Tropical secondary forests

1990 ◽  
Vol 6 (1) ◽  
pp. 1-32 ◽  
Author(s):  
Sandra Brown ◽  
Ariel E. Lugo
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Net Primary Productivity ◽  
Secondary Forest ◽  
Ground Vegetation ◽  
Litter Production ◽  
Secondary Forests ◽  
Forest Lands ◽  
The Tropics ◽  
The Impact

ABSTRACTThe literature on tropical secondary forests, defined as those resulting from human disturbance (e.g. logged forests and forest fallows), is reviewed to address questions related to their extent, rates of formation, ecological characteristics, values and uses to humans, and potential for management. Secondary forests are extensive in the tropics, accounting for about 40% of the total forest area and their rates of formation are about 9 million ha yr−1. Geographical differences in the extent, rates of formation and types of forest being converted exist.Secondary forests appear to accumulate woody plant species at a relatively rapid rate but the mechanisms involved are complex and no clear pattern emerged. Compared to mature forests, the structure of secondary forest vegetation is simple, although age, climate and soil type are modifying factors. Biomass accumulates rapidly in secondary forests, up to 100 t ha−1 during the first 15 yr or so, but history of disturbance may modify this trend. Like biomass, high rates of litter production are established relatively quickly, up to 12–13 t ha−1 yr−1 by age 12–15 yr. And, in younger secondary forests (< 20 yr), litter production is a higher fraction of the net primary productivity than stemwood biomass production. More organic matter is pro duced and transferred to the soil in younger secondary forests than is stored in above-ground vegetation. The impact of this on soil organic matter is significant and explains why the recovery of organic matter in the soil under secondary forests is relatively fast (50 yr or so). Nutrients are accumulated rapidly in secondary vegetation, and are returned quickly by litterfall and decomposition for uptake by roots.We propose a model of the gains and losses, yields and costs, and benefits and tradeoffs to people from the current land-use changes occurring in the tropics. When the conversion of forest lands to secondary forests and agriculture is too fast or land-use stages are skipped, society loses goods and services. To avoid such a loss, we advocate management of tropical forest lands within a landscape perspective, a possibility in the tropics because land tenures and development projects are often large.

Bewirtschaftung von tropischen Sekundärwäldern

2002 ◽  
Vol 46 (1) ◽  
Author(s):  
Dietrich Schmidt-Vogt
Keyword(s):  
Land Use ◽  
Forest Cover ◽  
Stand Structure ◽  
Secondary Forest ◽  
Secondary Forests ◽  
Tropical Asia ◽  
Land Use Systems ◽  
The Future ◽  
The Tropics ◽  
Primary Forests

AbstractManagement of secondary tropical forests: a new perspective for sustainable use of forests in Asia. The decline of primary forests in the tropics is leading to a reassessment of the role secondary forests might play within the context of tropical forest management. Recent research has shown that secondary forests in the tropics can be both rich in species and complex in terms of stand structure. There is, moreover, a growing recognition of the importance of secondary forests for traditional subsistence economies in the tropics and of their economic potential for land use systems in the future. Management of secondary forests in Asia as an alternative to the extraction of timber from primary forests but also as one among other options to intensify traditional land use systems has a potential for the future especially because of the existence of vast tracts of valuable secondary forest cover, and because of the store of traditional knowledge that can still be found in tropical Asia.

Vegetation Effects on Soil Properties in the Monteagle Sandy Loam Series: Implications for Land‐use Change

2017 ◽  
Author(s):  
Allison Neil
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Land Use Change ◽  
Soil Properties ◽  
Soil Carbon ◽  
Sugar Maple ◽  
Agricultural Land ◽  
Deciduous Forest ◽  
Coniferous Forest ◽  
The Impact

Soil properties are strongly influenced by the composition of the surrounding vegetation. We investigated soil properties of three ecosystems; a coniferous forest, a deciduous forest and an agricultural grassland, to determine the impact of land use change on soil properties. Disturbances such as deforestation followed by cultivation can severely alter soil properties, including losses of soil carbon. We collected nine 40 cm cores from three ecosystem types on the Roebuck Farm, north of Perth Village, Ontario, Canada. Dominant species in each ecosystem included hemlock and white pine in the coniferous forest; sugar maple, birch and beech in the deciduous forest; grasses, legumes and herbs in the grassland. Soil pH varied little between the three ecosystems and over depth. Soils under grassland vegetation had the highest bulk density, especially near the surface. The forest sites showed higher cation exchange capacity and soil moisture than the grassland; these differences largely resulted from higher organic matter levels in the surface forest soils. Vertical distribution of organic matter varied greatly amongst the three ecosystems. In the forest, more of the organic matter was located near the surface, while in the grassland organic matter concentrations varied little with depth. The results suggest that changes in land cover and land use alters litter inputs and nutrient cycling rates, modifying soil physical and chemical properties. Our results further suggest that conversion of forest into agricultural land in this area can lead to a decline in soil carbon storage.

scholarly journals Emissions of Nitrous Oxide and Nitric Oxide from Soils of Native and Exotic Ecosystems of the Amazon and Cerrado Regions of Brazil

2001 ◽  
Vol 1 ◽  
pp. 312-319 ◽  
Author(s):  
Eric A. Davidson ◽  
Mercedes M.C. Bustamante ◽  
Alexandre de Siqueira Pinto
Keyword(s):  
Nitric Oxide ◽  
Land Use ◽  
Nitrous Oxide ◽  
Photochemical Reactions ◽  
N2o Emissions ◽  
Secondary Forests ◽  
Soil Emissions ◽  
Amazonian Forests ◽  
The Impact ◽  
No Emissions

This paper reviews reports of nitrous oxide (N2O) and nitric oxide (NO) emissions from soils of the Amazon and Cerrado regions of Brazil. N2O is a stable greenhouse gas in the troposphere and participates in ozone-destroying reactions in the stratosphere, whereas NO participates in tropospheric photochemical reactions that produce ozone. Tropical forests and savannas are important sources of atmospheric N2O and NO, but rapid land use change could be affecting these soil emissions of N oxide gases. The five published estimates for annual emissions of N2O from soils of mature Amazonian forests are remarkably consistent, ranging from 1.4 to 2.4 kg N ha–1 year–1, with a mean of 2.0 kg N ha–1 year–1. Estimates of annual emissions of NO from Amazonian forests are also remarkably similar, ranging from 1.4 to 1.7 kg N ha–1 year–1, with a mean of 1.5 kg N ha–1 year–1. Although a doubling or tripling of N2O has been observed in some young (<2 years) cattle pastures relative to mature forests, most Amazonian pastures have lower emissions than the forests that they replace, indicating that forest-topasture conversion has, on balance, probably reduced regional emissions slightly (<10%). Secondary forests also have lower soil emissions than mature forests. The same patterns apply for NO emissions in Amazonia. At the only site in Cerrado where vegetation measurements have been made N2O emissions were below detection limits and NO emissions were modest (~0.4 kg N ha–1 year–1). Emissions of NO doubled after fire and increased by a factor of ten after wetting dry soil, but these pulses lasted only a few hours to days. As in Amazonian pastures, NO emissions appear to decline with pasture age. Detectable emissions of N2O have been measured in soybean and corn fields in the Cerrado region, but they are modest relative to fluxes measured in more humid tropical agricultural regions. No measurements of NO from agricultural soils in the Cerrado region have been made, but we speculate that they could be more important than N2O emissions in this relatively dry climate. While a consistent pattern is emerging from these studies in the Amazon region, far too few data exist for the Cerrado region to assess the impact of land use changes on N oxide emissions.

scholarly journals FOREST CERTIFICATION AS A TOOL TO ENSURE THE BALANCE OF FORESTRY LAND USE

2021 ◽  
Vol 71 (3) ◽  
Author(s):  
Stepan Dankevych
Keyword(s):  
Land Use ◽  
Regional Scale ◽  
Environmental Indicators ◽  
Statistical Characteristics ◽  
Forest Certification ◽  
Capital Investments ◽  
Forest Lands ◽  
The Impact ◽  
The Relationship ◽  
Over Time

The problem of ensuring the balanced use of forest lands determines the search for new economic and environmental tools that can influence this process. The need to improve the certification tool as part of the financial and economic mechanism for ensuring balanced forestry land use corresponds to the directions of state policy and European integration intentions of Ukraine, modern requirements of the ecological aspect of forestry land use. The work examines the practice in the field of forest certification in Ukraine from the point of view of balanced land use. Spatial-temporal analysis and assessment of the scale and dynamics of the spread of forest FSC certification in Ukraine has been carried out. The study was formed in three stages: (I) study of changes over time in the volume of forest certification on a national scale, (II) assessment of trends over time for indicators on a regional scale, (III) study of the relationship between individual indicators. The analysis of the impact of FSC-certification of forest management in Ukraine on the environmental indicators of forestry land use based on the results of the correlation between the statistical characteristics of certain economic and environmental indicators, such as the area of certified forests, capital investments, reforestation. Analysis of statistical data showed the relationship between environmental and economic performance over time and changes in specific characteristics on a regional scale. The study makes it possible, on the basis of an objectively existing causal relationship between phenomena and indicators, to identify the course of certain positive or negative processes in forestry land use. Forest certification can play a role in maintaining a balanced use of forest lands, preventing illegal logging, forest degradation and contributing to reforestation and capital investments. The study helps to identify certain key variables that limit the ability of forestry operators to ensure balanced use of forest lands and how forest certification can affect this. Foreign experience in stimulating forest certification has been investigated for the possibility of borrowing the experience of using management tools in order to motivate forest certification in Ukraine. It has been proven that certification is a significant environmental tool for ensuring a balanced level of land use and has the potential for further development.

scholarly journals Land use influences stream bacterial communities in lowland tropical watersheds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karina A. Chavarria ◽  
Kristin Saltonstall ◽  
Jorge Vinda ◽  
Jorge Batista ◽  
Megan Lindmark ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Bacterial Communities ◽  
Secondary Forest ◽  
Stream Water ◽  
Community Diversity ◽  
Forested Catchments ◽  
Unifrac Distance ◽  
Cattle Pasture ◽  
The Impact

AbstractLand use is known to affect water quality yet the impact it has on aquatic microbial communities in tropical systems is poorly understood. We used 16S metabarcoding to assess the impact of land use on bacterial communities in the water column of four streams in central Panama. Each stream was influenced by a common Neotropical land use: mature forest, secondary forest, silvopasture and traditional cattle pasture. Bacterial community diversity and composition were significantly influenced by nearby land uses. Streams bordered by forests had higher phylogenetic diversity (Faith’s PD) and similar community structure (based on weighted UniFrac distance), whereas the stream surrounded by traditional cattle pasture had lower diversity and unique bacterial communities. The silvopasture stream showed strong seasonal shifts, with communities similar to forested catchments during the wet seasons and cattle pasture during dry seasons. We demonstrate that natural forest regrowth and targeted management, such as maintaining and restoring riparian corridors, benefit stream-water microbiomes in tropical landscapes and can provide a rapid and efficient approach to balancing agricultural activities and water quality protection.

Financial compensation and uncertainty: using mean-variance rule and stochastic dominance to derive conservation payments for secondary forests

2008 ◽  
Vol 38 (12) ◽  
pp. 3033-3046 ◽  
Author(s):  
Thomas Knoke ◽  
Patrick Hildebrandt ◽  
Daniel Klein ◽  
Rodrigo Mujica ◽  
Martin Moog ◽  
...  
Keyword(s):  
Land Use ◽  
Decision Maker ◽  
Secondary Forest ◽  
Distribution Functions ◽  
Cumulative Distribution ◽  
Opportunity Costs ◽  
Secondary Forests ◽  
Financial Compensation ◽  
Systematic Risks ◽  
Mean Variance

The expected opportunity costs of conserving a specific land use are usually considered adequate as financial compensation. However, a “conservation premium” is sometimes proposed as an added incentive, i.e., compensation greater than the expected opportunity costs. This paper discusses various methodological opportunities for deriving effective compensation under uncertainty. Based on cumulative distribution functions of possible opportunity costs (a Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) plantation was considered the alternative to conserving a Chilean secondary forest), generated through Monte Carlo simulations, we derived an inclusive range of possible compensations from 77 up to 375 US$·ha–1·year–1. If we assumed that the two land-use alternatives were mutually exclusive and independent from other risky investments, a compensation of 375 US$·ha–1·year–1 was necessary to convince every decision maker to maintain the secondary forest. However, only 77 US$·ha–1·year–1 was enough for a risk-averse decision maker (given average opportunity costs of 113 US$·ha–1·year–1). Yet, it turned out that the greatest possible opportunity costs would already be compensated for with 199 US$·ha–1·year–1, given an error probability of 0.05. Compensating for the last 5% of possible opportunity costs would thus require an additional 176 US$·ha–1·year–1. Our approach had two main limitations, namely we did not consider portfolio effects, which would allow diversifying away unsystematic risks, and we did not take into account the different systematic risks of the compared alternatives. These limitations may have led to an overestimation of effective compensation.

scholarly journals Transformation of Lowland Rainforest into Oil-palm Plantations and use of Fire alter Topsoil and Litter Silicon Pools and Fluxes

Silicon ◽  
2020 ◽  
Author(s):  
Barbara von der Lühe ◽  
Laura Pauli ◽  
Britta Greenshields ◽  
Harold J. Hughes ◽  
Aiyen Tjoa ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Oil Palm ◽  
Fire Event ◽  
Oil Palm Frond ◽  
Lowland Rainforest ◽  
The Impact ◽  
Effects Of Land Use ◽  
Palm Frond

Abstract The effects of land use and fire on ecosystem silicon (Si) cycling has been largely disregarded so far. We investigated the impacts of land use and fire on Si release from topsoils and litter of lowland rainforest and oil-palm plantations in Jambi Province, Indonesia. Lower concentrations of Si in amorphous silica (ASi) were found in oil-palm plantation topsoils (2.8 ± 0.7 mg g− 1) compared to rainforest (3.5 ± 0.8 mg g− 1). Higher total Si concentrations were detected in litter from oil-palm frond piles (22.8 ± 4.6 mg g− 1) compared to rainforest litter (12.7 ± 2.2 mg g− 1). To test the impact of fire, materials were burned at 300 °C and 500 °C and were shaken with untreated samples in simulated rainwater for 28 h. Untreated oil-palm topsoils showed a significantly lower Si release (p≤ 0.05) compared to rainforest. The fire treatments resulted in an increased Si release into simulated rainwater. Si release from oil-palm topsoils and litter increased by a factor of 6 and 9 (500 °C), respectively, and Si release from rainforest topsoils and litter by a factor of 3 and 9 (500 °C). Differences between land use were related to initial ASi and litter Si concentrations, and to losses of soil organic matter during burning. We conclude that transformation of rainforest into oil palm plantations could be an important and immediate Si source after a fire event but may indirectly lead to a decrease in the long-term Si availability to plants.

Land use change in Amazonian Dark Earth and Acrisol: Responses of organic carbon, organic matter composition and microbial carbon utilisation

2020 ◽  
Author(s):  
Klaus Jarosch ◽  
Luis Carlos Colocho Hurtarte ◽  
Konstantin Gavazov ◽  
Aleksander Westphal Muniz ◽  
Christoph Müller ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Community Structure ◽  
Microbial Community ◽  
Organic Carbon ◽  
Land Use Change ◽  
Microbial Community Structure ◽  
Secondary Forest ◽  
Soil Types ◽  
Amazonian Dark Earth

&lt;p&gt;The conversion of tropical forest for cassava cultivation is widely known to decrease the soil organic matter (OM) and nutrient contents of highly weathered soils in the tropics. Amazonian Dark Earth (ADE) might be affected less due to their historical anthropogenic amelioration with e.g. charcoal, ceramics and bones, leading to higher soil OM and nutrient concentrations. In this study, we analysed the effect of land use change on the OM dynamics and its composition under tropical conditions, using ADE and an adjacent Acrisol (ACR) as model systems. Soil samples were obtained south of Manaus (Brazil), from a secondary forest and an adjacently located 40-year-old cassava plantation. The land use change induced a severe decrease of organic carbon (OC) concentrations in ADE (from 35 to 15&amp;#160;g&amp;#160;OC&amp;#160;kg&lt;sup&gt;&amp;#8209;1&lt;/sup&gt;) while OC in the adjacent ACR was less affected (18 to 16&amp;#160;g&amp;#160;OC&amp;#160;kg&lt;sup&gt;&amp;#8209;1&lt;/sup&gt;). Soils were analysed by &lt;sup&gt;13&lt;/sup&gt;C NMR spectroscopy to obtain information on how the conversion of secondary forest to cassava affected the chemical composition of OM. Our results show that land use change induces differences in the OM composition: The OM in ADE changes to a more decomposed state (increase of alkyl:O/N-alkyl ratio) whereas the OM in ACR changes to a less decomposed state (decrease of alkyl:O/N-alkyl ratio). According to a molecular mixing model, land use change influenced mostly the proportion of lipids, which might be related with a change of the plant input. The incubation of the soils with &lt;sup&gt;13&lt;/sup&gt;C glucose enabled resolving how soil microorganisms were affected by land use change. In both soil types ADE and ACR, land use change caused a reduction of the total &lt;sup&gt;13&lt;/sup&gt;C glucose respiration by approximately one third in a 7-days incubation, implying lower microbial activity. Microorganisms in both soil types appear to be more readily active in soils under forest, since we observed a distinct lag time between &lt;sup&gt;13&lt;/sup&gt;C glucose addition and respiration under cassava planation. This indicated differences in microbial community structure, which we will assess further by determining the &lt;sup&gt;13&lt;/sup&gt;C label uptake by the microbial biomass and the microbial community structure using &lt;sup&gt;13&lt;/sup&gt;C PLFA analysis. Preliminary results from synchrotron-based STXM demonstrate a distinct arrangement of OM at fine-sized charcoal-particle interfaces. Samples of soils receiving &lt;sup&gt;13&lt;/sup&gt;C label will be further analysed by NanoSIMS with the hypothesis that charcoal interfaces foster nutrient dynamics at the microscale. Despite the high loss of OC in the ameliorated ADE through land use change, the remaining OM might improve the nutrient availability thanks to charcoal interactions compared to the ACR. Our results contribute to a better understanding of the sensitivity of OM upon land use change and how the microbial community is responding to land use change in highly weathered tropical soils.&lt;/p&gt;

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