scholarly journals Herbaria as Functional Trait Databases

2018 ◽  
Vol 2 ◽  
pp. e25766 ◽  
Author(s):  
Sofie Meeus
Keyword(s):  
Tree Species ◽  
Functional Trait ◽  
Climatic Conditions ◽  
Congo Basin ◽  
Forest Community ◽  
Herbarium Specimens ◽  
Water Losses ◽  
Climatological Data ◽  
The Impact

Although tropical rainforests play an important role in regulating the world’s climate, they are at the same time particularly vulnerable to changes in the climate. Intense and prolonged droughts, for instance, can lead to biomass loss which will further accelerate these changes. Especially for tree species it becomes problematic, due to their long lifespan, to quickly adapt to or evade unfavorable climatic conditions affecting the composition of the forest community as a whole and consequently the ecosystem services that the rainforests provide. A long-term drying trend currently threatens tropical regions worldwide but is especially strong in the central African rainforest, the second-largest rainforest on Earth. The impact of this decrease in precipitation on the vegetation is, however, still largely unknown due to the limited amount of historical eco-climatological data. Fortunately, these kind of data do exist albeit in a poorly accessible (analog) format in herbarium collections. To investigate if trees show changes in morphology and/or physiology invoked by climatic changes in the last century, the COBECORE team (Congo Basin Eco-Climatological Data Recovery and Valorization”) is exploring the usability of herbaria as potential sources of plant leaf functional trait data using established protocols adjusted to dried leaf material. Photosynthesis as well as gas exchange and transpiration are processes regulated by a plant’s leaves, and depend on the specific leaf area (SLA) and the number and size of the stomata. The less area the latter structures occupy on the leaf the less the plant will suffer from water losses which increases the resistance to drought of plants. We explored the recently digitized African Herbarium of the Botanic Garden Meise which contains over 1.2 million African specimens with a very good coverage of the Congo Basin, dating back to 1880. Currently, we obtained average SLA measurements for 833 herbarium specimens from 59 of the most common tree species of central African rainforests. Pictures for stomata counts and size measurements were taken from over one hundred specimens mainly focused on three Prioria species, giant tree species (up to 60 metres) currently suffering from overexploitation. The data generated in this project will be valuable to understand some lower-level vegetation responses such as plant water use needed to model and predict long-term climate change impacts on vegetation.

Long-term effects of stump removal and tree species composition on the diversity and structure of soil fungal communities

2020 ◽  
Vol 96 (5) ◽  
Author(s):  
Dixi Modi ◽  
Suzanne Simard ◽  
Jean Bérubé ◽  
Les Lavkulich ◽  
Richard Hamelin ◽  
...  
Keyword(s):  
Species Composition ◽  
Fungal Community ◽  
Tree Species ◽  
Management Practice ◽  
Tree Regeneration ◽  
Root Disease ◽  
Fungal Communities ◽  
Tree Species Composition ◽  
The Impact

ABSTRACT Stump removal is a common forest management practice used to reduce the mortality of trees affected by the fungal pathogen-mediated root disease, Armillaria root rot, but the impact of stumping on soil fungal community structure is not well understood. This study analyzed the long-term impact of stumping and tree species composition on the abundance, diversity and taxonomic composition of soil fungal communities using internal transcribed spacer (ITS) marker-based DNA metabarcoding in a 48-year-old trial at Skimikin, British Columbia. A total of 108 samples were collected from FH (fermented and humus layers), and soil mineral horizons (A and B) from stumped and unstumped plots of six tree species treatments (pure stands and admixtures of Douglas-fir, western red-cedar and paper birch). Fungal α-diversity in the A horizon significantly increased with stumping regardless of tree species composition, while β-diversity was significantly affected by stumping in all the horizons. We also observed that the relative abundance of the saprotrophic fungal community declined while that of the ectomycorrhizal fungal community increased with stumping. In conclusion, increase in ectomycorrhizal fungal associations, which are positively associated with tree productivity, suggests that stumping can be considered a good management practice for mitigating root disease and promoting tree regeneration.

DOES HARMFUL CLIMATE INCREASE OR DECREASE MIGRATION? EVIDENCE FROM RURAL HOUSEHOLDS IN NIGERIA

2019 ◽  
Vol 10 (04) ◽  
pp. 1950013
Author(s):  
CRISTINA CATTANEO ◽  
EMANUELE MASSETTI
Keyword(s):  
Climate Change ◽  
Adaptation Strategy ◽  
Climatic Conditions ◽  
Marginal Effect ◽  
Cross Sectional ◽  
Temperature Changes ◽  
And Migration ◽  
Migrant Households ◽  
The Impact

This paper analyzes whether migration is an adaptation strategy that households employ to cope with climate in Nigeria. We estimate our model using the cross-sectional variation in climate and long-term migration decisions because we are interested in the average response to long-term climatic conditions. For households that operate farms, we find that the relationship between climate and migration is nonlinear. In particular, climates closer to ideal farming conditions are associated with a higher propensity to migrate, whereas in the least favorable climatic conditions, the propensity to migrate declines. The marginal effect of rainfall and temperature changes on migration varies by season. We estimate the impact of climate change on the number of migrant households in 2031–2060 and 2071–2100, ceteris paribus. With current population levels, climate change generates between 3.6 and 6.3 million additional migrants, most of them being internal. However, these estimates are not statistically significant.

scholarly journals How Can Litter Modify the Fluxes of CO2 and CH4 from Forest Soils? A Mini-Review

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1276
Author(s):  
Anna Walkiewicz ◽  
Adrianna Rafalska ◽  
Piotr Bulak ◽  
Andrzej Bieganowski ◽  
Bruce Osborne
Keyword(s):  
Climate Change ◽  
Forest Soils ◽  
Tree Species ◽  
Water Movement ◽  
C Sequestration ◽  
Climatic Conditions ◽  
Tree Species Composition ◽  
Clear Cutting ◽  
And Shifts ◽  
The Impact

Forests contribute strongly to global carbon (C) sequestration and the exchange of greenhouse gases (GHG) between the soil and the atmosphere. Whilst the microbial activity of forest soils is a major determinant of net GHG exchange, this may be modified by the presence of litter through a range of mechanisms. Litter may act as a physical barrier modifying gas exchange, water movement/retention and temperature/irradiance fluctuations; provide a source of nutrients for microbes; enhance any priming effects, and facilitate macro-aggregate formation. Moreover, any effects are influenced by litter quality and regulated by tree species, climatic conditions (rainfall, temperature), and forest management (clear-cutting, fertilization, extensive deforestation). Based on climate change projections, the importance of the litter layer is likely to increase due to an litter increase and changes in quality. Future studies will therefore have to take into account the effects of litter on soil CO2 and CH4 fluxes for various types of forests globally, including the impact of climate change, insect infestation, and shifts in tree species composition, as well as a better understanding of its role in monoterpene production, which requires the integration of microbiological studies conducted on soils in different climatic zones.

scholarly journals Economic-Engineering Modelling of the Buildings Sector to Study the Transition towards Deep Decarbonisation in the EU

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2745 ◽  
Author(s):  
Fotiou ◽  
Vita ◽  
Capros
Keyword(s):  
Energy Efficiency ◽  
Electric Heating ◽  
Heat Pumps ◽  
Climatic Conditions ◽  
Mathematical Framework ◽  
The European Union ◽  
The Cost ◽  
The Impact ◽  
The Eu

The paper presents a newly developed economic-engineering model of the buildings sector and its implementation for all the European Union (EU) Member States (MS), designed to study in detail ambitious energy efficiency strategies and policies, in the context of deep decarbonisation in the long term. The model has been used to support the impact assessment study that accompanied the European Commission’s communication “A Clear Planet for All”, in November 2018. The model covers all EU countries with a fine resolution of building types, and represents agent decision-making in a complex and dynamic economic-engineering mathematical framework. Emphasis is given to behaviours driving the energy renovation of buildings and the ensuing choice of equipment for heating and cooling. The model represents several market and non-market policies that can influence energy decisions in buildings and promote deep energy renovation. Moreover, the paper presents key applications for supporting policies targeting ambitious reduction of energy consumption and carbon emissions in buildings across Europe. The results illustrate that the achievement of ambitious energy-efficiency targets in the long-term heavily depends on pursuing a fast and extensive renovation of existing buildings, at annual rates between 1.21% and 1.77% for the residential sector and between 0.92% to 1.35% for the services sector. In both cases, the renovation rates are far higher past trends. Strong policies aimed at removing non-market barriers are deemed necessary. Electrification constitutes a reasonable choice for deeply renovated buildings and, as a result, almost 50% of households chooses electric heating over gas heating in the long term. However, heat pumps need to exploit further their learning potential to be economical and implementable for the various climatic conditions in Europe. The results also show that the cost impacts are modest even if renovation and decarbonisation in buildings develop ambitiously in the EU. The reduced energy bills due to energy savings can almost offset the increasing capital expenditures. Fundraising difficulties and the cost of capital are, however, of concern.

Pesticide Runoff from Paddy Field and Its Impact on Receiving Water

1992 ◽  
Vol 25 (11) ◽  
pp. 69-76 ◽  
Author(s):  
S. Li ◽  
J. Migita
Keyword(s):  
Paddy Field ◽  
Evaluation System ◽  
Cultural Practices ◽  
Chemical Properties ◽  
Climatic Conditions ◽  
Dynamic Factors ◽  
Pesticide Runoff ◽  
The Impact ◽  
Pesticide Usage

A mathematical model is developed to predict the runoff of pesticides from paddy field to a river. The model describes the long term runoff as a function of physical-chemical properties of pesticides, cultural practices and climatic conditions. It is assumed that the adsorption and desorption of pesticides between soil and water phases are in equilibrium state, while the degradation in water and soil and the evaporation from water to atmosphere are of first-order reaction. The model is used to examine the relationships between the seasonal amounts of pesticide runoff and their environmental dynamic factors. A four-stage evaluation system is proposed to assess the impact of the runoff on drinking water by taking into account the amount of application, runoff ratio, toxicity and the possibility of being removed from raw water by water purification processes. The model simulates the daily variation of contaminant level in river water, thereby providing a basis for making recommendations for pesticide usage and water management for rice cultivation.

scholarly journals Effects of Cooling Systems on Greenhouse Microclimate and Cucumber Growth under Mediterranean Climatic Conditions

Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 300 ◽  
Author(s):  
Georgios Nikolaou ◽  
Damianos Neocleous ◽  
Nikolaos Katsoulas ◽  
Constantinos Kittas
Keyword(s):  
Vapor Pressure Deficit ◽  
Cooling System ◽  
Ventilation System ◽  
Climatic Conditions ◽  
Irrigation Regime ◽  
Crop Water ◽  
Water Losses ◽  
Cooling Systems ◽  
Cropping Seasons ◽  
The Impact

Two experiments were conducted in different cropping seasons under Mediterranean climatic conditions to investigate the impact of two cooling systems (fan-pad evaporative as opposed to fan ventilation) on greenhouse microclimate and soilless cucumber growth. The second objective of the experiment was to determine the most appropriate irrigation regime (between 0.24 and 0.32 L m−2) in relation to crop water uptake and greenhouse fertigation effluents. The use of a fan ventilation system enhanced the vapor pressure deficit; thus, the crop transpiration improved by 60% in relation to the transpiration rates of plants grown under the fan-pad system. Higher transpiration rates alleviated the heat load as the external–inside greenhouse air differences declined from 6.2 °C to 3 °C. The leaf–air temperature differential indicated that plants were not facing any water stress conditions for both cooling systems tested; however, fan ventilation reduced drainage emissions outflows (95% decrease) compared with evaporative cooling. Results also demonstrated that an irrigation regime of 0.24 L m−2 can be applied successfully in soilless cucumber crops, keeping the drainage to a minimum (20% of the nutrient solution supply). These results suggest that fan ventilation cooling system in conjugation with an appropriate irrigation regime prevents overheating and minimizes the nutrient and water losses in spring-grown soilless cucumber crops in Mediterranean greenhouses without compromising yield.

scholarly journals Historical Aerial Surveys Map Long-Term Changes of Forest Cover and Structure in the Central Congo Basin

2020 ◽  
Vol 12 (4) ◽  
pp. 638 ◽  
Author(s):  
Koen Hufkens ◽  
Thalès de Haulleville ◽  
Elizabeth Kearsley ◽  
Kim Jacobsen ◽  
Hans Beeckman ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Forest Cover ◽  
Congo Basin ◽  
Spatial And Temporal Patterns ◽  
Smallholder Farming ◽  
Aboveground Carbon ◽  
Decadal Scale ◽  
Long Term Changes ◽  
The Impact

Given the impact of tropical forest disturbances on atmospheric carbon emissions, biodiversity, and ecosystem productivity, accurate long-term reporting of Land-Use and Land-Cover (LULC) change in the pre-satellite era (<1972) is an imperative. Here, we used a combination of historical (1958) aerial photography and contemporary remote sensing data to map long-term changes in the extent and structure of the tropical forest surrounding Yangambi (DR Congo) in the central Congo Basin. Our study leveraged structure-from-motion and a convolutional neural network-based LULC classifier, using synthetic landscape-based image augmentation to map historical forest cover across a large orthomosaic (~93,431 ha) geo-referenced to ~4.7 ± 4.3 m at submeter resolution. A comparison with contemporary LULC data showed a shift from previously highly regular industrial deforestation of large areas to discrete smallholder farming clearing, increasing landscape fragmentation and providing opportunties for substantial forest regrowth. We estimated aboveground carbon gains through reforestation to range from 811 to 1592 Gg C, partially offsetting historical deforestation (2416 Gg C), in our study area. Efforts to quantify long-term canopy texture changes and their link to aboveground carbon had limited to no success. Our analysis provides methods and insights into key spatial and temporal patterns of deforestation and reforestation at a multi-decadal scale, providing a historical context for past and ongoing forest research in the area.

Long-term changes in tree species composition in the Dinaric mountain forests of Slovenia

2003 ◽  
Vol 79 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Andrej Boncina ◽  
Franc Gaspersic ◽  
Jurij Diaci
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
European Beech ◽  
Anthropogenic Factors ◽  
Silver Fir ◽  
Tree Species Composition ◽  
Virgin Forest ◽  
Forest Remnant ◽  
The Impact

This study utilizes data from long-term research sites in managed fir-beech forests (Hrusica, Leskova dolina and Rog) and a virgin forest remnant (Rajhenav), used as a reference site. Data obtained from old forest management plans and forest inventories were analysed. The results of the study support the hypothesis that two main tree species—silver fir (Abies alba Mill.) and European beech (Fagus sylvatica L.)—alternate site dominance. The causes of species dominance alternation include both natural processes and anthropogenic factors, in particular silvicultural practices and the impact of ungulates. More than a hundred years ago, European beech dominated stand volume. The proportion of silver fir increased until 1940–1970 when a gradual decrease started. All indicators suggest that the proportion of silver fir will decrease further in the coming decades. Key words: tree species composition alternation, diameter distribution, silver fir, European beech, forest history, forest planning, managed forests, virgin forest remnant

Phenology and stem-growth periodicity of tree species in Amazonian floodplain forests

2002 ◽  
Vol 18 (4) ◽  
pp. 581-597 ◽  
Author(s):  
Jochen Schöngart ◽  
Maria Teresa F. Piedade ◽  
Sabine Ludwigshausen ◽  
Viviana Horna ◽  
Martin Worbes
Keyword(s):  
Tree Species ◽  
Deciduous Forest ◽  
Water Status ◽  
Strong Relationship ◽  
Flood Pulse ◽  
Stem Diameter ◽  
Diameter Growth ◽  
Periodic Behaviour ◽  
The Impact

To study the impact of the annual long-term flooding (flood-pulse) on seasonal tree development in Amazonian floodplains, the phenology and growth in stem diameter of various tree species with different leaf-change patterns were observed over a period of 2 y. The trees of the functional ecotypes, evergreen, brevi-deciduous, deciduous and stem-succulent showed a periodic behaviour mainly triggered by the flood-pulse. Trees have high increment during the terrestrial phase. Flooding causes a shedding of some or all leaves leading to a cambial dormancy of about 2 mo and the formation of an annual ring. Studies carried out in tropical dry forests verify a strong relationship between the phenological development and the water status of the trees, strongly affected by seasonal drought. The comparison of the phenology and the diameter growth of the corresponding ecotypes in floodplain forest and a semi-deciduous forest in Venezuela shows a displacement of at least 2 mo in the periodicity, except for stem-succulent tree species. For stem-succulent trees it remains unclear which factors influence phenology and stem diameter growth.

Core aspects of international water supply and wastewater disposal with a focus on developing countries in the Asia and Africa region

2019 ◽  
Vol 19 (6) ◽  
pp. 1809-1815 ◽  
Author(s):  
M. Lawens ◽  
H. Eckhardt ◽  
S. Gramel
Keyword(s):  
Developing Countries ◽  
Water Supply ◽  
Water Reuse ◽  
Developed Countries ◽  
Climatic Conditions ◽  
Anaerobic Sludge ◽  
Water Losses ◽  
Wastewater Disposal ◽  
Untreated Wastewater ◽  
The Impact

Abstract Water crises are already stressing societies, economies, and the environment worldwide and especially developing countries. The expected growth in population, urbanization and economic activity, as well as the impact of climate change, will exacerbate the situation in the coming decade. In developed countries, conventional water supply and wastewater disposal systems ensure safe access to drinking water, sanitation and wastewater services. The worldwide application of conventional systems is, however, only possible to a limited extent. The reason for this is that these systems are designed for certain climatic conditions and also do not consider the varying requirements regarding water supply and wastewater disposal typical for developing countries. Although there are alternative water supply and wastewater disposal systems that have proved to be successful throughout the developing world, there are still several barriers to their worldwide adoption. To increase the establishment of these approaches this paper focuses on aspects of particular relevance for developing countries, namely: water reuse (untreated wastewater), alternative sewerage (settled and simplified sewerage), alternative wastewater treatment (waste stabilization ponds, constructed wetlands and up-flow anaerobic sludge blanket reactors) and management of water losses (real and apparent losses).

Sign in / Sign up

Export Citation Format

Share Document