scholarly journals Biomass Yield and Economic, Energy and Carbon Balances of Ulmus pumila L., Robinia pseudoacacia L. and Populus × euroamericana (Dode) Guinier Short-Rotation Coppices on Degraded Lands under Mediterranean Climate

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1337
Author(s):  
Silvia Patricia Alesso ◽  
Raúl Tapias ◽  
Joaquín Alaejos ◽  
Manuel Fernández
Keyword(s):  
Mediterranean Climate ◽  
Renewable Energy Sources ◽  
Robinia Pseudoacacia ◽  
Hybrid Poplar ◽  
Added Value ◽  
Deciduous Tree ◽  
Ulmus Pumila ◽  
High Quality ◽  
Short Rotation ◽  
Robinia Pseudoacacia L

The steadily increasing demand for energy and concerns about climate change have prompted countries to promote the use of renewable energy sources, including lignocellulosic biomass. In this context, this work aims to assess the biomass production for energy purposes in crops with short rotation, as well as its effect on soil properties. Deciduous tree species were used, mainly Siberian elm (Ulmus pumila L.), black locust (Robinia pseudoacacia L.) and a hybrid poplar clone (Populus × euroamericana (Dode) Guinier, clone ‘AF2′). Four field trials were implemented, under two different types of Mediterranean climate, where highly productive taxa were tested, in addition to the mixed planting of a nitrogen-fixing species with a non-fixing one. Short-rotation coppices (SRCs) of these taxa yield about 12–14 t ha−1 year−1 of high-quality dry woody biomass, when fertilizers and irrigation water are supplied; generate 205–237 GJ ha−1 year−1 net and earnings of about EUR 1.5 per EUR 1 invested; and sequester into the soil 0.36–0.83 t ha−1 year−1 of C and 57 kg ha−1 year−1 of N. Therefore, these species raised as SRCs could improve degraded soils if the crop is properly managed, resulting in favorable economic, energy and CO2 emission balances. The use of mixed plantations can bring economic and environmental gains, and the biomass transformation into high-quality chips or pellets gives it added value.

scholarly journals Nutrient Contribution of Litterfall in a Short Rotation Plantation of Pure or Mixed Plots of Populus alba L. and Robinia pseudoacacia L.

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1133 ◽  
Author(s):  
Isabel González ◽  
Hortensia Sixto ◽  
Roque Rodríguez-Soalleiro ◽  
Nerea Oliveira
Keyword(s):  
Leaf Litter ◽  
Robinia Pseudoacacia ◽  
Potential Contribution ◽  
Populus Alba ◽  
Leaf Fall ◽  
Mineral Fertilization ◽  
Potential Reduction ◽  
Short Rotation ◽  
Robinia Pseudoacacia L ◽  
Carbon Contribution

This study aims to quantify the potential contribution of nutrients derived from leaf litter in a short rotation coppice plantation which includes monocultures of the species Populus alba (PA) and Robina pseudoacacia (RP) as well as a mixture of 50PA:50RP, in the middle of the rotation. The P. alba monoculture was that which provided the most leaf litter (3.37 mg ha−1 yr−1), followed by the 50PA:50RP mixture (2.82 mg ha−1 yr−1) and finally the R. pseudoacacia monoculture (2.55 mg ha−1 yr−1). In addition to producing more litterfall, leaves were shed later in the P. alba monoculture later (December) than in the R. pseudoacacia monoculture (October) or the mix (throughout the fall). In terms of macronutrient supply per hectare, the contributions derived from leaf litter were higher for K, P and Mg in the case of P. alba and for N in R. pseudoacacia, the mix presenting the highest Ca content and intermediate concentrations for the rest of the nutrients. In addition, other factors such as C:N or N:MO ratios, as well as the specific characteristics of the soil, can have an important impact on the final contribution of these inputs. The carbon contribution derived from leaf fall was higher in the P. alba monoculture (1.5 mg ha−1 yr−1), intermediate in the mixed plot (1.3 mg ha−1 yr−1) and slightly lower for the R. pseudoacacia monoculture (1.3 mg ha−1 yr−1). Given these different strategies of monocultures with regard to the dynamism of the main nutrients, species mixing would appear to be suitable option to achieve a potential reduction in mineral fertilization in these plantations.

scholarly journals Robinia pseudoacacia L. in Short Rotation Coppice: Seed and Stump Shoot Reproduction as well as UAS-based Spreading Analysis

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 235 ◽  
Author(s):  
Christin Carl ◽  
Jan Lehmann ◽  
Dirk Landgraf ◽  
Hans Pretzsch
Keyword(s):  
Image Analysis ◽  
Seed Germination ◽  
Black Locust ◽  
Robinia Pseudoacacia ◽  
Light Availability ◽  
Short Rotation ◽  
Object Based ◽  
Reproduction Strategies ◽  
Root Suckering ◽  
Robinia Pseudoacacia L

Varying reproduction strategies are an important trait that tree species need in order both to survive and to spread. Black locust is able to reproduce via seeds, stump shoots, and root suckers. However, little research has been conducted on the reproduction and spreading of black locust in short rotation coppices. This research study focused on seed germination, stump shoot resprout, and spreading by root suckering of black locust in ten short rotation coppices in Germany. Seed experiments and sample plots were analyzed for the study. Spreading was detected and measured with unmanned aerial system (UAS)-based images and classification technology—object-based image analysis (OBIA). Additionally, the classification of single UAS images was tested by applying a convolutional neural network (CNN), a deep learning model. The analyses showed that seed germination increases with increasing warm-cold variety and scarification. Moreover, it was found that the number of shoots per stump decreases as shoot age increases. Furthermore, spreading increases with greater light availability and decreasing tillage. The OBIA and CNN image analysis technologies achieved 97% and 99.5% accuracy for black locust classification in UAS images. All in all, the three reproduction strategies of black locust in short rotation coppices differ with regards to initialization, intensity, and growth performance, but all play a role in the survival and spreading of black locust.

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