scholarly journals Canopy Gap phase regeneration: A study in moist temperate forests of Central Himalayas, India

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Shalini Dhyani ◽  
R K Maikhuri ◽  
K S Rao
Keyword(s):  
Tree Species ◽  
Biological Diversity ◽  
Temperate Forests ◽  
Canopy Gap ◽  
Systematic Research ◽  
Gap Formation ◽  
Forest Patch ◽  
Dominant Form ◽  
Gap Phase ◽  
Edaphic Variables

Broad leaved forests continuously have some asynchronous and localized disturbance events.Tree fall gaps are the dominant form of such disturbances in these forests. Moist temperate forests dominated by Quercus leucotricophora in Garhwal were investigated for study. Ten random transect belts were established in a mixed broadleaved forest patch. The forest comprised of gaps, created by various natural processes. Gaps varied in size ranging from 48 to 589 m2. Microclimatic and edaphic variables of canopy gap and understorey areas were recorded to assess the parameters that influence gap phase regeneration. Forests of the studyarea comprised of gaps that varied in size and shape. Light intensity, soil moisture and soil temperature were prime micro-climatic variables influencing species recruitment in gaps.Species assemblage was recorded higher from gaps than forest understorey (20 and 17 tree species, respectively). Overall recruitment of tree species in understorey and canopy gaps was 3054 seedling ha-1 and 2277 saplings ha-1, respectively. The results obtained during our study show that gap formation process in moist temperate forests of Garhwal promotes a strong but temporary variations in microclimatic environment. This heterogeneity factor determines the biological diversity but needs more long term systematic research in Garhwal for better understanding.

Vegetation and gap dynamics of a tropical wet evergreen forest in the Western Ghats of Kerala, India

1994 ◽  
Vol 10 (3) ◽  
pp. 337-354 ◽  
Author(s):  
U. M. Chandrashekara ◽  
P. S. Ramakrishnan
Keyword(s):  
Tree Species ◽  
Western Ghats ◽  
Monsoon Season ◽  
Mixed Forest ◽  
Canopy Gap ◽  
Evergreen Forest ◽  
Gap Formation ◽  
Canopy Tree ◽  
Canopy Tree Species ◽  
The Western Ghats

ABSTRACTThe wet evergreen forest of Nelliampathy in the Western Ghats of Kerala in India is a mixed forest with a high species diversity and basal cover. In this relatively undisturbed ecosystem, canopy gaps are largely formed through single tree fall, but gaps through branch fall, crown fall, standing dead trees or multiple tree fall also occur. Canopy gap formation is more (over 82% of the total gaps created) during the monsoon season. The mean number of gaps formed in this forest is 1.13 ha−1 y−1 and the turnover rate is 83 years. The majority of the gaps created (over 70%) are of smaller size (≥ 100 m2). In this forest, while some top canopy tree species (those capable of exceeding 25 m in height at maturity) such as Palaquium ellipticum and Mesua nagassarium are well represented in seedling, sapling and mature tree stages, others like Aglaia exstipulata and Mastixia arborea are observed only as saplings and/or mature trees with no seedling populations. The possible reasons for these two types of regeneration behaviour by top canopy tree species in the context of canopy gap size and seasonality in gap formation are discussed.

scholarly journals The composition and diversity of natural regeneration of tree species in gaps under different intensities of forest disturbance

2021 ◽  
Author(s):  
Maame Esi Hammond ◽  
Radek Pokorný ◽  
Daniel Okae-Anti ◽  
Augustine Gyedu ◽  
Irene Otwuwa Obeng
Keyword(s):  
Tree Species ◽  
Natural Regeneration ◽  
Forest Disturbance ◽  
Forest Site ◽  
Gap Formation ◽  
Tree Species Composition ◽  
Forest Sites ◽  
Significant Difference ◽  
Shade Tolerant Species ◽  
Disturbed Forest

AbstractThe positive ecological interaction between gap formation and natural regeneration has been examined but little research has been carried out on the effects of gaps on natural regeneration in forests under different intensities of disturbance. This study evaluates the composition, diversity, regeneration density and abundance of natural regeneration of tree species in gaps in undisturbed, intermittently disturbed, and disturbed forest sites. Bia Tano Forest Reserve in Ghana was the study area and three gaps each were selected in the three forest site categories. Ten circular subsampling areas of 1 m2 were delineated at 2 m spacing along north, south, east, and west transects within individual gaps. Data on natural regeneration < 350 cm height were gathered. The results show that the intensity of disturbance was disproportional to gap size. Species diversity differed significantly between undisturbed and disturbed sites and, also between intermittently disturbed and disturbed sites for Simpson’s (1-D), Equitability (J), and Berger–Parker (B–P) indices. However, there was no significant difference among forest sites for Shannon diversity (H) and Margalef richness (MI) indices. Tree species composition on the sites differed. Regeneration density on the disturbed site was significantly higher than on the two other sites. Greater abundance and density of shade-dependent species on all sites identified them as opportunistic replacements of gap-dependent pioneers. Pioneer species giving way to shade tolerant species is a natural process, thus make them worst variant in gap regeneration.

scholarly journals Over half of western United States' most abundant tree species in decline

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hunter Stanke ◽  
Andrew O. Finley ◽  
Grant M. Domke ◽  
Aaron S. Weed ◽  
David W. MacFarlane
Keyword(s):  
United States ◽  
Tree Species ◽  
Tree Mortality ◽  
Temperate Forests ◽  
Size Structure ◽  
Forest Disturbance ◽  
Population Decline ◽  
Western United States ◽  
Scale Transformation ◽  
Forest Composition

AbstractChanging forest disturbance regimes and climate are driving accelerated tree mortality across temperate forests. However, it remains unknown if elevated mortality has induced decline of tree populations and the ecological, economic, and social benefits they provide. Here, we develop a standardized forest demographic index and use it to quantify trends in tree population dynamics over the last two decades in the western United States. The rate and pattern of change we observe across species and tree size-distributions is alarming and often undesirable. We observe significant population decline in a majority of species examined, show decline was particularly severe, albeit size-dependent, among subalpine tree species, and provide evidence of widespread shifts in the size-structure of montane forests. Our findings offer a stark warning of changing forest composition and structure across the western US, and suggest that sustained anthropogenic and natural stress will likely result in broad-scale transformation of temperate forests globally.

scholarly journals PRESERVATION OF PRIMARY FOREST CHARACTERISTICS DESPITE FRAGMENTATION AND ISOLATION IN A FOREST REMNANT FROM VIÇOSA, MG, BRAZIL1

2015 ◽  
Vol 39 (6) ◽  
pp. 985-994 ◽  
Author(s):  
Markus Gastauer ◽  
Marcos Eduardo Guerra Sobral ◽  
João Augusto Alves Meira-Neto
Keyword(s):  
Species Richness ◽  
Endemic Species ◽  
Tree Species ◽  
Primary Forest ◽  
Forest Patch ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Forest Remnant ◽  
Primary Forests ◽  
Biotic Resources

According to its owners, the Forest of Seu Nico (FSN) from the Viçosa municipality, Minas Gerais, Brazil, never has been logged and is therefore considered a primary forest. Nevertheless, the forest patch suffered impacts due to selective wood and non-timber extraction, fragmentation and isolation. Aim of this study was to test if the FSN, despite impacts, preserved characteristics of primary forests, which are elevated percentages of non-pioneer (>90%), animal-dispersed (>80 %), understory (>50%) and endemic species (~40%). For that, all trees with diameter at breast height equal or major than 3.2 cm within a plot of 100 x 100 m were identified. With 218 tree species found within this hectare, the FSN's species richness is outstanding for the region. The percentages of non-pioneer (92 %), animal-dispersed (85 %), understory (55 %) and endemic species (39.2 %) from the FSN fulfill the criteria proposed for primary forest. Therefore, we conclude that the FSN maintained its characteristics as a primary forest which highlights its importance for the conservation of biotic resources in the region, where similar fragments are lacking or not described yet.

scholarly journals Canopy gap edge determination and the importance of gap edges for plant diversity

Web Ecology ◽  
2002 ◽  
Vol 3 (1) ◽  
pp. 1-5 ◽  
Author(s):  
D. Salvador-Van Eysenrode ◽  
F. Kockelbergh ◽  
J. Bogaert ◽  
I. Impens ◽  
P. Van Hecke
Keyword(s):  
Fagus Sylvatica ◽  
Plant Diversity ◽  
Forest Cover ◽  
Beech Forest ◽  
Canopy Gaps ◽  
Canopy Gap ◽  
Structural Elements ◽  
Forest Patch ◽  
Young Forest ◽  
Maintenance Of Diversity

Abstract. Canopy gaps, i.e. openings in the forest cover caused by the fall of structural elements, are considered to be important for the maintenance of diversity and for the forest cycle. A gap can be considered as a young forest patch in the forest matrix, composed of interior surrounded by an edge, both enclosed by a perimeter. Much of the attention has been focused on the gap interior. However, at gap edges the spectrum of regeneration opportunities for plants may be larger than in the interior. Although definitions of gap are still discussed, any definition can describe it in an acceptable way, if justified, but defining edges is complicated and appropriate descriptors should be used. A method to determine gap interior and edge, using light as a descriptor, is presented with an example of gaps from a beech forest (Fagus sylvatica) in Belgium. Also, the relevance and implications of gap edges for plant diversity and calculation of forest turnover is discussed.

scholarly journals Towards Conservation of Genetic Variation of Tropical Tree Species With Differing Successional Status: The Case of Mansonia altissima A. Chev and Triplochiton scleroxylon K. Schum

2019 ◽  
Vol 12 ◽  
pp. 194008291986426
Author(s):  
Akin Akinnagbe ◽  
Oliver Gailing ◽  
Reiner Finkeldey ◽  
Amadu Lawal
Keyword(s):  
Genetic Diversity ◽  
Human Impact ◽  
Tree Species ◽  
Human Impacts ◽  
Genetic Erosion ◽  
Primary Forest ◽  
Timber Species ◽  
Pioneer Species ◽  
Forest Patch ◽  
Successional Status

Two important West African timber tree species with differing successional status, Mansonia altissima A. Chev and Triplochiton scleroxylon K. Schum were investigated in this study. Triplochiton scleroxylon is a pioneer species found in open forests, whereas Mansonia altissima is a nonpioneer light-demanding tree species occurring in closed forests. Amplified fragment length polymorphism markers were used to compare the genetic diversities of these two timber species in stands with different degrees of human impact (isolated forest patch, logged forest, farmland, plantation, and primary forest). Contrasting effects of human impact on genetic diversity were detected for these two timber species. The results suggested severe effects of human impact on the genetic diversity of Mansonia altissima, a nonpioneer species. However, no adverse effect was recorded in Triplochiton scleroxylon, a pioneer species. These findings indicate that nonpioneer tree species could be more prone to genetic erosion than pioneer tree species as a result of adverse human impacts. Therefore, conservation of genetic diversity in both pioneer and nonpioneer tree species populations would likely necessitate different measures.

Ascomycetes (Fungi) from the relic forest of Fagus grandifolia subsp. mexicana in eastern Mexico

Phytotaxa ◽  
2019 ◽  
Vol 418 (1) ◽  
pp. 1-41
Author(s):  
TANIA RAYMUNDO ◽  
RICARDO VALENZUELA ◽  
YENITZE GARCÍA-MARTÍNEZ ◽  
MARCO ANTONIO BRAVO-ÁLVAREZ ◽  
JULIO CÉSAR RAMÍREZ-MARTÍNEZ ◽  
...  
Keyword(s):  
Tree Species ◽  
New Records ◽  
Cloud Forest ◽  
Fagus Grandifolia ◽  
Tropical Montane Cloud Forest ◽  
Forest Patch ◽  
Montane Cloud Forest ◽  
Close Relationship ◽  
Decaying Wood ◽  
First Time

An intensive recollection of Ascomycetes was carried out within the best-known preserved Mexican tropical montane cloud forest patch dominated by Fagus grandifolia subsp. mexicana. This relict tree species has a fragmented and restricted distribution in the mountains of eastern Mexico. Other Mexican endemic Fagaceae species show dominance in this forest patch. Historically, records of Ascomycetes fungi in this type of forest are scarce. The present study found 170 specimens belonging to 61 species, of which 30 are new records for the state, while 10 species are cited for the first time in the country. Most of the recorded Ascomycetes species are intimately associated to Fagaceae tree species (Fagus and Quercus). From these, many are endophytes belonging to the Order Xylariales, while others grow on decaying wood, fallen branches, leaves and/or litter (possibly mycorrhizal). This interesting close relationship between fungi and Fagaceae trees must be studied and analyzed.

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