scholarly journals Species diversity in restoration plantings: Important factors for increasing the diversity of threatened tree species in the restoration of the Araucaria forest ecosystem

2019 ◽  
Vol 41 (2) ◽  
pp. 84-93 ◽  
Author(s):  
Taylor E. Shaw
2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Van Vien Pham ◽  
Christian Ammer ◽  
Peter Annighöfer ◽  
Steffi Heinrichs

Abstract Background The ability of overstory tree species to regenerate successfully is important for the preservation of tree species diversity and its associated flora and fauna. This study investigated forest regeneration dynamics in the Cat Ba National Park, a biodiversity hotspot in Vietnam. Data was collected from 90 sample plots (500 m2) and 450 sub-sample plots (25 m2) in regional limestone forests. We evaluated the regeneration status of tree species by developing five ratios relating overstory and regeneration richness and diversity. By examining the effect of environmental factors on these ratios, we aimed to identify the main drivers for maintaining tree species diversity or for potential diversity gaps between the regeneration and the overstory layer. Our results can help to increase the understanding of regeneration patterns in tropical forests of Southeast Asia and to develop successful conservation strategies. Results We found 97 tree species in the regeneration layer compared to 136 species in the overstory layer. The average regeneration density was 3764 ± 1601 per ha. Around 70% of the overstory tree species generated offspring. According to the International Union for Conservation of Nature’s Red List, only 36% of threatened tree species were found in the regeneration layer. A principal component analysis provided evidence that the regeneration of tree species was slightly negatively correlated to terrain factors (percentage of rock surface, slope) and soil properties (cation exchange capacity, pH, humus content, soil moisture, soil depth). Contrary to our expectations, traces of human impact and the prevailing light conditions (total site factor, gap fraction, openness, indirect site factor, direct site factor) had no influence on regeneration density and composition, probably due to the small gradient in light availability. Conclusion We conclude that the tree species richness in Cat Ba National Park appears to be declining at present. We suggest similar investigations in other biodiversity hotspots to learn whether the observed trend is a global phenomenon. In any case, a conservation strategy for the threatened tree species in the Cat Ba National Park needs to be developed if tree species diversity is to be maintained.


2018 ◽  
Vol 19 (6) ◽  
pp. 2213-2218
Author(s):  
SUTOMO SUTOMO ◽  
I DEWA PUTU DARMA ◽  
ARIEF PRIYADI ◽  
RAJIF IRYADI

Sutomo, Darma IDP, Priyadi A, Iryadi R. 2018. Trees species diversity and indicator species in Bedugul forest ecosystem, Bali, Indonesia. Biodiversitas 19: 2213-2218. Bedugul area is an endorheic basin landscape with 3 lakes namely, Beratan, Buyan, Tamblingan, which is surrounded by Bukit Mangu, Tapak and Lesung. Topography of the area shows sloping to steep slopes with altitude on the lake surface ± 1,100 m asl and the highest peak of Bukit Mangu 2002 m asl. Ecological studies have not been optimal so identification of comprehensive ecological potential is carried out. Measurement of tree vegetation diversity was carried out by Centered Quarter Method and important value ratio analysis and location elevation class. The results of the inventory of tree species diversity in the Bedugul Bali forest area recorded 35 species and 13 indicator tree species. From the number of indicator tree species in the Mangu hill forest area there are 5 types of Ficus sp, Platea latifolia, Polyosma integrifolia, Lindera sp. and Syzygium sp., Bukit Tapak forest area consists of 4 species, Casuarina junghuhniana,  Acronychia trifoliate,  Astronia spectabilis and Homalanthus giganteus, the forest area of ​​Bukit Lesung consists of 4 types of Lophopetalum javanicum, Syzygium racemosum, Dysoxylum nutans and Dendrocnide peltata.


Author(s):  
Betina Kellermann ◽  
André Eduardo Biscaia Lacerda

Abstract Aims Assessing the role of a dominant native bamboo species on tree species diversity and structure in the medium term. Methods Over a 7-year period, we studied the natural regeneration of two dominant forest types in Southern Brazil (Araucaria Forest or AF; Bamboo Forest or BF) after a bamboo (Merostachys skvortzovii Send.) die-off between 2004 and 2006. The study was carried out in the Embrapa Research Station in Caçador, Santa Catarina State, Brazil. Important Findings The die-off provided ideal conditions for the establishment of several species and it kickstarted forest succession dynamics, which in turn affected regeneration diversity. Tree species richness was relatively stable with a transitory increase between 2007 and 2014 in both AF and BF. However, species richness rose in BF because of a relative increase in abundance of some species (especially late and secondary species) while a plunge in some pioneer species drove an increase in diversity. Overall, we found that BF has a lower diversity of recruits and that density declined over time, while AF is more diverse, with a more stable density. In BF, the bamboo die-off created optimal conditions for initial regeneration development (mainly fast-growing pioneer trees), which quickly transited to higher size classes. Yet, after this initial stage of pioneer recruitment, the number of recruits dropped followed by a virtual absence of growth regardless of the species group as a result of a quick bamboo reestablishment. As bamboo recreated a dense understory it reduced species diversity to original levels, suggesting a self-maintaining cycle that halts forest succession. On the other hand, the bamboo die-off had little impact on AF where a slow recruitment process typical of old-growth forests was observed. The results indicate that the die-off event had a temporary effect on species diversity i.e. restricted to forests where bamboos are dominant in a similar process described in other southern South American forests. As the first study to observe the medium-term forest dynamics related to bamboo die-off, we can conclude that when being dominant, native bamboos can hinder forest regeneration, maintaining lower levels of diversity and arresting forest succession that lasts well beyond the short-term, post-die-off effects. Many forest fragments in the region are dominated by bamboos, thus their potential for conservation is at risk and requires appropriate management.


2021 ◽  
Vol 14 ◽  
pp. 194008292199541
Author(s):  
Xavier Haro-Carrión ◽  
Bette Loiselle ◽  
Francis E. Putz

Tropical dry forests (TDF) are highly threatened ecosystems that are often fragmented due to land-cover change. Using plot inventories, we analyzed tree species diversity, community composition and aboveground biomass patterns across mature (MF) and secondary forests of about 25 years since cattle ranching ceased (SF), 10–20-year-old plantations (PL), and pastures in a TDF landscape in Ecuador. Tree diversity was highest in MF followed by SF, pastures and PL, but many endemic and endangered species occurred in both MF and SF, which demonstrates the importance of SF for species conservation. Stem density was higher in PL, followed by SF, MF and pastures. Community composition differed between MF and SF due to the presence of different specialist species. Some SF specialists also occurred in pastures, and all species found in pastures were also recorded in SF indicating a resemblance between these two land-cover types even after 25 years of succession. Aboveground biomass was highest in MF, but SF and Tectona grandis PL exhibited similar numbers followed by Schizolobium parahyba PL, Ochroma pyramidale PL and pastures. These findings indicate that although species-poor, some PL equal or surpass SF in aboveground biomass, which highlights the critical importance of incorporating biodiversity, among other ecosystem services, to carbon sequestration initiatives. This research contributes to understanding biodiversity conservation across a mosaic of land-cover types in a TDF landscape.


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