scholarly journals High Recovery of Saplings after Severe Drought in Temperate Deciduous Forests

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 546 ◽  
Author(s):  
Mirela Beloiu ◽  
Reinhold Stahlmann ◽  
Carl Beierkuhnlein

Drought episodes are predicted to increase their intensity and frequency globally, which will have a particular impact on forest vitality, productivity, and species distribution. However, the impact of tree species interaction on forest vulnerability to drought is not yet clear. This study aims to assess how deciduous saplings react to drought and whether tree species diversity can buffer the impact of drought stress on tree saplings. Based on field measurements of crown defoliation and species diversity, vulnerability, drought recovery, and species interaction were analyzed. Fieldwork was carried out in Central Eastern Germany in 2018 during the vegetation season and repeated in 2019. Ten random saplings were measured in each of the 218 plots (15 × 15 m) with 2051 saplings in total out of 41 tree species. We found that 65% of the saplings experienced defoliation during the drought of 2018, of which up to 13% showed complete defoliation. At the species level, Fagus sylvatica L. and Betula pendula Roth. saplings were less affected (<55%), whereas Carpinus betulus L., Sorbus aucuparia L., and Frangula alnus Mill. saplings were the most affected (≥85%). One year later, in 2019, C. betulus and S. aucuparia had a faster recovery rate than F. sylvatica, B. pendula, Quercus spp., and Crataegus spp. (p < 0.001). Furthermore, we showed that forest stands with high sapling species diversity had a reduced vitality under drought stress (p < 0.001), indicating a higher competition for resources. The study provides evidence that F. sylvatica saplings can withstand and survive to persistent drought. Species-specific responses to drought are essential to be considered for implementing adaptive forest management strategies to mitigate the impact of climate change.

2019 ◽  
Vol 42 (2) ◽  
pp. 185-190
Author(s):  
Shephali Sachan ◽  
◽  
Avinash Jain ◽  

Drought stress is creating dangerous situation worldwide. The impact of stress is not only the deficiency of water but it also leads to the deficiency and losses of everything which are linked to the water resources directly or indirectly. Drought stress disturbs the normal biochemical, molecular and physiological processes, affecting the morphology of plant. As a result the plant is either unable to live on abrupt changes or learn to avoid/tolerate the variation in the environment. The results vary species to species depending on genotype, frequency and time period of drought stress. There is need of screening various tree species for getting information related to their ability and capacity level of susceptibility, tolerance and avoidance behaviour with the further goal of their plantation in the various nurseries in order to rehabilitate the drought prone areas, wastelands and to increase intangible and tangible benefits.


2021 ◽  
Vol 14 (2) ◽  
pp. 16-23
Author(s):  
Kinjouo Ghislain Kenguem ◽  
Victor François Nguetsop ◽  
Solefack Marie Caroline Momo

Les forêts d’Afrique centrale contiennent plusieurs produits d’origine animale et végétale. Les produits d’origine végétale peuvent se distinguer en produits forestiers ligneux et non ligneux. Le présent travail de recherche porte sur l’importance et la gestion durable de quelques Produits Forestiers Non Ligneux (PFNL), notamment l’écorce de trois arbres (Garcinia lucida, Scorodophloeus zenkeri, Alstonia boonei) dans la localité de Ngovayang I. À l’aide d’un questionnaire semi-structuré, les caractéristiques du secteur des PFNL, les stratégies de gestion, ainsi que l’impact de la valorisation des PFNL ont été déterminés. Il ressort des enquêtes que les écorces de ces trois espèces sont connues et utilisées à des fins diverses telles que la consommation, l’automédication et la vente. L’initiation à l’utilisation de l’écorce de ces espèces est liée au sexe et est également fonction de l’âge des enquêtés. Leurs écorces sont approvisionnées sur le marché et vendues en majorité par les hommes. G. lucida et S. zenkeri sont utilisées à des fins nutritionnelles, médicinales et lucratives, tandis qu’Alstonia boonei est utilisée exclusivement à des fins médicinales. Pour des personnes plus jeunes, d’une tranche d’âge comprise entre 15 et 35 ans, l’exploitation de l’écorce de ces trois espèces n’a aucun impact néfaste sur la disponibilité des ressources forestières. S’agissant des personnes âgées de 35 à 65 ans, l’exploitation non contrôlée et l’écorçage anarchique de G. lucida et de S. zenkeri peuvent entrainer leur pénurie et même leur disparition dans cette région. Toutefois, la récolte échelonnée de l’écorce de G. lucida, S. zenkeri et A. boonei est utilisée comme stratégie de gestion de l’écorce de ces arbres dans cette localité.   Central African forests are teemed with several goods of animal and plant origin. Goods of plant origin are forest products and non-timber forest products. This research work focused on the identification and importance of some non-timber forest products (NTFPs), especially the bark of tree species (Garcinia lucida, Scorodophloeus zenkeri and Alstonia boonei) in the locality of Ngovayang I. Using a semi-structured questionnaire, the characteristics of the NTFP sector, management strategies, and the impact of NTFP exploitation were determined in Ngovayang I. Surveys show that the bark of these three species is well known and used for various purposes such as consumption, self-medication and sale. The initiation of the use of the bark of these species is linked to sex and also depends on the age of the respondents. Their bark is supplied on the market and sold mostly by men. G. lucida and S. zenkeri are used for food, medicinal and profit-making purposes, while A. boonei is used exclusively for medicinal purposes. For younger people, aged between 15 and 35 years old, the exploitation of the bark of these three species has no negative impact on forest resources. For old people (35 to 65 years), the uncontrolled exploitation and uncontrolled debarking of G. lucida and S. zenkeri can lead to the shortage and even extinction of these two tree species in the region. However, the planned harvest of the bark of Garcinia lucida, Scorodophloeus zenkeri and Alstonia boonei is used as strategy of management of the bark of these trees in this locality.


2010 ◽  
Vol 135 (6) ◽  
pp. 506-510 ◽  
Author(s):  
Jinmin Fu ◽  
Bingru Huang ◽  
Jack Fry

Effects of deficit irrigation applied to home lawns, used as means of water conservation, are an important issue. However, the impact of deficit irrigation on sucrose metabolism in tall fescue (Festuca arundinacea) is unknown and important because sucrose is the dominant form of carbohydrate transported to developing plant organs. The objectives of this study were to investigate the effects of deficit irrigation on leaf water content, osmotic potential (ψS), sucrose level, and the activity of sucrose phosphate synthase (SPS; EC 2.4.1.14), sucrose synthase (SS; EC 2.4.1.13), and acid invertase (AI; EC 3.2.1.26) in tall fescue leaves. Sods of ‘Falcon II’ tall fescue were established in polyvinylchloride (PVC) tubes (10 cm diameter × 40 cm long) filled with a mixture of sand and fritted clay [9:1 (v:v)] and then placed in growth chambers. Reference evapotranspiration rate [ETo (millimeters of water per day)] was determined by weighing the PVC tubes containing well-watered turfgrass every 3 days to determine water loss on a daily basis as ETo. Deficit irrigation treatments were applied as follows: well-watered control, mild drought stress (60% ETo), and severe drought stress (20% ETo). Leaf water content was lower at 6, 12, and 20 days of treatment for the 20% ETo treatment and 20 days after treatment began for the 60% ETo treatment. Compared with the well-watered control, ψS was lower in the 60% ETo treatment on all three measurement dates. Sucrose was higher at 8 and 14 days after treatment began in the 60% ETo treatment and on all three measurement dates in the 20% ETo treatment relative to the well-watered control. No difference in sucrose level was observed between the 20% ETo and 60% ETo irrigation regimes at 8 and 14 days of treatment. Beginning 14 days after treatment, tall fescue had a higher level of SPS in the 60% ETo and 20% ETo treatments compared with the well-watered treatment. Tall fescue receiving 60% or 20% ETo had a lower level of AI activity on all measurement dates. Results suggest that the decrease in ψS was accompanied by higher sucrose levels, which were the result of the increased level of SPS and SS activity and a decline in AI activity.


2019 ◽  
Vol 11 (6) ◽  
pp. 1705 ◽  
Author(s):  
Suizi Wang ◽  
Jiangwen Fan ◽  
Yuzhe Li ◽  
Lin Huang

Livestock grazing is an important determinant of species diversity and plant growth. Overgrazing is identified as one of the most important disturbances resulting in grassland degradation. Although many restoration practices have been implemented, grazing exclusion is one of the most effective methods to restore degraded grasslands. We explored the impact of five years of grazing exclusion on plant growth and species diversity in four types of grasslands: temperate steppe (TS), swamp meadow (SM), alpine steppe (AS), and alpine meadow (AM). Our results showed that grazing exclusion increased plant height, coverage, biomass, and species diversity in all four grasslands. The aboveground biomass in AM (180.8%), TS (117.3%), and SW (105.9%) increased significantly more than AS (10.1%). Grazing exclusion in AM had the greatest effect on proportion of palatable species, and the increase in palatable species in AM was higher than that of the other grassland types significantly. Species diversity increased significantly within the enclosure in SM (23.9%) and AM (20.8%). Our results indicate that grazing exclusion is an effective management strategy to restore degraded grasslands and it works best in alpine meadow. This study contributes to the growing theoretical basis for grassland management strategies and has a significant effect on sustainable development for grassland resources and pastoral areas.


2017 ◽  
Vol 13 (6) ◽  
pp. 116
Author(s):  
Mohammad H. Brake ◽  
Hassan R. Hamasha ◽  
Hussein M. Migdadi ◽  
Ashraf O. Khashroum ◽  
Moath Al-Gharaibeh ◽  
...  

In arid and semi-arid countries such as Jordan, shortage in water sources might affect agricultural development and reduces the effectiveness of economic benefits of most crops planted in such areas. Tomato is an important agricultural crop and faces severe drought stress due to climate changes, therefore, measurement of proline accumulation in plant tissues is used as an indicator for drought stress tolerance. This research was conducted at Jarash University Campus in northern Jordan. A field experiment was carried out to investigate the impact of different storage temperature (+4ºC, - 20ºC and -80ºC) and different storage durations (0, 3, 6 and 11 weeks) on proline content in five different Jordanian tomato landraces. Results indicated that the average free proline content for samples tested directly after leaves collection was 7.1 µmol/g. Proline content in leaves stored at +4 ºC for 3, 6, and 11 weeks was 4.8, 1.8, and 1.1µmol/g, respectively, while for -20ºC was 11.8, 7.9, and 9.5 µmol/g for samples stored for 3, 6, 11 weeks respectively. In contrast the highest values for these parameters were obtained from samples stored at -80ºC, the average measured values of free proline content were 9.5, 7.8, and 12.9 µmol/g at 3, 6, and 11 weeks of storage, respectively. Based on the results obtained by this research, it is recommended to measure proline content directly after leaves collection. However, for large number of samples, keeping the samples at -20ºC not longer than six weeks could be a solution. Finally, we highly recommend the development of in-field method for measurement of free proline content.


2015 ◽  
Author(s):  
◽  
Jeffrey Eric Schneiderman

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Climate change may result in a change in the tree species present within forests. The Missouri Central Hardwood Region represents one area where these changes may occur. Due to the natural diversity of species and economic value of this area, it is beneficial to understand how climate change might affect trees currently present. Computer models (a human creation to help understand real world systems in a simplified manner) can be used to study the impact of climate change on forests. My objectives were to 1) understand how different forest impact models studying climate change compared to each other, 2) determine whether climate change or current timber harvest practices was more likely to change the characteristics of the forest, and 3) analyze land management alternatives to determine which was best at creating beneficial qualities for forests under climate change. For my first objective, I used a species distribution model and a process model, two models that use different analysis approaches, to assess climate change impacts on tree species, and compared the results. On a broad level, both models agreed, but when looking at the study area at smaller resolution, the models did not agree as well. For my second objective, I coupled a process model and forest landscape model. Although results showed there was variation based on species regarding whether climate or harvest had the greater impact, both usually had significant impacts on tree species. Results for my third objective indicated that multiple management approaches are necessary to manage future forests in a beneficial manner. My results have implications for future forest sustainability. Uncertainty exists regarding climate change's full impact, but with proper forest management and research these challenges can be reduced.


Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1507
Author(s):  
Gabriel Duduman ◽  
Ionuț Barnoaiea ◽  
Daniel Avăcăriței ◽  
Cătălina-Oana Barbu ◽  
Vasile-Cosmin Coșofreț ◽  
...  

The study zone includes one of the largest montane old-growth forests in Europe (Slatioara UNESCO site), and understanding the structure and functioning of sill intact forests in Europe is essential for grounding management strategies for secondary forests. For this reason, we set out to analyze the dependencies between aboveground biomass (AgB), tree species and size diversity and terrain morphology, as well as the relationship between biomass and diversity, since neither of these issues have been sufficiently explored. We found that tree species diversity decreases with increased solar radiation and elevation. Tree size heterogeneity reaches its highest mean values at elevations between 1001 and 1100 m, on slopes between 50 and 60 degrees. AgB is differentiated with elevation; the highest mean AgB (293 tonnes per hectare) is recorded at elevations between 801 and 900 m, while it decreases to 79 tonnes per hectare at more than 1500 m a.s.l. It is also influenced by tree species diversity and tree size heterogeneity, with the highest AgB reached in the most complex forest ecosystems in terms of structural diversity. We showed that intact temperate montane forests develop maximum biomass for optimum species diversity and highest size heterogeneity; all three are modulated mainly by elevation.


2020 ◽  
Author(s):  
Julius Sebald ◽  
Timothy Thrippleton ◽  
Werner Rammer ◽  
Harald Bugmann ◽  
Rupert Seidl

&lt;div&gt; &lt;div&gt; &lt;div&gt; &lt;p&gt;Forests are strongly affected by climatic changes, but impacts vary between tree species and prevailing site conditions. A number of studies suggest that increasing tree species diversity is a potent management strategy to decrease climate change impacts in general, and increase the resilience of forest ecosystems to changing disturbance regimes. However, most studies to date have focused on stand-level diversity in tree species (alpha diversity), which is often difficult to implement in operational forest management. Inter-species competition requires frequent management interventions to maintain species mixture and complicates the production of high-quality stemwood. An alternative option to increasing alpha diversity is to increase tree species diversity between forest stands (beta diversity). Here we quantify the effects of alpha and beta diversity on the impact of forest disturbances under climate change. We conducted a simulation experiment applying two forest landscape models (i.e. iLand and LandClim) in two landscapes with strongly contrasting environmental conditions in Central Europe. Simulations investigate different levels of tree species diversity (no diversity, low diversity and high diversity) in different spatial arrangements (alpha diversity, beta diversity). Subsequently a standard forest management regime and a series of prescribed disturbances are applied over 200 years. By analyzing biomass values relative to a no-disturbance run, variation in biomass over time and the number of trees &gt; 30 cm dbh per hectare, we isolate the effect of tree species diversity on the resistance of forests to disturbances.&lt;/p&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt;


2013 ◽  
Vol 61 (2) ◽  
pp. 91-100 ◽  
Author(s):  
S. Bencze ◽  
K. Balla ◽  
T. Janda ◽  
O. Veisz

Phytotron experiments were conducted to examine the impact of elevated atmospheric CO2 level (750 μmol mol−1) on the drought tolerance of winter barley (Petra), durum wheat (Mv Makaroni) and spring oat (Mv Pehely) varieties. Under drought stress conditions, the durum wheat variety was found to be unaffected by CO2 enrichment, as neither the biomass or grain yield nor the antioxidant enzyme activities changed compared to those at ambient CO2. Despite the fact that the spring oat variety had similar grain yield loss due to drought at both CO2 levels, it exhibited reduced antioxidant enzyme activities under less severe drought, indicating a slightly increased tolerance to drought. Winter barley, which exhibited an extremely positive reaction to CO2 enrichment at the control water supply level, also showed increased drought tolerance in response to high CO2. It had low glutathione reductase, glutathione-S-transferase and ascorbate peroxidase activities even at the most severe drought stress levels, while it could also fully compensate for the negative effects of drought on biomass and grain yield parameters when grown at elevated CO2.


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