Individual tree basal area increment models for broadleaved forests in Bhutan DOI Open Access
Jigme Tenzin, Karma Tenzin, Hubert Hasenauer

et al.

Forestry An International Journal of Forest Research, Journal Year: 2016, Volume and Issue: unknown

Published: Dec. 22, 2016

The correct and accurate assessments of growing stock (stem volume) in combination with forest growth predictions from models are essential for sustainable management. Currently, no such information exists the broadleaved forests Bhutan. This study evaluates important factors individual tree species Dagana, Data were collected 96 inventory plots covering stand information, parameters along 5-year increment cores. Due to large number (87), four groups created using principal component cluster analysis simplify calibration basal area (BAI) models. main determinants shown be size variables competition within a stand. Distance dependent indices showed higher correlation than distance independent indices. resulting provided consistent unbiased estimates BAI predictions. Increasing levels reduce productivity trees. emphasises need crown release obtain growth. We demonstrate that developed this can used predict by group according different density conditions and, if they verified on wider scale, could form basis management

Language: Английский

European forests under global climate change: Review of tree growth processes, crises and management strategies DOI
Zdeněk Vacek, Stanislav Vacek, Jan Cukor

et al.

Journal of Environmental Management, Journal Year: 2023, Volume and Issue: 332, P. 117353 - 117353

Published: Jan. 28, 2023

Language: Английский

Citations

99
A generalized nonlinear mixed-effects height to crown base model for Mongolian oak in northeast China DOI
Liyong Fu, Huiru Zhang, Ram P. Sharma

et al.

Forest Ecology and Management, Journal Year: 2016, Volume and Issue: 384, P. 34 - 43

Published: Oct. 25, 2016

Language: Английский

Citations

77
Modelling crown width–diameter relationship for Scots pine in the central Europe DOI
Ram P. Sharma, Lukáš Bílek, Zdeněk Vacek

et al.

Trees, Journal Year: 2017, Volume and Issue: 31(6), P. 1875 - 1889

Published: Aug. 10, 2017

Language: Английский

Citations

65
Mixed vs. monospecific mountain forests in response to climate change: structural and growth perspectives of Norway spruce and European beech DOI
Zdeněk Vacek,

Anna Prokůpková,

Stanislav Vacek

et al.

Forest Ecology and Management, Journal Year: 2021, Volume and Issue: 488, P. 119019 - 119019

Published: Feb. 26, 2021

Language: Английский

Citations

53
A bottom-up quantification of foliar mercury uptake fluxes across Europe DOI Creative Commons
Lena Wohlgemuth, Stefan Osterwalder,

Carl Joseph

et al.

Biogeosciences, Journal Year: 2020, Volume and Issue: 17(24), P. 6441 - 6456

Published: Dec. 21, 2020

Abstract. The exchange of gaseous elemental mercury, Hg(0), between the atmosphere and terrestrial surfaces remains poorly understood mainly due to difficulties in measuring net Hg(0) fluxes on ecosystem scale. Emerging evidence suggests foliar uptake atmospheric be a major deposition pathway surfaces. Here, we present bottom-up approach calculate aboveground foliage by combining Hg rates normalized leaf area with species-specific indices. This incorporates systematic variations crown height needle age. We analyzed content 583 samples from six tree species at 10 European forested research sites along latitudinal gradient Switzerland northern Finland over course 2018 growing season. Foliar concentrations increased time all sites. found that were highest top crown. decreased age multiyear-old conifers (spruce pine). Average during season 18 ± 3 µg m−2 for beech, 26 5 oak, 4 1 pine 11 spruce. For comparison, average Hg(II) wet flux measured same period was 2.3 0.3 m−2, which times lower than site-averaged m−2. Scaling up site-specific Europe resulted total approximately 20 Mg Considering applies global land temperate forests, estimate 108 Mg. Our data indicate is Europe. provides promising method quantify an

Language: Английский

Citations

50
Developing crown width model for mixed forests using soil, climate and stand factors DOI
Dongyuan Tian, Pei He,

Lichun Jiang

et al.

Journal of Ecology, Journal Year: 2024, Volume and Issue: 112(2), P. 427 - 442

Published: Jan. 3, 2024

Abstract The tree crown is a useful measure of vigour and highly relevant to tree's environmental adaptability. Crown allometry depends on stand conditions. Several studies have focussed the effects climate change competitive intensity crown, but regulatory role soil resources diversity carbon allocation has been neglected. Data from 20,994 trees in 232 mixed forests collected between 2011 2019 were located near four major mountain ranges northeast China. proposed width model includes developmental stage, soil, climate, competition intensity, species mixture, diversity, structural their interactions. We observed that cross‐species allometric scaling exponent does not conform universal law. Our results showed increased with increasing bulk density, quadratic mean diameter coefficient variation decreased de Martonne aridity index, basal area, Simpson index mixture. interaction density had significant negative effect width. influence particular factor within term was modulated by gradients other factors. Furthermore, contributed more modelling than greater diversity. Synthesis . provide new insights into variability under global change, which critical for improving regional estimates forest biomass stocks.

Language: Английский

Citations

7
A generalized interregional nonlinear mixed-effects crown width model for Prince Rupprecht larch in northern China DOI
Liyong Fu, Ram P. Sharma,

Kaijie Hao

et al.

Forest Ecology and Management, Journal Year: 2017, Volume and Issue: 389, P. 364 - 373

Published: Jan. 17, 2017

Language: Английский

Citations

60
Modelling individual tree height–diameter relationships for multi-layered and multi-species forests in central Europe DOI
Ram P. Sharma, Zdeněk Vacek, Stanislav Vacek

et al.

Trees, Journal Year: 2018, Volume and Issue: 33(1), P. 103 - 119

Published: Sept. 19, 2018

Language: Английский

Citations

56
Prediction of tree crown width in natural mixed forests using deep learning algorithm DOI Creative Commons
Yangping Qin,

Biyun Wu,

Xiangdong Lei

et al.

Forest Ecosystems, Journal Year: 2023, Volume and Issue: 10, P. 100109 - 100109

Published: Jan. 1, 2023

Crown width (CW) is one of the most important tree metrics, but obtaining CW data laborious and time-consuming, particularly in natural forests. The Deep Learning (DL) algorithm has been proposed as an alternative to traditional regression, its performance predicting mixed forests unclear. aims this study were develop DL models for spruce-fir-broadleaf north-eastern China, analyse contribution size, species, site quality, stand structure, competition prediction, compare with nonlinear effects (NLME) their reliability. An amount total 10,086 individual trees 192 subplots employed study. results indicated that all deep neural network (DNN) free overfitting statistically stable within 10-fold cross-validation, best DNN model could explain 69% variation no significant heteroskedasticity. In addition diameter at breast height, showed on CW. NLME (R2 ​= ​0.63) outperformed ​0.54) when six input variables consistent, opposite ​0.69) included 22 variables. These demonstrated great potential prediction.

Language: Английский

Citations

16
Effects of tree vigor, competition and stand conditions on branch diameter for mixed plantations of Fraxinus mandshurica Rupr. and Larix olgensis Henry in Northeast China DOI
Xinyang Zou, Zheng Miao, Yuanshuo Hao

et al.

European Journal of Forest Research, Journal Year: 2024, Volume and Issue: 143(4), P. 1165 - 1180

Published: April 2, 2024

Language: Английский

Citations

5