Tree diversity in relation to maximum tree height: evidence for the harshness hypothesis of species diversity gradients

2017 ◽  
Vol 20 (3) ◽  
pp. 398-399 ◽  
Author(s):  
Christian O. Marks ◽  
Helene C. Muller-Landau ◽  
David Tilman
2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Wuming Zhang ◽  
Shangshu Cai ◽  
Xinlian Liang ◽  
Jie Shao ◽  
Ronghai Hu ◽  
...  

Abstract Background The universal occurrence of randomly distributed dark holes (i.e., data pits appearing within the tree crown) in LiDAR-derived canopy height models (CHMs) negatively affects the accuracy of extracted forest inventory parameters. Methods We develop an algorithm based on cloth simulation for constructing a pit-free CHM. Results The proposed algorithm effectively fills data pits of various sizes whilst preserving canopy details. Our pit-free CHMs derived from point clouds at different proportions of data pits are remarkably better than those constructed using other algorithms, as evidenced by the lowest average root mean square error (0.4981 m) between the reference CHMs and the constructed pit-free CHMs. Moreover, our pit-free CHMs show the best performance overall in terms of maximum tree height estimation (average bias = 0.9674 m). Conclusion The proposed algorithm can be adopted when working with different quality LiDAR data and shows high potential in forestry applications.


2020 ◽  
Vol 27 (1) ◽  
pp. 177-189
Author(s):  
Eric B. Gorgens ◽  
Matheus H. Nunes ◽  
Tobias Jackson ◽  
David Coomes ◽  
Michael Keller ◽  
...  

2020 ◽  
Vol 5 (2) ◽  
pp. 115-126 ◽  
Author(s):  
M Jannat ◽  
M Kamruzzaman ◽  
MA Hossain ◽  
MK Hossain

The study was conducted to explore tree species diversity of Renikhayong para Village Common Forest (VCF) of Bandarban hill district. Stratified random sampling was carried out to assess the tree species diversity of the VCF. Renikhayong Para VCF with an area of 40 acres of land has more than 85 tree species belonging to 31 families, where Euphorbiaceae family was dominant containing 11 species followed by Rubiaceae (7 species), Moraceae (7 species), Meliaceae (5 species), Mimosaceae (5 species), Combretaceae (4 species), Lauraceae (4 species) and Anacardiaceae (3 species). Dominant tree species was Grewia nervosa. Renikhayong para VCF has diverse floristic resources that are known from the Shannon-Wiener’s diversity index (4.007), Simpson’s diversity index (0.028), Margalef’s richness index (13.21) and Species evenness index (0.90). However, number of species and number of individuals both were highest in the height range of 5 - <10 m. Similar trend was observed in dbh classes. Number of individuals were highest in dbh range of 5 - <15 cm and the lowest in ≥ 55 cm. The results depict the presence of maximum small trees in the VCF and decreasing the number of trees with the increase of tree height (m) and dbh (cm). Presence of diverse tree species and diversity indices indicate the importance and potential of the VCF for conservation and sustainable use. J. Biodivers. Conserv. Bioresour. Manag. 2019, 5(2): 115-126


2015 ◽  
Vol 45 (9) ◽  
pp. 1172-1182 ◽  
Author(s):  
Dorota Dobrowolska

The aims of the investigation were to (i) quantify the changes in natural regeneration and stand structure, (ii) determine the role of deadwood in the process of regeneration following the disturbance, and (iii) determine the effect of disturbance severity on tree recruitment. The study was conducted in the Szast Protected Forest, which was established after a blowdown in 2002. The results showed that the trees were mainly wind-snapped. The basal area of the slightly disturbed stands increased over time. Herb cover increased, whereas moss cover decreased in 2011. The disturbance severity influenced the density of tree species regeneration, moss and herb ground cover, species diversity, average tree height, tree vitality, and damage caused by herbivores. The density of natural regeneration increased and new species became established after the disturbance. Scots pine (Pinus sylvestris L.) was the dominant tree species during the regeneration process except in the severely disturbed stand from which wood had been removed; in this case, birch was the dominant species. Wind disturbance increased species diversity and created a new forest with a particular species structure and trees that varied in age and height. The results of this study will be useful for foresters and policymakers to change the existing approaches to large-scale disturbances in the Polish forests.


2016 ◽  
Vol 19 (7) ◽  
pp. 743-751 ◽  
Author(s):  
Christian O. Marks ◽  
Helene C. Muller-Landau ◽  
David Tilman

1998 ◽  
Vol 55 (2) ◽  
pp. 295-316 ◽  
Author(s):  
J. Proctor ◽  
G. C. Argent ◽  
D. A. Madulid

Mount Giting-Giting is an ultramafic mountain on Sibuyan Island, Romblon Province, Republic of the Philippines. It was studied along the Mayo's Peak Ridge which had rainforest from about 200m up to c. 1550m. The grassland and scrub vegetation from 1550m to the summit (2050m) of Giting-Giting was not explored. The mean annual rainfall at the base of the mountain was c.2100mm which included a dry season around February and March. There was a notable increase in wind speed with altitude and there was about one hurricane (called a cyclone in the Philippines) per year. Analyses showed that the soils are acid ( 4.4–5.5), and have relatively low concentrations of Olsen extractable phosphorus (0.22–2.07μg g−1), low exchangeable potassium (0.04–0.41mEq 100g−1), and relatively low (for ultramafic soils) Mg/Ca quotients (0.31–2.87) and exchangeable nickel (1.0-23.8μg g−1). Coupled plots (of 0.25 or 0.04ha) were studied at altitudes from 325m to 1540m. All trees ≥ 10cm dbh were enumerated and structural features of the trees and smaller plants were quantified. The forests were all of fairly small stature (maximum tree height 24m) but dense (up to 2180 trees ha−1 in Lower Montane Forest (LMF) and up to 880 ha−1 in Upper Montane Forest (UMF)). While different taxa could be readily recognized, specific determinations were often impossible from the mainly sterile specimens. The LMF was species rich with up to at least 111 species of tree (≥ 10cm dbh) per 0.25-ha plot. There was no family clearly dominant in the two lower plots at 325m and 385m (where the Dipterocarpaceae were probably reduced by logging). At 770m and 860m the Dipterocarpaceae accounted for 12.9% and 14.7% of the basal area respectively. There was a surprisingly high representation of the Sapotaceae (25.9% of the basal area) at 1240m. At 1540m, the Araucariaceae (Agathis sp.) dominated one plot (37.1% of the basal area) and the Myrtaceae the other (72.4%).


2021 ◽  
Vol 26 (1) ◽  
pp. 71-81
Author(s):  
Inggita Utami ◽  
Radhitiya Anjar Pramana Putra ◽  
Muhammad Saputra Wibowo ◽  
Febriant Isabella Yusuf ◽  
Fahmiatul Husna ◽  
...  

Mount Merapi’s eruption has caused damage to the forests in the Mount Merapi National Park (MMNP). Nine years after the eruption, the vertical structure of vegetation can illustrate the progress of succession. This study aimed to analyze the tree composition and stratification in different forest damage levels after the 2010 Merapi eruption. The study was conducted in March 2019 at three stations, namely station A (heavy damage area), station B (moderate damage area), and station C (minor damage area). Vegetation parameters in each station were taken in a 10x100 plot and were processed using a tree profile diagram. Abiotic parameters were measured in each plot and analyzed using the correlation test. The results showed that the three stations were still dominated by the tree in Stratum C, but the tree density and tree height varied in proportion to the damage level. Station A in the heavy damage area has the lowest tree density (23 trees/0.1 ha) with a maximum tree height of 12 meters, in contrast to Station C in the minor damage area with tree density reaching 195 trees/0.1 ha and maximum tree height reaching 30 meters. Nine years after the Mount Merapi big eruption, the MMNP forests in Yogyakarta Province are still classified as young secondary forests.  Key words: diagram, profile, succession, structure, vertical


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