. Native trees are thought to support richer arthropod communities than exotic trees but may also be more susceptible to herbivorous pests. Exotic trees may be less susceptible to herbivores but provide less conservation value as a consequence. We tested the hypotheses that native species in Acer and Quercus would have more herbivorous pests than exotic congeners and different communities of arthropod natural enemies. The density of scale insects, common urban tree pests, was greatest on a native Acer and a native Quercus than exotic congeners in both years of our research (2012 and 2016) and sometimes reached damaging levels. However, differences in predator and parasitoid abundance, diversity, and communities were not consistent between native and exotic species in either genus and were generally similar. For example, in 2012 neither predator nor parasitoid abundance differed among native and exotic Acer congeners but in 2016 a native species, A. saccharum, had the least of both groups. A native, Q. phellos, had significantly more predators and parasitoids in 2012 than its native and exotic congeners but no differences in 2016. Parasitoid communities were significantly different among Acer species and Quercus species due in each case to greater abundance of a single family on one native tree species. These native and exotic tree species could help conserve arthropod natural enemies and achieve pest management goals.

scholarly journals Assessment of adaptive capacity of native and adventive species of trees and shrubs in Dnipro region

2021 ◽  
Vol 50 ◽  
pp. 12-21
Author(s):  
I. A. Ivanko ◽  
A. F. Kulik
Keyword(s):  
Invasive Species ◽  
Peroxidase Activity ◽  
Tree Species ◽  
Native Species ◽  
Steppe Zone ◽  
Morus Alba ◽  
Acer Platanoides ◽  
Ulmus Pumila ◽  
Acer Negundo ◽  
Ulmus Laevis

Nowadays, deterioration and loss of ecological functions of urban tree and shrub plantations take place in Europe and, in particular, in Ukraine; it was noted that their number is insufficient to counteract the negative impact of global climate change and protect the population against industrial pollution effects. The issue of resistance of native and adventitious tree species used in the plantations of industrial cities remains relevant; it necessitates the assessment of physiological and biochemical aspects of their adaptation to extreme environmental factors, such as moisture limit in the steppe zone, periodic dangerously low winter temperatures and anthropo-technogenic load (in large urban agglomerations). In order to optimize the assortment of tree species of large megalopolises of the steppe zone of Ukraine and determine their potential resistance to anthropogenic pressures the study was conducted in conditionally clean forest biogeocenoses of the Samara River levee zone and in artificial plantations on the territories located in the coastal zone of the Dnipro River within 1500 m from the Prydneprovskaya thermal electric station (PTES, Dnipro city). It well known that the TPP is the source of atmospheric air pollution by such heavy metals as lead and cadmium. A study of the activity of antioxidant protection enzymes in leaves of native and adventive tree species showed that in the zone of Prydneprovskaya TES impact there was an increase of guaiacol peroxidase activity in Acer platanoides, Ulmus minor, Morus alba; benzidine peroxidase in Acer negundo, Ulmus laevis, Acer platanoides; catalase in A. platanoides, A. negundo, U. laevis, Ulmus pumila and Robinia pseudoasasia. High peroxidase activity, which is complemented by higher catalase activity, indicates the relative resistance of these species to atropo-technogenic pressures supported by antioxidant defense mechanisms. Total chlorophyll content (Chla + Chlb) in leaves of native species Ulmus laevis, Acer platanoides and adventive Morus alba decreased in the zone of TPP impact in relation to conditionally clean areas. The ratio of chlorophyll a to chlorophyll b in contaminated areas significantly increased in leaves of native species Ulmus laevis, Ulmus minor, Acer platanoides compared with control. The invasive species Acer negundo, Morus alba, Ulmus pumila had no significant changes in this indicator. In invasive species such as Ulmus pumila, Acer negundo there was an increase in leaf mass, which may indicate adaptation of these species to anthropogenically altered growth conditions.

scholarly journals A water-soluble boronic acid sensor for caffeic acid based on double sites recognition

RSC Advances ◽  
2020 ◽  
Vol 10 (47) ◽  
pp. 28148-28156
Author(s):  
Zhancun Bian ◽  
Guiqian Fang ◽  
Ran Wang ◽  
Dongxue Zhan ◽  
Qingqiang Yao ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Caffeic Acid ◽  
Binding Affinity ◽  
Boronic Acid ◽  
Water Soluble ◽  
Specific Recognition ◽  
Recognition Sites

Herein, the specific recognition of caffeic acid by the double sites boronic acid sensor 5c is reported. The synergistic effect of the two recognition sites greatly improves the binding affinity and selectivity of the sensor.

scholarly journals Synergistic effect of water-soluble species and relative humidity on morphological changes in aerosol particles in the Beijing megacity during severe pollution episodes

2019 ◽  
Vol 19 (1) ◽  
pp. 219-232 ◽  
Author(s):  
Xiaole Pan ◽  
Baozhu Ge ◽  
Zhe Wang ◽  
Yu Tian ◽  
Hang Liu ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Synergistic Effect ◽  
Mineral Dust ◽  
Water Soluble ◽  
Dust Particles ◽  
Urban Site ◽  
Chemical Compositions ◽  
Aerodynamic Diameter ◽  
Soluble Species ◽  
Pollution Episodes

Abstract. Depolarization ratio (δ) of backscattered light is an applicable parameter for distinguishing the sphericity of particles in real time, which has been widely adopted by ground-based lidar observation systems. In this study, δ values of particles and chemical compositions in both PM2.5 (aerodynamic diameter less than 2.5 µm) and PM10 (aerodynamic diameter less than 10 µm) were concurrently measured on the basis of a bench-top optical particle counter with a polarization detection module (POPC) and a continuous dichotomous aerosol chemical speciation analyzer (ACSA-14) from November 2016 to February 2017 at an urban site in Beijing megacity. In general, measured δ values depended on both size and sphericity of the particles. During the observation period, mass concentrations of NO3- in PM2.5 (fNO3) were about an order of magnitude higher than that in PM2.5−10 (cNO3) with a mean fNO3∕cNO3 ratio of 14±10. A relatively low fNO3∕cNO3 ratio (∼5) was also observed under higher relative humidity conditions, mostly due to heterogeneous processes and particles in the coarse mode. We found that δ values of ambient particles in both PM2.5 and PM2.5−10 obviously decreased as mass concentration of water-soluble species increased at unfavorable meteorological conditions. This indicated that the morphology of particles was changed as a result of water-absorbing processes. The particles with optical size (Dp) of Dp = 5 µm were used to represent mineral dust particles, and its δ values (δDp=5) decreased by 50 % as the mass fraction of cNO3 increased from 2 % to 8 % and ambient relative humidity increased up to 80 %, suggesting that mineral dust particles were likely to be spherical during humid pollution episodes. During the observation, relative humidity inside the POPC measuring chamber was stable at 34±2 %, lower than the ambient condition. Its influence on the morphology was estimated to be limited and did not change our major conclusion. This study highlights the evident alteration of non-sphericity of mineral dust particles during their transport owing to a synergistic effect of both pollutant coatings and hygroscopic processes, which plays an important role in the evaluation of its environmental effect.

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