scholarly journals Variability in solar radiation and temperature explains observed patterns and trends in tree growth rates across four tropical forests

2012 ◽  
Vol 279 (1744) ◽  
pp. 3923-3931 ◽  
Author(s):  
Shirley Xiaobi Dong ◽  
Stuart J. Davies ◽  
Peter S. Ashton ◽  
Sarayudh Bunyavejchewin ◽  
M. N. Nur Supardi ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Tropical Forest ◽  
Temporal Variation ◽  
Tropical Forests ◽  
Tree Growth ◽  
Growth Rates ◽  
Global Climate ◽  
Night Time ◽  
Temperature And Precipitation

The response of tropical forests to global climate variability and change remains poorly understood. Results from long-term studies of permanent forest plots have reported different, and in some cases opposing trends in tropical forest dynamics. In this study, we examined changes in tree growth rates at four long-term permanent tropical forest research plots in relation to variation in solar radiation, temperature and precipitation. Temporal variation in the stand-level growth rates measured at five-year intervals was found to be positively correlated with variation in incoming solar radiation and negatively related to temporal variation in night-time temperatures. Taken alone, neither solar radiation variability nor the effects of night-time temperatures can account for the observed temporal variation in tree growth rates across sites, but when considered together, these two climate variables account for most of the observed temporal variability in tree growth rates. Further analysis indicates that the stand-level response is primarily driven by the responses of smaller-sized trees (less than 20 cm in diameter). The combined temperature and radiation responses identified in this study provide a potential explanation for the conflicting patterns in tree growth rates found in previous studies.

Long-term potential for tropical-forest degradation due to deforestation and fires in the Brazilian Amazon

Biologia ◽  
2009 ◽  
Vol 64 (3) ◽  
Author(s):  
Manoel Cardoso ◽  
Carlos Nobre ◽  
Gilvan Sampaio ◽  
Marina Hirota ◽  
Dalton Valeriano ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Tropical Forests ◽  
Large Scale ◽  
Global Climate ◽  
Brazilian Amazon ◽  
Forest Degradation ◽  
Large Scale Data ◽  
Fire Activity ◽  
Arc Of Deforestation

AbstractBiome models of the global climate-vegetation relationships indicate that most of the Brazilian Amazon has potential for being covered by tropical forests. From current land-use processes observed in the region, however, substantial deforestation and fire activity have been verified in large portions of the region, particularly along the Arc of Deforestation. In a first attempt to evaluate the long-term potential for tropical-forest degradation due to deforestation and fires in the Brazilian Amazon, we analysed large-scale data on fire activity and climate factors that drive the distribution of tropical forests in the region. The initial analyses and results from this study lead to important details on the relations between these quantities and have important implications for building future parameterizations of the vulnerability of tropical forests in the region.

scholarly journals Long-Term Nitrogen Addition Decreases Soil Carbon Mineralization in an N-Rich Primary Tropical Forest

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 734
Author(s):  
Xiankai Lu ◽  
Qinggong Mao ◽  
Zhuohang Wang ◽  
Taiki Mori ◽  
Jiangming Mo ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Tropical Forest ◽  
Soil Carbon ◽  
Tropical Forests ◽  
Carbon Mineralization ◽  
N Deposition ◽  
Soil Carbon Mineralization ◽  
N Additions

Anthropogenic elevated nitrogen (N) deposition has an accelerated terrestrial N cycle, shaping soil carbon dynamics and storage through altering soil organic carbon mineralization processes. However, it remains unclear how long-term high N deposition affects soil carbon mineralization in tropical forests. To address this question, we established a long-term N deposition experiment in an N-rich lowland tropical forest of Southern China with N additions such as NH4NO3 of 0 (Control), 50 (Low-N), 100 (Medium-N) and 150 (High-N) kg N ha−1 yr−1, and laboratory incubation experiment, used to explore the response of soil carbon mineralization to the N additions therein. The results showed that 15 years of N additions significantly decreased soil carbon mineralization rates. During the incubation period from the 14th day to 56th day, the average decreases in soil CO2 emission rates were 18%, 33% and 47% in the low-N, medium-N and high-N treatments, respectively, compared with the Control. These negative effects were primarily aroused by the reduced soil microbial biomass and modified microbial functions (e.g., a decrease in bacteria relative abundance), which could be attributed to N-addition-induced soil acidification and potential phosphorus limitation in this forest. We further found that N additions greatly increased soil-dissolved organic carbon (DOC), and there were significantly negative relationships between microbial biomass and soil DOC, indicating that microbial consumption on soil-soluble carbon pool may decrease. These results suggests that long-term N deposition can increase soil carbon stability and benefit carbon sequestration through decreased carbon mineralization in N-rich tropical forests. This study can help us understand how microbes control soil carbon cycling and carbon sink in the tropics under both elevated N deposition and carbon dioxide in the future.

scholarly journals Climate Dynamics of the Spatiotemporal Changes of Vegetation NDVI in Northern China from 1982 to 2015

2021 ◽  
Vol 13 (2) ◽  
pp. 187
Author(s):  
Rui Sun ◽  
Shaohui Chen ◽  
Hongbo Su
Keyword(s):  
Solar Radiation ◽  
Vegetation Index ◽  
Global Climate ◽  
Regional Scale ◽  
Northern China ◽  
Climate Dynamics ◽  
High Coverage ◽  
Vegetation Growth ◽  
Temperature And Precipitation ◽  
Precipitation And Temperature

As an important part of a terrestrial ecosystem, vegetation plays an important role in the global carbon-water cycle and energy flow. Based on the Global Inventory Monitoring and Modeling System (GIMMS) third generation of Normalized Difference Vegetation Index (NDVI3g), meteorological station data, climate reanalysis data, and land cover data, this study analyzed the climate dynamics of the spatiotemporal variations of vegetation NDVI in northern China from 1982 to 2015. The results showed that growth season NDVI (NDVIgs) increased significantly at 0.006/10a (p < 0.01) in 1982–2015 on the regional scale. The period from 1982 to 2015 was divided into three periods: the NDVIgs increased by 0.026/10a (p < 0.01) in 1982–1990, decreased by −0.002/10a (p > 0.1) in 1990–2006, and then increased by 0.021/10a (p < 0.01) during 2006–2015. On the pixel scale, the increases in NDVIgs during 1982–2015, 1982–1990, 1990–2006, and 2006–2015 accounted for 74.64%, 85.34%, 48.14%, and 68.78% of the total area, respectively. In general, the dominant climate drivers of vegetation growth had gradually switched from solar radiation, temperature, and precipitation (1982–1990) to precipitation and temperature (1990–2015). For woodland, high coverage grassland, medium coverage grassland, low coverage grassland, the dominant climate drivers had changed from temperature and solar radiation, solar radiation and precipitation, precipitation and solar radiation, solar radiation to precipitation and solar radiation, precipitation, precipitation and temperature, temperature and precipitation. The areas controlled by precipitation increased significantly, mainly distributed in arid, sub-arid, and sub-humid areas. The dominant climate drivers for vegetation growth in the plateau climate zone or high-altitude area changed from solar radiation to temperature and precipitation, and then to temperature, while in cold temperate zone, changed from temperature to solar radiation. These results are helpful to understand the climate dynamics of vegetation growth, and have important guiding significance for vegetation protection and restoration in the context of global climate change.

scholarly journals Long-term temperature and precipitation trends at the Coweeta Hydrologic Laboratory, Otto, North Carolina, USA

2012 ◽  
Vol 43 (6) ◽  
pp. 890-901 ◽  
Author(s):  
Stephanie H. Laseter ◽  
Chelcy R. Ford ◽  
James M. Vose ◽  
Lloyd W. Swift
Keyword(s):  
North Carolina ◽  
Global Climate ◽  
Forest Health ◽  
Monitoring Network ◽  
Drought Severity ◽  
Temperature And Precipitation ◽  
Air Temperatures ◽  
Precipitation Record ◽  
Coweeta Hydrologic Laboratory

Coweeta Hydrologic Laboratory, located in western North Carolina, USA, is a 2,185 ha basin wherein forest climate monitoring and watershed experimentation began in the early 1930s. An extensive climate and hydrologic network has facilitated research for over 75 years. Our objectives in this paper were to describe the monitoring network, present long-term air temperature and precipitation data, and analyze the temporal variation in the long-term temperature and precipitation record. We found that over the period of record: (1) air temperatures have been increasing significantly since the late 1970s, (2) drought severity and frequency have increased with time, and (3) the precipitation distribution has become more extreme over time. We discuss the implications of these trends within the context of regional and global climate change and forest health.

scholarly journals The carbon sink of tropical seasonal forests in southeastern Brazil can be under threat

2020 ◽  
Vol 6 (51) ◽  
pp. eabd4548
Author(s):  
Vinícius Andrade Maia ◽  
Alisson Borges Miranda Santos ◽  
Natália de Aguiar-Campos ◽  
Cléber Rodrigo de Souza ◽  
Matheus Coutinho Freitas de Oliveira ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Carbon Sink ◽  
Global Climate ◽  
Carbon Sources ◽  
Southeastern Brazil ◽  
Forest Sites ◽  
Tropical Seasonal Forest ◽  
Terrestrial Carbon Sink ◽  
Seasonal Forests

Tropical forests have played an important role as a carbon sink over time. However, the carbon dynamics of Brazilian non-Amazon tropical forests are still not well understood. Here, we used data from 32 tropical seasonal forest sites, monitored from 1987 to 2020 (mean site monitoring length, ~15 years) to investigate their long-term trends in carbon stocks and sinks. Our results highlight a long-term decline in the net carbon sink (0.13 Mg C ha−1 year−1) caused by decreasing carbon gains (2.6% by year) and increasing carbon losses (3.4% by year). The driest and warmest sites are experiencing the most severe carbon sink decline and have already moved from carbon sinks to carbon sources. Because of the importance of the terrestrial carbon sink for the global climate, policies are needed to mitigate the emission of greenhouse gases and to restore and protect tropical seasonal forests.

scholarly journals Tropical forest primates and logging: long-term coexistence?

Oryx ◽  
1995 ◽  
Vol 29 (3) ◽  
pp. 205-211 ◽  
Author(s):  
Andrew Grieser Johns ◽  
Bettina Grieser Johns
Keyword(s):  
Tropical Forest ◽  
Field Study ◽  
Tropical Forests ◽  
Peninsular Malaysia ◽  
Monitoring Programme ◽  
Long Term Monitoring ◽  
Term Monitoring

Over 10 years ago, Oryx published initial details of an investigation into the effects of selective timber logging on primates in the Sungai Tekam Forestry Concession in peninsular Malaysia (Johns, 1983). This original 2-year field study developed into a long-term monitoring programme, in which the recovery of primates in the regenerating forest is to be recorded throughout the logging cycle. This is the only such monitoring programme so far established in the world's tropical forests. The dataset is now complete for forests logged up to 18 years ago.

scholarly journals What drives the spatial distribution and dynamics of local species richness in tropical forest?

2017 ◽  
Vol 284 (1863) ◽  
pp. 20171503 ◽  
Author(s):  
Thorsten Wiegand ◽  
Felix May ◽  
Martin Kazmierczak ◽  
Andreas Huth
Keyword(s):  
Species Richness ◽  
Tropical Forest ◽  
Temporal Variation ◽  
Tropical Forests ◽  
Temporal Variability ◽  
Dynamic Models ◽  
Neutral Theory ◽  
Spatial And Temporal Variation ◽  
Demographic Stochasticity ◽  
Spatio Temporal

Understanding the structure and dynamics of highly diverse tropical forests is challenging. Here we investigate the factors that drive the spatio-temporal variation of local tree numbers and species richness in a tropical forest (including 1250 plots of 20 × 20 m 2 ). To this end, we use a series of dynamic models that are built around the local spatial variation of mortality and recruitment rates, and ask which combination of processes can explain the observed spatial and temporal variation in tree and species numbers. We find that processes not included in classical neutral theory are needed to explain these fundamental patterns of the observed local forest dynamics. We identified a large spatio-temporal variability in the local number of recruits as the main missing mechanism, whereas variability of mortality rates contributed to a lesser extent. We also found that local tree numbers stabilize at typical values which can be explained by a simple analytical model. Our study emphasized the importance of spatio-temporal variability in recruitment beyond demographic stochasticity for explaining the local heterogeneity of tropical forests.

Tropical Forests in Prehistory, History, and Modernity

2019 ◽  
Author(s):  
Patrick Roberts
Keyword(s):  
Tropical Forest ◽  
Tropical Forests ◽  
Forest Ecosystems ◽  
Global Scale ◽  
Modern World ◽  
Human Adaptation ◽  
Popular Discourse ◽  
Urban Networks ◽  
Human Interactions

In popular discourse, tropical forests are synonymous with 'nature' and 'wilderness'; battlegrounds between apparently pristine floral, faunal, and human communities, and the unrelenting industrial and urban powers of the modern world. It is rarely publicly understood that the extent of human adaptation to, and alteration of, tropical forest environments extends across archaeological, historical, and anthropological timescales. This book is the first attempt to bring together evidence for the nature of human interactions with tropical forests on a global scale, from the emergence of hominins in the tropical forests of Africa to modern conservation issues. Following a review of the natural history and variability of tropical forest ecosystems, this book takes a tour of human, and human ancestor, occupation and use of tropical forest environments through time. Far from being pristine, primordial ecosystems, this book illustrates how our species has inhabited and modified tropical forests from the earliest stages of its evolution. While agricultural strategies and vast urban networks emerged in tropical forests long prior to the arrival of European colonial powers and later industrialization, this should not be taken as justification for the massive deforestation and biodiversity threats imposed on tropical forest ecosystems in the 21st century. Rather, such a long-term perspective highlights the ongoing challenges of sustainability faced by forager, agricultural, and urban societies in these environments, setting the stage for more integrated approaches to conservation and policy-making, and the protection of millennia of ecological and cultural heritage bound up in these habitats.

The relevance of the past unsustainable increase of glacier runoff for large-scale basins in different climatological settings 

2021 ◽  
Author(s):  
Melissa Mengert ◽  
Ben Marzeion
Keyword(s):  
Water Availability ◽  
Large Scale ◽  
Global Climate ◽  
Drainage System ◽  
Mass Change ◽  
Mountain Glaciers ◽  
Temperature And Precipitation ◽  
Long Term Storage ◽  
Seasonal Runoff

&lt;p&gt;Depending on the seasonality of temperature and precipitation, mountain glaciers seasonally store and release large amounts of freshwater. Therefore, glaciers have a strong influence on water availability in many regions of the world. In an ongoing global climate change, glaciers have an additional impact on water availability, as the net amount of stored ice changes in an unsustainable way. This results in glaciers not only altering the seasonal runoff, but also adding a net input into the drainage system.&lt;br&gt;To better understand the interplay between seasonal and long-term storage changes, we suggest to split the monthly seasonal mass balance into a sustainable fraction, which is derived by balancing solid precipitation by ablation proportional to positive temperatures, and an unsustainable fraction, which causes long-term glacier mass change.&lt;/p&gt;&lt;p&gt;Similarly, we consider the effect of glacier area changes, allowing us to separate seasonal runoff into components attributable to (unsustainable) area change, (unsustainable) mass change, or the (sustainable) seasonal runoff from the glacier.&lt;/p&gt;&lt;p&gt;By applying the concept to a reconstruction of global glacier change, we illustrate how the glacier input into river basins in different climatological settings has been affected by the glacier mass loss during the 20th century.&amp;#160;&lt;/p&gt;

scholarly journals Depth-mediated reversal of the effects of climate change on long-term growth rates of exploited marine fish

2007 ◽  
Vol 104 (18) ◽  
pp. 7461-7465 ◽  
Author(s):  
Ronald E. Thresher ◽  
J. A. Koslow ◽  
A. K. Morison ◽  
D. C. Smith
Keyword(s):  
Climate Change ◽  
Deep Water ◽  
Growth Rates ◽  
Global Climate ◽  
Marine Species ◽  
Data Sets ◽  
Otolith Analysis ◽  
Deep Water Species ◽  
Biological Impacts

The oceanographic consequences of climate change are increasingly well documented, but the biological impacts of this change on marine species much less so, in large part because of few long-term data sets. Using otolith analysis, we reconstructed historical changes in annual growth rates for the juveniles of eight long-lived fish species in the southwest Pacific, from as early as 1861. Six of the eight species show significant changes in growth rates during the last century, with the pattern differing systematically with depth. Increasing temperatures near the ocean surface correlate with increasing growth rates by species found in depths <250 m, whereas growth rates of deep-water (>1,000 m) species have declined substantially during the last century, which correlates with evidence of long-term cooling at these depths. The observations suggest that global climate change has enhanced some elements of productivity of the shallow-water stocks but also has reduced the productivity, and possibly the resilience, of the already slow-growing deep-water species.

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