Natural regeneration of tree species in the Eastern Amazon: Short-term responses after reduced-impact logging

2017 ◽  
Vol 385 ◽  
pp. 97-103 ◽  
Author(s):  
Gustavo Schwartz ◽  
Vanessa Falkowski ◽  
Marielos Peña-Claros
2019 ◽  
Vol 48 (3) ◽  
pp. 417-425
Author(s):  
Md Khayrul Alam Bhuiyan ◽  
Md Akhter Hossain ◽  
Abdul Kadir Ibne Kamal ◽  
Mohammed Kamal Hossain ◽  
Mohammed Jashimuddin ◽  
...  

A study was conducted by using 5m × 5m sized 179 quadrates following multistage random sampling method for comparative regenerating tree species, quantitative structure, diversity, similarity and climate resilience in the degraded natural forests and plantations of Cox's Bazar North and South Forest Divisions. A total of 70 regenerating tree species were recorded representing maximum (47 species) from degraded natural forests followed by 43 species from 0.5 year 39 species from 1.5 year and 29 species from 2.5 year old plantations. Quantitative structure relating to ecological dominance indicated dominance of Acacia auriculiformis, Grewia nervosa and Lithocarpus elegans seedlings in the plantations whereas seedlings of Aporosa wallichii, Suregada multiflora and Grewia nervosa in degraded natural forests. The degraded natural forests possess higher natural regeneration potential as showed by different diversity indices. The dominance-based cluster analysis showed 2 major cluster of species under one of which multiple sub-clusters of species exists. Poor plant diversity and presence of regenerating exotic species in the plantations indicated poor climate resilience of forest ecosystem in terms of natural regeneration.


Author(s):  
Maame Esi Hammond ◽  
Radek Pokorný ◽  
Daniel Okae-Anti ◽  
Augustine Gyedu ◽  
Irene Otwuwa Obeng

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.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 528
Author(s):  
Jelena Kranjec Orlović ◽  
Damir Drvodelić ◽  
Marko Vukelić ◽  
Matea Rukavina ◽  
Danko Diminić ◽  
...  

When natural regeneration of Quercus robur stands is hampered by an insufficient acorn yield, human assisted sowing of acorns collected in non-affected stands and stored for some period of time is performed. To inhibit the development of fungi and acorn deterioration during storage, thermotherapy is usually applied by submerging acorns for 2.5 h in water heated to 41 °C. This research aimed to test the effect of four thermotherapy treatments of different durations and/or applied temperatures as well as short-term storage at −1 °C or 3 °C on acorn internal mycobiota and germination. Fungal presence in cotyledons was analyzed in 450 acorns by isolation of mycelia on artificial media, followed by a DNA-based identification. Germination of 2000 acorns was monitored in an open field trial. Thermotherapy significantly decreased fungal diversity, while storage at 3 °C increased the isolation frequency of several fungi, mainly Penicillium spp. The most frequently isolated fungi did not show a negative impact on acorn germination after short-term storage. The study confirmed the efficiency of thermotherapy in the eradication of a part of acorn internal mycobiota, but also its effect on the proliferation of fast-colonizing fungi during storage. However, the latter showed to be more stimulated by storage conditions, specifically by storage at 3 °C.


2018 ◽  
Vol 6 ◽  
pp. 324-331 ◽  
Author(s):  
Vera De Cauwer ◽  
Mubita Chaka ◽  
Percy Maruwa Chimwamurombe ◽  
Derick George ◽  
Hannel Ham ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
pp. 73-83
Author(s):  
MAHEDI HASAN LIMON ◽  
SAIDA HOSSAIN ARA ◽  
MOHAMMAD GOLAM KIBRIA

Natural regeneration is an indicator of a healthy forest, hence, understanding the influence of site factors on natural regeneration is a significant concern for ecologists. This work aimed to assess the impact of site factors on natural tree regeneration at Khadimnagar National Park (KNP). Biotic factors (tree density, tree species richness, and basal area), physical factors (elevation, canopy openness), and soil properties (bulk density, moisture content, soil pH, organic matter, sand, silt, and clay) data were investigated from 71 sample plots to examine their effects on natural regeneration density and richness in KNP. Stepwise multiple linear regression analysis was done to predict both regeneration density and regeneration richness. The results showed that soil pH (p<0.001), canopy openness (p<0.001), tree species richness (p<0.01), and bulk density (p<0.01) had a significant effect on regeneration density, explaining 42% of the total variation. Regeneration richness was driven by four factors: tree species richness (p<0.01), soil pH (p<0.001), elevation (p<0.01), and canopy openness (p<0.01) with a model that explained 60% of the total variation. This study observed that soil pH, tree species richness, and canopy openness are the main controlling factors that influenced both the density and richness of regenerating species in KNP. Therefore, these findings have implications for natural resource management, especially in selecting suitable silvicultural systems in a tropical forest under protected area management where enhanced tree cover and conservation of biodiversity are needed.


2006 ◽  
Vol 232 (1-3) ◽  
pp. 26-35 ◽  
Author(s):  
Claudia Azevedo-Ramos ◽  
Oswaldo de Carvalho ◽  
Benedito D. do Amaral

2017 ◽  
Vol 44 (11) ◽  
pp. 1075 ◽  
Author(s):  
Michael J. Aspinwall ◽  
Vinod K. Jacob ◽  
Chris J. Blackman ◽  
Renee A. Smith ◽  
Mark G. Tjoelker ◽  
...  

The effects of elevated CO2 on the short-term temperature response of leaf dark respiration (R) remain uncertain for many forest tree species. Likewise, variation in leaf R among populations within tree species and potential interactive effects of elevated CO2 are poorly understood. We addressed these uncertainties by measuring the short-term temperature response of leaf R in 15 provenances of Eucalyptus grandis W. Hill ex Maiden from contrasting thermal environments grown under ambient [CO2] (aCO2; 400 µmol mol–1) and elevated [CO2] (640 µmol mol–1; eCO2). Leaf R per unit area (Rarea) measured across a range of temperatures was higher in trees grown in eCO2 and varied up to 104% among provenances. However, eCO2 increased leaf dry mass per unit area (LMA) by 21%, and when R was expressed on a mass basis (i.e. Rmass), it did not differ between CO2 treatments. Likewise, accounting for differences in LMA among provenances, Rmass did not differ among provenances. The temperature sensitivity of R (i.e. Q10) did not differ between CO2 treatments or among provenances. We conclude that eCO2 had no direct effect on the temperature response of R in E. grandis, and respiratory physiology was similar among provenances of E. grandis regardless of home-climate temperature conditions.


2004 ◽  
Vol 26 (2) ◽  
pp. 150 ◽  
Author(s):  
J. E. D. Fox ◽  
S. K. Florentine ◽  
M. E. Westbrooke ◽  
C. Hurst

Observations are presented on the natural regeneration of Eucalyptus victrix L. Johnson and K. Hill (coolibah), the dominant tree species of grassy woodlands on the floodplain of the Fortescue River, north of Newman in the Pilbara district of Western Australia. The main objectives of this study were to examine: (i) survival of newly recruited E. victrix seedlings on flooded and burnt sites, and (ii) growth and survival of established plants in a gilgaied landscape. Populations of newly-recruited seedlings following flooding or fire were monitored opportunistically at 'Marillana' and 'Ethel Creek' stations, for up to two years from tagging. A population of saplings at 'Roy Hill' station was observed over eight years. Seedling densities of E. victrix in flooded sites were 0.32 and 1.03 plants/m2 in 1995 and 1997 respectively. Locally high densities reached from 1.2 to 17.7 plants/m2 on areas of 28 and 6 m2 respectively. At the burnt site at 'Ethel Creek', 1.30 plants/m2 were observed where 58 seedlings were recorded on an area of 445 m2 a year after a natural fire. Many of these persisted well into their second year, whereas seedlings recruited in the flooded sites generally lasted less than a year (250-376 days). In contrast, persistence of a cohort of 100 established saplings < 2 m tall in a gilgaied landscape at 'Roy Hill' was high. During 8 years of observations, only one sapling was lost. Those found at the edges of gilgais had attained greater heights (3.91 � 1.14 m) than saplings located inside (3.16 � 0.95 m) or on top (3.12 � 0.93 m) of the gilgais. This study demonstrates that the seedling stage in E. victrix is critical, in that once newly recruited individuals reach the sapling stage (0.611 m), mortality rates are much reduced. Unfortunately, it was not possible during the course of this study to locate a cohort of young seedlings that did survive and so any consideration of the conditions necessary for their survival is purely speculative.


Author(s):  
MA Hossain ◽  
MK Hossain ◽  
MS Alam ◽  
MM Abdullah Al Mamun

Structural composition based on diameter and height class distribution of the tree species of Dudhpukuria-Dhopachori Wildlife Sanctuary, Chittagong, Bangladesh was assessed. A total of 183 tree species having ≥ 10 DBH belonging to 125 genera and 48 families was recorded from the study area. Different species were found to dominate in different DBH classes, i.e. Aporosa wallichii (4.06%), Artocarpus chama (1.54%) and Dillenia pentagyna (0.38%) dominated 10 - < 25 cm, 25 - < 40 cm and 40 - < 55 cm DBH, respectively. Swintonia floribunda was found in maximum (7 out of 8) number of DBH classes. Both the percentage of tree individuals (73.18%) and number of species (169) were highest in 10-24.5cm DBH range. Similarly, Dipterocarpus turbinatus (14.5-24.4m and 24.5-34.4m) and Swintonia floribunda (34.5-44.4m and 44.5-54.4m) were dominant in two height ranges each. On the other hand, height range 4.5 - 14.4 m was dominated by Aporosa wallichii (4.36%). Dipterocarpus costatus, Artocarpus chama, Syzygium firmum and Bombax insigne were found in all the height classes. Both the number of tree species and number of individual stems (167 species; 1,684 individuals) were highest in the height range of 4.5-14.4m. The number of species and tree individuals decreased linearly with increasing height. All these indicate that, there was a sustainable natural regeneration and successful recruitment of Aporosa wallichii, Dipterocarpus turbinatus, Lithocarpus acuminata, Grewia nervosa and Artocarpus chama in Dudhpukuria-Dhopachori Wildlife Sanctuary. Dipterocarpus turbinatus was found as dominant species as it constitures maximum (5.56%) percentage of all tree individuals. The findings of the study may be useful for protection, conservation and sustainable management of Dudhpukuria-Dhopachori Wildlife Sanctuary.J. Biodivers. Conserv. Bioresour. Manag. 2017, 3(1): 17-30


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