scholarly journals No Ontogenetic Shifts in C-, N- and P-Allocation for Two Distinct Tree Species along Elevational Gradients in the Swiss Alps

Forests ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 394 ◽  
Author(s):  
Jian-Feng Liu ◽  
Ze-Ping Jiang ◽  
Marcus Schaub ◽  
Arthur Gessler ◽  
Yan-Yan Ni ◽  
...  
Keyword(s):  
Tree Species ◽  
Environmental Changes ◽  
Tissue Concentration ◽  
Swiss Alps ◽  
Tree Age ◽  
Nutrient Allocation ◽  
Mature Trees ◽  
Elevational Gradients ◽  
Alpine Treeline ◽  
Adult Trees

Most of our knowledge about forest responses to global environmental changes is based on experiments with seedlings/saplings grown in artificially controlled conditions. We do not know whether this knowledge will allow us to upscale to larger and mature trees growing in situ. In the present study, we used elevation as a proxy of various environmental factors, to examine whether there are ontogenetic differences in carbon and nutrient allocation of two major treeline species (Pinus cembra L. and Larix decidua Mill.) along elevational gradients (i.e., environmental gradient) in the Swiss alpine treeline ecotone (~300 m interval). Young and adult trees grown at the same elevation had similar levels of non-structural carbohydrates (NSCs), total nitrogen (TN), and phosphorus (TP), except for August leaf sugars and August leaf TP in P. cembra at the treeline. We did not detect any interaction between tree age and elevation on tissue concentration of NSCs, TN, and TP across leaf, shoot, and root tissues for both species, indicating that saplings and mature trees did not differ in their carbon and nutrient responses to elevation (i.e., no ontogenetic differences). With respect to carbon and nutrient allocation strategies, our results show that young and adult trees of both deciduous and evergreen tree species respond similarly to environmental changes, suggesting that knowledge gained from controlled experiments with saplings can be upscaled to adult trees, at least if the light is not limited. This finding advances our understanding of plants’ adaptation strategies and has considerable implications for future model-developments.

scholarly journals COMMUNITY STRUCTURE AND REGENERATION STATUS OF TREE SPECIES IN KYONGNOSLA ALPINE SANCTUARY, EASTERN HIMALAYA, INDIA

2021 ◽  
Vol 8 (2) ◽  
pp. 241-257
Author(s):  
Subhajit Lahiri ◽  
Sudhansu Sekhar Dash
Keyword(s):  
Tree Species ◽  
Mixed Forest ◽  
Basal Area ◽  
Habitat Destruction ◽  
Eastern Himalaya ◽  
Diameter Distribution ◽  
Mature Trees ◽  
Regeneration Status ◽  
Adult Trees ◽  
Over Exploitation

Habitat destruction, over exploitation, monoculture are major reasons for loss of primary forests in Himalaya. Tree population, composition and diversity particularly in the temperate Himalaya play a key role in the maintenance of many ecosystem services and natural biogeochemical cycles. The present study explores composition and regeneration status of tree species in a temperate mixed forest in Kyongnosla Alpine Sanctuary, East Sikkim, India.  Two sites at an elevation range of 2800–3800 m were selected and 20 plots of 20 m × 20 m for trees, 80 plots of 5 m × 5 m for saplings, and 160 plots of 1 m × 1 m for seedlings were sampled to study the regeneration status. A total of 17 tree species belonging to 9 genera and 8 families were recorded of which Rhododendron was the most dominant genus with maximum number of species. All the phytosociological attributes, such as relative density, abundance and important value index were calculated. The average species richness of adult trees and saplings was 13.5± 0.7 and for seedlings it was 12.5 ± 0.07. The mean density of seedlings was 3609.77 ± 494.39 individuals/ ha, for saplings  1540 ± 113.13 individuals/ha and of mature trees  548.75 ± 8.83 individuals/ha. Total basal area cover ranged from 36.61 to 40.35 m2/ha for trees, from 1.54 to 1.71 m2/ha for saplings.  Fair regeneration was observed in 64.72% of total species; good regeneration observed in 17.64% species, 11.76 % species exhibited poor regeneration while 5.88% showed no regeneration.  Density-diameter distribution exhibited decrease in tree densities towards higher DBH classes. The study not only provides reliable information on the ecosystem’s health of the sanctuary but also will help in understanding the complexity of the ecosystem function and an approach to conservation of biota.

scholarly journals El Niño-Southern Oscillation affects the water relations of tree species in the Yucatan Peninsula, Mexico

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jorge Palomo-Kumul ◽  
Mirna Valdez-Hernández ◽  
Gerald A. Islebe ◽  
Manuel J. Cach-Pérez ◽  
José Luis Andrade
Keyword(s):  
Water Potential ◽  
Leaf Area ◽  
Tropical Forests ◽  
Specific Leaf Area ◽  
Tree Species ◽  
Deciduous Species ◽  
Mature Trees ◽  
Seasonally Dry ◽  
Seasonally Dry Tropical Forests ◽  
Dry Tropical Forests

AbstractWe evaluated the effect of ENSO 2015/16 on the water relations of eight tree species in seasonally dry tropical forests of the Yucatan Peninsula, Mexico. The functional traits: wood density, relative water content in wood, xylem water potential and specific leaf area were recorded during the rainy season and compared in three consecutive years: 2015 (pre-ENSO conditions), 2016 (ENSO conditions) and 2017 (post-ENSO conditions). We analyzed tree size on the capacity to respond to water deficit, considering young and mature trees, and if this response is distinctive in species with different leaf patterns in seasonally dry tropical forests distributed along a precipitation gradient (700–1200 mm year−1). These traits showed a strong decrease in all species in response to water stress in 2016, mainly in the driest site. Deciduous species had lower wood density, higher predawn water potential and higher specific leaf area than evergreen species. In all cases, mature trees were more tolerant to drought. In the driest site, there was a significant reduction in water status, regardless of their leaf phenology, indicating that seasonally dry tropical forests are highly vulnerable to ENSO. Vulnerability of deciduous species is intensified in the driest areas and in the youngest trees.

Tree-Ring Formation, Radial Increment Periodicity, and Phenology of Tree Species from a Seasonal Semi-Deciduous Forest in Southeast Brazil

IAWA Journal ◽  
2008 ◽  
Vol 29 (2) ◽  
pp. 189-207 ◽  
Author(s):  
Claudio S. Lisi ◽  
Mário Tomazello Fo ◽  
Paulo C. Botosso ◽  
Fidel A. Roig ◽  
Vivian R.B. Maria ◽  
...  
Keyword(s):  
Tree Rings ◽  
Tree Species ◽  
Deciduous Forest ◽  
Growth Ring ◽  
Climatic Conditions ◽  
Dry Season ◽  
Tree Age ◽  
Radial Increment ◽  
Future Studies ◽  
Southeast Brazil

Many tropical tree species produce growth rings in response to seasonal environmental factors that influence the activity of the vascular cambium. We applied the following methods to analyze the annual nature of treering formation of 24 tree species from a seasonal semi-deciduous forest of southeast Brazil: describing wood anatomy and phenology, counting tree rings after cambium markings, and using permanent dendrometer bands. After 7 years of systematic observations and measurements, we found the following: the trees lost their leaves during the dry season and grew new leaves at the end of the same season; trunk increment dynamics corresponded to seasonal changes in precipitation, with higher increment (active period) during the rainy season (October–April) and lower increment (dormant period) during the dry season (May–September); the number of tree rings formed after injuries to the cambium coincided with the number of years since the extraction of the wood samples. As a result of these observations, it was concluded that most study trees formed one growth ring per year. This suggests that tree species from the seasonal semi-deciduous forests of Brazil have an annual cycle of wood formation. Therefore, these trees have potential for use in future studies of tree age and radial growth rates, as well as to infer ecological and regional climatic conditions. These future studies can provide important information for the management and conservation of these endangered forests.

5. Simple complex questions

2020 ◽  
pp. 73-93
Author(s):  
Jaboury Ghazoul
Keyword(s):  
Tropical Forest ◽  
Tree Species ◽  
Dominant Species ◽  
Environmental Changes ◽  
Top Down ◽  
Simple Complex ◽  
Bottom Up ◽  
Biological Richness

‘Simple complex questions’ contrasts top-down and bottom-up approaches to ecological puzzles. For example, plants evade herbivores with physical defences that render them toxic or unpalatable, and the predators then evolve their own defences. How can a tropical forest support over 1,000 different tree species in a 50-hectare plot? When trees in the same forest differ in their response to environmental changes, can we still describe their environment as a niche? In species-rich systems, is there stability in complexity? Do we need so many species? Even when answering this question, we might benefit from a less human-centred approach. Earth’s biological richness has resonance beyond the dominant species.

scholarly journals Positive biodiversity–productivity relationships in forests: climate matters

2018 ◽  
Vol 14 (4) ◽  
pp. 20170747 ◽  
Author(s):  
H. Jactel ◽  
E. S. Gritti ◽  
L. Drössler ◽  
D. I. Forrester ◽  
W. L. Mason ◽  
...  
Keyword(s):  
Climate Change ◽  
Carbon Sequestration ◽  
Tree Species ◽  
Climatic Factors ◽  
Meta Analysis ◽  
Global Scale ◽  
Tree Age ◽  
Drought Severity ◽  
Natural Forests ◽  
Mixed Species

While it is widely acknowledged that forest biodiversity contributes to climate change mitigation through improved carbon sequestration, conversely how climate affects tree species diversity–forest productivity relationships is still poorly understood. We combined the results of long-term experiments where forest mixtures and corresponding monocultures were compared on the same site to estimate the yield of mixed-species stands at a global scale, and its response to climatic factors. We found positive mixture effects on productivity using a meta-analysis of 126 case studies established at 60 sites spread across five continents. Overall, the productivity of mixed-species forests was 15% greater than the average of their component monocultures, and not statistically lower than the productivity of the best component monoculture. Productivity gains in mixed-species stands were not affected by tree age or stand species composition but significantly increased with local precipitation. The results should guide better use of tree species combinations in managed forests and suggest that increased drought severity under climate change might reduce the atmospheric carbon sequestration capacity of natural forests.

scholarly journals Species Association of the Dominant Tree Species in an Old-Growth Forest and Implications for Enrichment Planting for the Restoration of Natural Degraded Forest in Subtropical China

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 957 ◽  
Author(s):  
Liu ◽  
Zhu ◽  
Wang ◽  
Ma ◽  
Meng
Keyword(s):  
Tree Species ◽  
Rank Correlation ◽  
Economic Benefits ◽  
Natural Forests ◽  
Subtropical China ◽  
Old Growth ◽  
Species Association ◽  
Old Growth Forest ◽  
Enrichment Planting ◽  
Adult Trees

Subtropical natural forests are unique due to their ecological and economic functions. However, most of these forests are highly degraded, which impairs the ability to provide ecological and economic benefits. Enrichment planting is an important approach to restore natural degraded forests. Species arrangement is of great importance to inform enrichment planting. Species association refers to the interrelationship of different species occupying a habitat and is a static description of the organic connection formed by the interaction of species. Species association, therefore, provides a scientific basis for species arrangement in enrichment planting. Additionally, because an old-growth forest is a climax community that has attained great age without significant disturbance, the species association in an old-growth forest can provide valuable information on the reference conditions for forest management. In this study, the species association between dominant tree species (including saplings and adult trees) was investigated in an old-growth forest in the Gutianshan National Nature Reserve in Zhejiang province in subtropical China. The objective of the study was to inform species arrangement for enrichment planting. The result showed that the overall species association exhibited a significant net positive association, indicating a dynamic balance of stable structure and species composition in the old-growth forest. Additionally, the pairwise species association was examined using the χ2 test, the Dice index, and Spearman’s rank correlation coefficient; significant positive and negative pairwise species associations were detected. Based on the species association and the light requirements of the tree species, an optimal species arrangement was determined to support enrichment planting for restoring natural degraded forests. It is expected that the results of this study will contribute to the restoration of natural degraded forests in subtropical China.

Testing pathogen host specificity: a reciprocal field experiment in two types of tropical forest on Hainan, China

2013 ◽  
Vol 29 (6) ◽  
pp. 541-549 ◽  
Author(s):  
Wen Zheng ◽  
He He ◽  
Lin Xiao ◽  
Shixiao Yu
Keyword(s):  
Seed Germination ◽  
Host Specificity ◽  
Tree Species ◽  
Rain Forest ◽  
Forest Type ◽  
Seedling Survival ◽  
Cloud Forest ◽  
Soil Pathogens ◽  
Montane Rain Forest ◽  
Adult Trees

Abstract:The Janzen–Connell hypothesis suggests that highly specific pathogens decrease seedling survival close to the parent plant; however, the underlying mechanism remains unclear. Here, we tested the host specificity of soil pathogens to germinating seeds of Cyclobalanopsis fleuryi and Cryptocarya chinensis in tropical montane rain forest and cloud forest on Hainan, south China. Rhizospheric soils surrounding eight adult trees per species were collected in each forest type and divided into five soil treatments: parent, fungicide-sterilized, autoclave-sterilized, Fusarium-added and Pythium-added soils. Surface-sterilized seeds were sown in each of the five soil treatments and grown in two forest types. The seed germination percentages were significantly higher in sterilized soils (C. fleuryi, 41.5%; C. chinensis, 29.4%) than in non-sterilized soils (C. fleuryi, 28.3%; C. chinensis, 17.1%) in montane rain forest. The seed germination percentages in rhizospheric soil of conspecific parent trees were significantly lower in montane rain forest (C. fleuryi, 17.3%; C. chinensis, 10.5%) than in cloud forest (C. fleuryi, 37.1%; C. chinensis, 21.1%). Our results also suggest that the level of pathogen activity in each tree species varies depending on the environment. Our results support the hypothesis that host-specific pathogens shape tree species composition by differentially affecting seed germination under different environmental conditions.

Within-species leaf trait variation and ecological flexibility in resprouting tropical trees

2012 ◽  
Vol 28 (5) ◽  
pp. 527-530 ◽  
Author(s):  
Carl F. Salk
Keyword(s):  
Leaf Area ◽  
Tree Species ◽  
Environmental Changes ◽  
Functional Trait ◽  
Leaf Mass Per Area ◽  
Trait Variation ◽  
Leaf Functional Traits ◽  
Leaf Trait ◽  
Neotropical Tree ◽  
Ecological Flexibility

Plants have an inherent flexibility to respond to different environmental conditions. One axis of plant ecophysiological strategy is seen in the spectrum of leaf functional traits. Flexibility in these traits would be suggestive of plants’ phenotypic plasticity in response to environmental changes. This research seeks to identify differences between leaves of sprout and non-sprout shoots of a broad ecological range of neotropical tree species. Using a functional-trait approach, this study assesses a large pool of species for within-species physiological flexibility. Leaf mass per area (LMA) and leaf area were measured for plants of sprout and non-sprout origin for 26 tree species grown in a reforestation plantation in Panama. Sprouts had a consistently lower LMA than non-sprouts, but there was no consistent pattern for leaf area. These trends show that sprouts are more like pioneer species than conspecific saplings, a finding in general agreement with fast sprout growth seen in previous studies. Further, later-successional (high LMA) species showed a greater reduction of LMA in sprouts. These results show that tropical tree species adjust physiologically to changing ecological roles and suggest that certain species may be more resilient than realized to changing climate and disturbance patterns.

scholarly journals Association of “Candidatus Phytoplasma australiense” with Sudden Decline of Cabbage Tree in New Zealand

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 462-469 ◽  
Author(s):  
Mark T. Andersen ◽  
Ross E. Beever ◽  
Paul W. Sutherland ◽  
Richard L. S. Forster
Keyword(s):  
New Zealand ◽  
Rrna Gene ◽  
Mature Trees ◽  
Nested Polymerase Chain Reaction ◽  
Transmission Electron ◽  
Adult Trees ◽  
Leaf Yellowing ◽  
Pcr Products ◽  
One Step ◽  
Cabbage Tree

Sudden decline of the New Zealand cabbage tree (Cordyline australis) results in the rapid death of affected plants within months of first external symptoms becoming apparent. Symptoms, which have been observed in saplings and mature trees, include vascular discoloration and leaf yellowing followed by leaf desiccation and eventual plant collapse. Previous work failed to link the disease with any causal agent. A phytoplasma has now been detected in all symptomatic saplings and some symptomatic trees tested, using one-step and nested polymerase chain reaction (PCR) to amplify portions of the 16S rRNA gene. This phytoplasma was not detected in nonsymptomatic plants. Phytoplasma DNA was found in shoot and rhizome apices, leaves and wood tissue of saplings, and in the rhizome apex and trunk tissues of adult trees. Sequencing of the PCR products from selected samples indicated that the phytoplasma is “Candidatus Phytoplasma australiense.” Phytoplasma cells were detected by transmission electron microscopy in phloem sieve tubes of the rhizomes of affected saplings. One sapling with early symptoms recovered after injection with tetracycline antibiotic, but two saplings with advanced symptoms did not recover. It is concluded that “Candidatus Phytoplasma australiense” is present in symptomatic plants and is the cause of sudden decline.

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