scholarly journals Patterns of Tree Mortality in a Monodominant Tropical Forest

10.5772/29762 ◽  
2012 ◽  
Author(s):  
Patrick J.
2018 ◽  
Vol 34 (3) ◽  
pp. 157-175 ◽  
Author(s):  
John B. Vincent ◽  
Benjamin L. Turner ◽  
Clant Alok ◽  
Vojtech Novotny ◽  
George D. Weiblen ◽  
...  

Abstract:Long-term forest dynamics plots in the tropics tend to be situated on stable terrain. This study investigated forest dynamics on the north coast of New Guinea where active subduction zones are uplifting lowland basins and exposing relatively young sediments to rapid weathering. We examined forest dynamics in relation to disturbance history, topography and soil nutrients based on partial re-census of the 50-ha Wanang Forest Dynamics Plot in Papua New Guinea. The plot is relatively high in cations and phosphorus but low in nitrogen. Soil nutrients and topography accounted for 29% of variation in species composition but only 4% of variation in basal area. There were few areas of high biomass and most of the forest was comprised of small-diameter stems. Approximately 18% of the forest was less than 30 y old and the annual tree mortality rate of nearly 4% was higher than in other tropical forests in South-East Asia and the neotropics. These results support the reputation of New Guinea's forests as highly dynamic, with frequent natural disturbance. Empirical documentation of this hypothesis expands our understanding of tropical forest dynamics and suggests that geomorphology might be incorporated in models of global carbon storage especially in regions of unstable terrain.


2004 ◽  
Vol 359 (1443) ◽  
pp. 367-380 ◽  
Author(s):  
Jos Barlow ◽  
Carlos A. Peres

Over the past 20 years the combined effects of El Niño–induced droughts and land–use change have dramatically increased the frequency of fire in humid tropical forests. Despite the potential for rapid ecosystem alteration and the current prevalence of wildfire disturbance, the consequences of such fires for tropical forest biodiversity remain poorly understood. We provide a pan–tropical review of the current state of knowledge of these fires, and include data from a study in a seasonally dry terra firme forest of central Brazilian Amazonia. Overall, this study supports predictions that rates of tree mortality and changes in forest structure are strongly linked to burn severity. The potential consequences for biomass loss and carbon emissions are explored. Despite the paucity of data on faunal responses to tropical forest fires, some trends are becoming apparent; for example, large canopy frugivores and understorey insectivorous birds appear to be highly sensitive to changes in forest structure and composition during the first 3 years after fires. Finally, we appraise the management implications of fires and evaluate the viability of techniques and legislation that can be used to reduce forest flammability, prevent anthropogenic ignition sources from coming into contact with flammable forests and aid the post–fire recovery process.


1996 ◽  
Vol 23 (3) ◽  
pp. 235-248 ◽  
Author(s):  
Oliver L. Phillips

SummaryAnalyzing permanent plot data from 40 tropical forest sites, Phillips and Gentry (1994) found that there has been a significant tendency for tree turnover – as measured by tree mortality and recruitment – to increase since the 1950s. The dataset is now substantially improved, and includes 67 mature forest sites with turnover data representing most of the major tropical forest regions of the world. This paper presents an updated and expanded analysis of the latest data, and confirms that tree turnover has increased in mature tropical forest plots. Several artifactual explanations have been suggested but none are supported by the available data, suggesting that surviving mature tropical forests have been recently affected by large-scale anthropogenic or natural change. The effects of increased turnover may include impacts on future global atmosphere, climate, and biodiversity. Better understanding of the ecological changes in mature tropical forests depends on progress in two critical research areas – a ground-based monitoring network of long-term, fully identified tropical forest plots, and controlled manipulation of atmospheric conditions in forest experiments. Research activity in both areas needs to be substantially increased if we are to understand and predict the complex interactions between tropical forest ecology and global environmental change.


2021 ◽  
Vol 18 (24) ◽  
pp. 6517-6531
Author(s):  
Raquel Fernandes Araujo ◽  
Samuel Grubinger ◽  
Carlos Henrique Souza Celes ◽  
Robinson I. Negrón-Juárez ◽  
Milton Garcia ◽  
...  

Abstract. A mechanistic understanding of how tropical-tree mortality responds to climate variation is urgently needed to predict how tropical-forest carbon pools will respond to anthropogenic global change, which is altering the frequency and intensity of storms, droughts, and other climate extremes in tropical forests. We used 5 years of approximately monthly drone-acquired RGB (red–green–blue) imagery for 50 ha of mature tropical forest on Barro Colorado Island, Panama, to quantify spatial structure; temporal variation; and climate correlates of canopy disturbances, i.e., sudden and major drops in canopy height due to treefalls, branchfalls, or the collapse of standing dead trees. Canopy disturbance rates varied strongly over time and were higher in the wet season, even though wind speeds were lower in the wet season. The strongest correlate of monthly variation in canopy disturbance rates was the frequency of extreme rainfall events. The size distribution of canopy disturbances was best fit by a Weibull function and was close to a power function for sizes above 25 m2. Treefalls accounted for 74 % of the total area and 52 % of the total number of canopy disturbances in treefalls and branchfalls combined. We hypothesize that extremely high rainfall is a good predictor because it is an indicator of storms having high wind speeds, as well as saturated soils that increase uprooting risk. These results demonstrate the utility of repeat drone-acquired data for quantifying forest canopy disturbance rates at fine temporal and spatial resolutions over large areas, thereby enabling robust tests of how temporal variation in disturbance relates to climate drivers. Further insights could be gained by integrating these canopy observations with high-frequency measurements of wind speed and soil moisture in mechanistic models to better evaluate proximate drivers and with focal tree observations to quantify the links to tree mortality and woody turnover.


2019 ◽  
Vol 32 (4) ◽  
Author(s):  
Edwin Werf ◽  
Yonky Indrajaya ◽  
Frits Mohren ◽  
Ekko C. Ierland

2018 ◽  
Vol 373 (1760) ◽  
pp. 20170311 ◽  
Author(s):  
Patrick Meir ◽  
Maurizio Mencuccini ◽  
Oliver Binks ◽  
Antonio Lola da Costa ◽  
Leandro Ferreira ◽  
...  

Are short-term responses by tropical rainforest to drought (e.g. during El Niño) sufficient to predict changes over the long-term, or from repeated drought? Using the world's only long-term (16-year) drought experiment in tropical forest we examine predictability from short-term measurements (1–2 years). Transpiration was maximized in droughted forest: it consumed all available throughfall throughout the 16 years of study. Leaf photosynthetic capacity was maintained, but only when averaged across tree size groups. Annual transpiration in droughted forest was less than in control, with initial reductions (at high biomass) imposed by foliar stomatal control. Tree mortality increased after year three, leading to an overall biomass loss of 40%; over the long-term, the main constraint on transpiration was thus imposed by the associated reduction in sapwood area. Altered tree mortality risk may prove predictable from soil and plant hydraulics, but additional monitoring is needed to test whether future biomass will stabilize or collapse. Allocation of assimilate differed over time: stem growth and reproductive output declined in the short-term, but following mortality-related changes in resource availability, both showed long-term resilience, with partial or full recovery. Understanding and simulation of these phenomena and related trade-offs in allocation will advance more effectively through greater use of optimization and probabilistic modelling approaches. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications’.


1999 ◽  
Vol 116 (1-3) ◽  
pp. 247-252 ◽  
Author(s):  
Michelle A Pinard ◽  
Francis E Putz ◽  
Juan Carlos Licona

2004 ◽  
Vol 92 (6) ◽  
pp. 929-944 ◽  
Author(s):  
SIMON L. LEWIS ◽  
OLIVER L. PHILLIPS ◽  
DOUGLAS SHEIL ◽  
BARBARA VINCETI ◽  
TIMOTHY R. BAKER ◽  
...  

Oecologia ◽  
2021 ◽  
Author(s):  
Miriam San-José ◽  
Leland Werden ◽  
Chris J. Peterson ◽  
Federico Oviedo-Brenes ◽  
Rakan A. Zahawi

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