Are Juglans neotropica Plantations Useful as a Refuge of Bryophytes Diversity in Tropical Areas?

Neotropical montane forests are considered biodiversity hotspots, where epiphytic bryophytes are an important component of the diversity, biomass and functioning of these ecosystems. We evaluated the richness and composition of bryophytes in secondary successional forests and mixed plantations of Juglans neotropica. In each forest type, the presence and cover of epiphytic bryophytes was registered in 400 quadrats of 20 cm × 30 cm. We analyzed the effects of canopy openness, diameter at breast height (DBH) and forest type on bryophyte richness, using a generalized linear model (GLM), as well as the changes in species composition using multivariate analysis. Fifty-five bryophyte species were recorded, of which 42 species were in secondary forests and 40 were in mixed plantations. Bryophyte richness did not change at forest level; however, at tree level, richness was higher in the mixed plantation of J. neotropica compared to the secondary forests, due to the presence of species adapted to high light conditions. On the other hand, bryophyte communities were negatively affected by the more open canopy in the mixed plantation of J. neotropica, species adapted to more humid conditions being less abundant. We conclude that species with narrow microclimatic niches are threatened by deforestation, and J. neotropica plantations do not act as refuge for drought-sensitive forest species present in secondary forests.

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Effect of distance from edge on exotic grass abundance in tropical dry forests bordering pastures in Ecuador

Journal of Tropical Ecology ◽

10.1017/s0266467417000062 ◽

2017 ◽

Vol 33 (2) ◽

pp. 170-173 ◽

Cited By ~ 1

Author(s):

Hannah Ruth Lyons-Galante ◽

Xavier Haro-Carrión

Keyword(s):

Forest Canopy ◽

Forest Type ◽

Canopy Openness ◽

Secondary Forests ◽

Grass Cover ◽

Pasture Grass ◽

Pasture Grasses ◽

The Pacific ◽

Explained Variation ◽

Exotic Grass

Abstract:We compared exotic pasture grass cover near the edges of 20–25-y-old secondary forests (N = 8) with those of mature forests (N = 8), bordering actively grazed pastures on the Pacific Coast of Ecuador. We estimated grass cover in 224 1 × 3-m plots along transects that ran from the pasture edge into forest interiors (11–44 m). Using a spline regression, we divided the transects into three segments: exterior (in the pasture), edge and interior (in the forest). With a stepwise regression, we tested the effect of transect section, forest type and distance from edge on grass cover. Forest type, distance from edge, interior transect section and the combined effect of distance from edge in both the interior and exterior sections explained variation in grass cover. Grass abundance was higher and penetrated further into secondary than mature forests. Edge proximity and differences in forest canopy openness likely favours recruitment and persistence of pasture grasses.

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Architectural strategies of Rhamnus cathartica (Rhamnaceae) in relation to canopy openness

Botany ◽

10.1139/b2012-069 ◽

2012 ◽

Vol 90 (10) ◽

pp. 976-989 ◽

Cited By ~ 17

Author(s):

Tristan Charles-Dominique ◽

Claude Edelin ◽

Jacques Brisson ◽

André Bouchard

Keyword(s):

Phenotypic Plasticity ◽

Full Description ◽

Canopy Openness ◽

Rhamnus Cathartica ◽

Light Conditions ◽

Key To Species ◽

Architectural Analysis ◽

Open Canopy ◽

Species Survival ◽

Whole Plant

While phenotypic plasticity is considered the major means that allows plant to cope with environmental heterogeneity, scant information is available on phenotypic plasticity of the whole-plant architecture in relation to ontogenic processes. We performed an architectural analysis to gain an understanding of the structural and ontogenic properties of common buckthorn ( Rhamnus cathartica L., Rhamnaceae) growing in the understory and under an open canopy. We found that ontogenic effects on growth need to be calibrated if a full description of phenotypic plasticity is to be obtained. Our analysis pointed to three levels of organization (or nested structural units) in R. cathartica. Their modulation in relation to light conditions leads to the expression of two architectural strategies that involve sets of traits known to confer competitive advantage in their respective environments. In the understory, the plant develops a tree-like form. Its strategy here is based on restricting investment in exploitation structures while promoting major vertical exploration and is probably key to species survival in the understory. Under an open canopy, the second strategy leads the plant to adopt a shrub-like shape. It develops densely branched exploitation structures and flowers abundantly and rapidly. This strategy perfectly matches its aggressive behaviour observed in full sunlight. We propose, as hypotheses, that these two light-related strategies are implicated in the ability of R. cathartica to outcompete the surrounding vegetation in a range of environmental conditions.

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Long-term Effects of Mixed Management on Arbuscular Mycorrhizal Fungal Community of Root and Soil in Juglans mandshurica Plantation

10.21203/rs.3.rs-36133/v1 ◽

2020 ◽

Author(s):

Li Ji ◽

Yan Zhang ◽

Yuchun Yang ◽

Lixue Yang ◽

Na Yang ◽

...

Keyword(s):

Relative Abundance ◽

Fungal Community ◽

Forest Type ◽

Mixed Forest ◽

Am Fungi ◽

Long Term Effects ◽

Juglans Mandshurica ◽

Mixed Plantations ◽

Mixed Plantation

Abstract Background: The establishment of mixed plantations is an effective way to improve soil fertility and increase forest productivity. Arbuscular mycorrhiza (AM) fungi are a kind of obligated symbiotic fungi, which can promote plants absorption of mineral nutrients and regulate intraspecific and interspecific competition. However, the effects of mixture on the community structure and abundance of AM fungi are still unclear. The Illumina MiSeq sequencing technique was used to determine the AM fungal community in the roots and soils of pure and mixed plantations (Juglans mandshurica × Larix gmelinii). The objective is to compare the response from root and rhizosphere soil AM fungal communities of Juglans mandshurica to long-term mixed plantation management. Results: Glomus and Paraglomus were the dominant genus in root samples, which accounted for more than 80% of the sequences. Compared with the pure plantation, the relative abundance of Glomus was higher in mixed plantation. Glomus, Diversispora and Paraglomus accounted for more than 85% of the sequences in soil samples. The relative abundance of Diversispora and Unclassified_c__Glomeromycetes were higher and lower in pure plantation, respectively. Samples of the Root_P (roots in pure plantation) had the highest number of unique OTUs (Operational Taxonomic Units), which were mainly composed of sequences belonging to unclassified_c__Glomeromycetes, Paraglomus, Glomus and Acaulospora. The amount of unique OTU detected in soil in pure and mixed plantation was relatively close. In the same types of sample (whether root or soil), the forest type did not have significant effect on AM fungal diversity, but the Sobs, Shannon, Chao1 and Ace indices of AM fungi in the roots were significantly higher than those in the soil. Conclusions: The mixed forest management had little effect on the AM fungal community in the root of Juglans mandshurica, but significantly changed the community composition of the soil AM fungi rather than diversity.

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Long-term Effects of Mixed Planting on Arbuscular Mycorrhizal Fungal Communities in the Roots and Soils of Juglans mandshurica Plantations

10.21203/rs.3.rs-36133/v2 ◽

2020 ◽

Author(s):

Li Ji ◽

Yan Zhang ◽

Yuchun Yang ◽

Lixue Yang ◽

Na Yang ◽

...

Keyword(s):

Fungal Community ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Soil Samples ◽

Fungal Communities ◽

Juglans Mandshurica ◽

Mixed Plantations ◽

Mixed Plantation ◽

Unique Otus

Abstract Background: Establishing mixed plantations is an effective way to improve soil fertility and increase forest productivity. Arbuscular mycorrhizal (AM) fungi are obligate symbiotic fungi that can promote mineral nutrient absorption and regulate intraspecific and interspecific competition in plants. However, the effects of mixed plantations on the community structure and abundance of AM fungi are still unclear. Illumina MiSeq sequencing was used to investigate the AM fungal community in the roots and soils of pure and mixed plantations (Juglans mandshurica × Larix gmelinii). The objective of this study is to compare the differential responses of the root and rhizosphere soil AM fungal communities of Juglans mandshurica to long-term mixed plantation management.Results: Glomus and Paraglomus were the dominant genera in the root samples, accounting for more than 80% of the sequences. Compared with that in the pure plantation, the relative abundance of Glomus was higher in the mixed plantation. Glomus, Diversispora and Paraglomus accounted for more than 85% of the sequences in the soil samples. The relative abundances of Diversispora and an unidentified genus of Glomeromycetes were higher and lower in the pure plantation, respectively. The Root_P samples (the roots in the pure plantation) had the highest number of unique OTUs (operational taxonomic units), which belonged mainly to an unidentified genus of Glomeromycetes, Paraglomus, Glomus and Acaulospora. The number of unique OTUs detected in the soil was lower than that in the roots. In both the root and soil samples, the forest type did not have a significant effect on AM fungal diversity, but the Sobs value and the Shannon, Chao1 and Ace indices of AM fungi in the roots were significantly higher than those in the soil.Conclusions: Mixed forest management had little effect on the AM fungal community of Juglans mandshurica roots and significantly changed the community composition of the soil AM fungi, but not the diversity.

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Characterizing Canopy Openness Across Large Forested Landscapes Using Spherical Densiometer and Smartphone Hemispherical Photography

Journal of Forestry ◽

10.1093/jofore/fvab046 ◽

2021 ◽

Author(s):

Katie L Beeles ◽

Jordon C Tourville ◽

Martin Dovciak

Keyword(s):

United States ◽

Large Range ◽

Forest Type ◽

High Elevation ◽

Canopy Openness ◽

Hemispherical Photography ◽

Forest Types ◽

Northeastern United States ◽

Closed Canopy ◽

The Right

Abstract Canopy openness is an important forest characteristic related to understory light environment and productivity. Although many methods exist to estimate canopy openness, comparisons of their performance tend to focus on relatively narrow ranges of canopy conditions and forest types. To address this gap, we compared two popular approaches for estimating canopy openness, traditional spherical densiometer and modern smartphone hemispherical photography, across a large range of canopy conditions (from closed canopy to large gaps) and forest types (from low-elevation broadleaf to high-elevation conifer forests) across four states in the northeastern United States. We took 988 field canopy openness measurements (494 per instrument) and compared them across canopy conditions using linear regression and t-tests. The extensive replication allowed us to quantify differences between the methods that may otherwise go unnoticed. Relative to the densiometer, smartphone photography overestimated low canopy openness (<10%) but it underestimated higher canopy openness (>10%), regardless of forest type. Study Implications We compared two popular ways of measuring canopy openness (smartphone hemispherical photography and spherical densiometer) across a large range of forest structures encountered in the northeastern United States. We found that, when carefully applied, the traditional spherical densiometer can characterize canopy openness across diverse canopy conditions (including closed canopies) as effectively as modern smartphone canopy photography. Although smartphone photography reduced field measurement time and complexity, it was more susceptible to weather than the densiometer. Although selection of the right method depends on study objectives, we provide a calibration for these two popular methods across diverse canopies.

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A Comparison of Forest Tree Crown Delineation from Unmanned Aerial Imagery Using Canopy Height Models vs. Spectral Lightness

Forests ◽

10.3390/f11060605 ◽

2020 ◽

Vol 11 (6) ◽

pp. 605 ◽

Cited By ~ 1

Author(s):

Jianyu Gu ◽

Heather Grybas ◽

Russell G. Congalton

Keyword(s):

Spectral Data ◽

Spatial Resolution ◽

Forest Type ◽

Canopy Height ◽

Aerial Imagery ◽

Tree Level ◽

Tree Crown ◽

Remotely Sensed Data ◽

Individual Tree ◽

Tree Crowns

Improvements in computer vision combined with current structure-from-motion photogrammetric methods (SfM) have provided users with the ability to generate very high resolution structural (3D) and spectral data of the forest from imagery collected by unmanned aerial systems (UAS). The products derived by this process are capable of assessing and measuring forest structure at the individual tree level for a significantly lower cost compared to traditional sources such as LiDAR, satellite, or aerial imagery. Locating and delineating individual tree crowns is a common use of remotely sensed data and can be accomplished using either UAS-based structural or spectral data. However, no study has extensively compared these products for this purpose, nor have they been compared under varying spatial resolution, tree crown sizes, or general forest stand type. This research compared the accuracy of individual tree crown segmentation using two UAS-based products, canopy height models (CHM) and spectral lightness information obtained from natural color orthomosaics, using maker-controlled watershed segmentation. The results show that single tree crowns segmented using the spectral lightness were more accurate compared to a CHM approach. The optimal spatial resolution for using lightness information and CHM were found to be 30 and 75 cm, respectively. In addition, the size of tree crowns being segmented also had an impact on the optimal resolution. The density of the forest type, whether predominately deciduous or coniferous, was not found to have an impact on the accuracy of the segmentation.

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Leaf physiological response to light environment of three tree fern species in a Mexican cloud forest

Journal of Tropical Ecology ◽

10.1017/s0266467413000230 ◽

2013 ◽

Vol 29 (3) ◽

pp. 217-228 ◽

Cited By ~ 8

Author(s):

K. Riaño ◽

O. Briones

Keyword(s):

Quantum Yield ◽

Cloud Forest ◽

Leaf Traits ◽

Light Sensitivity ◽

Canopy Openness ◽

Tree Fern ◽

Interspecific Differences ◽

Open Canopy ◽

Fern Species ◽

Light Saturation Point

Abstract:Abundance and physiology of three understorey tree fern species were compared in a Mexican cloud forest. We hypothesized that the distribution of species would be associated with canopy openness and leaf physiological characteristics. In gullies (1–2% full sun), Alsophila firma was abundant, Cyathea divergens was distributed in moderately open places (4–9%), and Lophosoria quadripinnata preferred more open canopy (9–30%). Although 11 leaf traits of five plants of each species growing under closed and open canopies over 1 y did not differ within species, there were significant interspecific differences. Alsophila firma had comparatively low maximum electron transport rate ETRmax (26.8 ± 1.81 μmol m−2 s−1) and ETR light saturation point (ETRLSP: 261 ± 36.1 μmol m−2 s−1), high specific leaf area (SLA), thin leaves and decreased quantum yield during a leaf desiccation experiment. Cyathea divergens had relatively high maximum quantum yield (0.84 ± 0.004), ETRmax (37.3 ± 1.8 μmol m−2 s−1) and ETRLSP (409 ± 40.0 μmol m−2 s−1). Lophosoria quadripinnata had comparatively thick leaves, low SLA, high predawn water potential, high density (606 ± 25.5 mm−2) and small length (0.026 ± 0.002 mm) stomata. The results support the hypothesis that light sensitivity shapes tree fern distribution in the cloud forest.

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Comparison of soil microfungal populations in disturbed and undisturbed forests in northern Wisconsin

Canadian Journal of Botany ◽

10.1139/b78-200 ◽

1978 ◽

Vol 56 (14) ◽

pp. 1702-1709 ◽

Cited By ~ 17

Author(s):

Donald T. Wicklow ◽

W. F. Whittingham

Keyword(s):

Species Composition ◽

Forest Type ◽

Loamy Sand ◽

Soil Horizons ◽

Clear Cutting ◽

Disturbed Areas ◽

Successional Forests ◽

Soil Dilution

Soil dilution plates were used to isolate populations of microfungi associated with the different soil horizons of five secondary successional forests, which arose after fire or clear-cutting, and three virginal (reference) stands. Ordinations of the populations within each horizon, based on similarities in the species composition of the microfungal communities, revealed the disturbed stands differed from their respective reference stands, although there was no consistent displacement of the stands in the ordinations. Most of the differences entailed alterations in frequency and (or) density, although a few species were predominant in one forest type but not in its counterpart. The most recently disturbed areas exhibited the greatest displacements from their reference stands. The ordinations suggested there is a sequential recovery of the mycoflora in the disturbed stands on loamy sand soils which would eventually result in a population similar to that in the reference stand.

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Effects of aspect and type of competition on the early performance of Nothofagus dombeyi and Nothofagus nervosa in a mixed plantation

Canadian Journal of Forest Research ◽

10.1139/x11-019 ◽

2011 ◽

Vol 41 (5) ◽

pp. 1075-1081 ◽

Cited By ~ 9

Author(s):

Pablo J. Donoso ◽

Ariel A. Muñoz ◽

Oscar Thiers ◽

Daniel P. Soto ◽

Claudio Donoso

Keyword(s):

The North ◽

The Andes ◽

Mixed Plantations ◽

Good Site ◽

Negative Effect ◽

Mixed Plantation ◽

Early Performance ◽

Nothofagus Dombeyi ◽

Nothofagus Nervosa ◽

Ecological Differences

In the Andes of Chile, two valuable Nothofagus tree species coexist (Nothofagus dombeyi (Mirb.) Oerst. and Nothofagus nervosa (Phil.) Krasser). They could provide an opportunity for mixed plantations because of their ecological differences. In a mixed plantation with a checkerboard design on a good site where the two species naturally coexist, we evaluated their performance according to aspect and type of competition. Nothofagus dombeyi had a greater survivorship (90% vs. 65%) and growth (twice in diameter and 20% greater in height). Forking was significantly lower in N. nervosa (23% vs. 70%). Aspect did not significantly affect the performance of N. dombeyi. The north aspect had a significant negative effect on survivorship of N. nervosa, but aspect did not significantly affect growth or forking of this species. The aspect – type of competition interaction was only significant for N. nervosa in diameter and marginally significant in height. The checkerboard design allowed for a clear separation of interspecific and intraspecific competition in this mixed plantation. Interspecific competition favored growth of N. nervosa on the north aspect (facilitation) and was detrimental to N. nervosa on the south aspect (competition). These results have a direct application when planting mixtures of species of complementary ecological characteristics that can increase the value of the plantation.

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Tecoma capensis (cape honeysuckle).

10.1079/isc.52954.20203483357 ◽

2020 ◽

Author(s):

Julissa Rojas-Sandoval

Keyword(s):

New Zealand ◽

Secondary Forests ◽

The World ◽

Tropical Areas ◽

Warm Temperate

Abstract T. capensis is an evergreen vine-like shrub that is widely cultivated in tropical areas and in warm temperate regions of the world as an ornamental and hedge plant (Orwa et al., 2009; USDA-ARS, 2016). T. capensis spreads by wind-dispersed seeds, but also by cuttings and rooted suckers which are traits that have helped it to escape from cultivation and become naturalized in secondary forests, forest margins and ruderal sites (Mutshinyalo and Notten, 2016; PIER, 2016; PROTA, 2016; Weeds of Australia, 2016). Currently, it is listed as invasive in Cuba, the Azores, Madeira, Australia and New Zealand, mainly due to its scrambling habit and the capability to form dense thickets that smother other plants (Oviedo Prieto et al., 2012; DAISIE, 2016; ISSG, 2016; Weeds of Australia, 2016).

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