scholarly journals Tree growth dynamics and ecological recovery in Kitulangalo miombo woodlands Morogoro, Tanzania

2021 ◽  
Vol 2021 (313) ◽  
Author(s):  
Elifuraha Njoghomi
Keyword(s):  
Tree Growth ◽  
Growth Dynamics ◽  
Miombo Woodlands ◽  
Ecological Recovery

scholarly journals Modelling tree growth to determine the sustainability of current off-take from miombo woodland: a case study from rural villages in Malawi

2016 ◽  
Vol 44 (1) ◽  
pp. 66-73 ◽  
Author(s):  
EMMA L. GREEN ◽  
FELIX EIGENBROD ◽  
KATE SCHRECKENBERG ◽  
SIMON WILLCOCK
Keyword(s):  
Ecosystem Services ◽  
Confidence Interval ◽  
Tree Growth ◽  
Growth Rates ◽  
Vegetation Dynamics ◽  
Management Practices ◽  
Sustainable Forest Management ◽  
Miombo Woodlands ◽  
Yield Model ◽  
The Impact

SUMMARYMiombo woodlands supply ecosystem services to support livelihoods in southern Africa, however, rapid deforestation has necessitated greater knowledge of tree growth and off-take rates to understand the sustainability of miombo exploitation. We established 48 tree inventory plots within four villages in southern Malawi, interviewed representatives in these same villages about tree management practices and investigated the impact of climate on vegetation dynamics in the region using the ecosystem modelling framework LPJ-GUESS. Combining our data with the forest yield model MYRLIN revealed considerable variation in growth rates across different land uses; forested lands showed the highest growth rates (1639 [95% confidence interval 1594–1684] kg ha–1 year–1), followed by settlement areas (1453 [95% confidence interval 1376–1530] kg ha–1 year–1). Based on the modelled MYRLIN results, we found that 50% of the villages had insufficient growth rates to meet estimated off-take. Furthermore, the results from LPJ-GUESS indicated that sustainable off-take approaches zero in drought years. Local people have recognized the unsustainable use of natural resources and have begun planting activities in order to ensure that ecosystem services derived from miombo woodlands are available for future generations. Future models should incorporate the impacts of human disturbance and climatic variation on vegetation dynamics; such models should be used to support the development and implementation of sustainable forest management.

scholarly journals Assessing the Performance of the WOFOST Model in Simulating Jujube Fruit Tree Growth under Different Irrigation Regimes

2019 ◽  
Vol 11 (5) ◽  
pp. 1466 ◽  
Author(s):  
Tiecheng Bai ◽  
Nannan Zhang ◽  
Youqi Chen ◽  
Benoit Mercatoris
Keyword(s):  
Tree Growth ◽  
Irrigation Treatment ◽  
Growth Dynamics ◽  
Cropping System ◽  
Fruit Tree ◽  
Total Biomass ◽  
Full Irrigation ◽  
Area Index ◽  
Jujube Fruit ◽  
Irrigation Treatments

Cropping system models are widely employed to evaluate plant water requirements and growth situations. However, these models rarely focus on growth studies of perennial fruit trees. The aim of this study was to evaluate the performance of the WOFOST (WOrld FOod STudies) model in simulating jujube fruit tree growth under different irrigation treatments. The model was calibrated on data obtained from full irrigation treatments in 2016 and 2017. The model was validated on four deficit percentages (60%, 70%, 80%, and 90%) and one full irrigation treatment from 2016 to 2018. Calibrated R2 and RMSE values of simulated versus measured soil moisture content, excluding samples on the day of irrigation and first day after irrigation, reached 0.94 and 0.005 cm3 cm−3. The model reproduced growth dynamics of the total biomass and leaf area index, with a validated R2 = 0.967 and RMSE = 0.915 t ha−1, and R2 = 0.962 and RMSE = 0.160 m2 m−2, respectively. The model also showed good global performance, with R2 = 0.86 and RMSE = 0.51 t ha−1, as well as good local agreement (R2   ≥   0.8 ) and prediction accuracy (RMSE ≤   0.62 t ha−1) for each growth season. Furthermore, 90% of full irrigation can be recommended to achieve a balance between jujube yields and water savings (average decline ratio of yield ≤ 3.8%).

Tree growth dynamics during early ontogenetic stages in closed forests

Trees ◽  
2018 ◽  
Vol 32 (3) ◽  
pp. 671-673 ◽  
Author(s):  
Gianluca Piovesan ◽  
Ulrich Lüttge
Keyword(s):  
Tree Growth ◽  
Growth Dynamics ◽  
Ontogenetic Stages

scholarly journals Intra-Annual Radial Growth of Pinus kesiya var. langbianensis Is Mainly Controlled by Moisture Availability in the Ailao Mountains, Southwestern China

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 899 ◽  
Author(s):  
Fan ◽  
Bräuning ◽  
Fu ◽  
Yang ◽  
Qi ◽  
...  
Keyword(s):  
Tree Growth ◽  
Radial Growth ◽  
Southwest China ◽  
Growth Dynamics ◽  
Limiting Factors ◽  
Local Climate ◽  
Climate Conditions ◽  
Growing Season Length ◽  
Pinus Kesiya ◽  
Moisture Availability

Intra-annual monitoring of tree growth dynamics is increasingly applied to disentangle growth-change relationships with local climate conditions. However, such studies are still very limited in subtropical regions which show a wide variety of climate regimes. We monitored stem radius variations (SRV) of Pinus kesiya var. langbianensis (Szemao pine) over five years (2012–2015 and 2017) in the subtropical monsoon mountain climate of the Ailao Mountains, Yunnan Province, southwest China. On average, the stem radial growth of Szemao pine started in early March and ended in early October, and the highest growth rates occurred during May to June. Stem radius increments were synchronous with precipitation events, while tree water deficit corresponded to the drought periods. Correlation analysis and linear mixed-effects models revealed that precipitation and relative humidity are the most important limiting factors of stem radial increments, whereas air temperature and vapor pressure deficit significantly affected tree water balance and may play an important role in determining the growing season length and seasonality (i.e., duration, start, and cessation). This study reveals that moisture availability plays a major role for tree growth of P. kesiya var langbianensis in the Ailao Mountains, southwest China.

scholarly journals Influence of thinning intensity and canopy type on Scots pine stand and growth dynamics in a mixed managed forest

2016 ◽  
Vol 25 (2) ◽  
pp. e057 ◽  
Author(s):  
Irantzu Primicia ◽  
Rubén Artázcoz ◽  
Juan-Bosco Imbert ◽  
Fernando Puertas ◽  
María-del-Carmen Traver ◽  
...  
Keyword(s):  
Scots Pine ◽  
Tree Growth ◽  
Growth Rates ◽  
Stand Structure ◽  
Growth Dynamics ◽  
Basal Area ◽  
Beech Forest ◽  
Annual Increment ◽  
Thinning Intensity ◽  
Canopy Type

Aim of the study: We analysed the effects of thinning intensity and canopy type on Scots pine growth and stand dynamics in a mixed Scots pine-beech forest. Area of the study: Western Pyrenees. Material and methods: Three thinning intensities were applied in 1999 (0, 20 and 30% basal area removed) and 2009 (0, 20 and 40%) on 9 plots. Within each plot, pure pine and mixed pine-beech patches are distinguished. All pine trees were inventoried in 1999, 2009 and 2014. The effects of treatments on the tree and stand structure variables (density, basal area, stand and tree volume), on the periodic annual increment in basal area and stand and tree volume, and on mortality rates, were analysed using linear mixed effects models. Main Results: The enhancement of tree growth was mainly noticeable after the second thinning. Growth rates following thinning were similar or higher in the moderate than in the severe thinning. Periodic stand volume annual increments were higher in the thinned than in the unthinned plots, but no differences were observed between the thinned treatments. We observed an increase in the differences of the Tree volume annual increment between canopy types (mixed < pure) over time in the unthinned plots, as beech crowns developed. Research highlights: Moderate thinning is suggested as an appropriate forest practice at early pine age in these mixed forests, since it produced higher tree growth rates than the severe thinning and it counteracted the negative effect of beech on pine growth observed in the unthinned plots.Keywords: competition; Fagus sylvatica L.; Pinus sylvestris L.; forest management; mortality; Mediterranean forest.

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