The belowground biomass is represented by coarse and fine roots. Concentrated in the superficial horizons of the soil, the fine roots play a crucial role in the functioning of a forest ecosystem. However, studies on t...The belowground biomass is represented by coarse and fine roots. Concentrated in the superficial horizons of the soil, the fine roots play a crucial role in the functioning of a forest ecosystem. However, studies on their dynamics in natural forests are almost non-existent in the Republic of Congo. Here, we estimated the biomass, production, turnover and fine root lifespan of two forest strata of a semi-deciduous forest: the <i><span style="font-family:Verdana;">Gilbertiodendron dewevrei</span></i><span style="font-family:Verdana;"> (De Wild.) J. Léonard forest (GF) and the mixed forest (MF) of land. The ingrowth cores method was used to estimate the biomass, production, turnover and lifespan of fine roots. The results of this study revealed that the biomass, production and fine root turnover of the two forest strata studied significantly decreased with increasing soil depth, with an increase in lifespan. The annual fine root biomass of GF (2284.50 ± 37.62 <img src="Edit_990c94b6-013e-4e21-90df-d1388dc0e65f.png" alt="" /></span><span style="font-family:Verdana;"> and 1034.61 ± 14.52 <img src="Edit_dff42540-5a2f-413b-8620-cb500e9961e2.png" alt="" /></span><span style="font-family:Verdana;">) was slightly lower than that of MF (2430.07 ± 40.68 <img src="Edit_66800589-8460-4c37-83b2-2df0f335d75d.png" alt="" /></span><span style="font-family:Verdana;"> and 1043.10 ± 11.75 <img src="Edit_c22f255e-d910-4b49-a6a4-033516044362.png" alt="" /></span><span style="font-family:Verdana;">) in the 0-15 cm and 15-30 cm horizons, respectively. The annual production of fine roots from these latter horizons was respectively 1300.19 ± 32.17 <img src="Edit_5482204b-8e9e-476a-907d-0865bf3a1c99.png" alt="" /></span><span style="font-family:Verdana;"> and 539.18 ± 11.55 <img src="Edit_65a2856e-5322-4fc9-b42a-3ba1176fa992.png" alt="" /></span><span style="font-family:Verdana;"> in GF and 1362.24 ± 39.59 <img src="Edit_9802e464-658d-48eb-9b57-8e746c3e8ef4.png" alt="" /></span><span style="font-family:Verdana;"> and 492.95 ± 14.38 <img src="Edit_51413fca-930c-45b9-a385-2b55d4d2bac8.png" alt="" /></span><span style="font-family:Verdana;"> in the MF. Root turnover was higher in the GF (1.68 ± 0.05 <img src="Edit_ce9d780c-6a46-46c4-aad2-653309318e29.png" alt="" /></span><span style="font-family:Verdana;"> and 1.35 ± 0.03 <img src="Edit_d66d8b7b-c608-4398-9441-e85547f03dea.png" alt="" /></span><span style="font-family:Verdana;">) than in the MF (1.57 ± 0.05 <img src="Edit_cb79094f-88a0-401c-a3e7-06eedb2cef9a.png" alt="" /></span><span style="font-family:Verdana;"> and 1.13 ± 0.02 <img src="Edit_e4f9b6d7-2e2e-44d5-8662-862b8f8ff80e.png" alt="" /></span><span style="font-family:Verdana;">). The lifespan of fine roots increased with the depth of the soil. The difference in fine root dynamics observed between the forest strata studied was influenced by the Evenness index and the above-ground biomass.</span>展开更多
Although numerous studies have proposed explanations for the specific and relative effects of stand structure,plant diversity,and environmental conditions on carbon(C)storage in forest ecosystems,understanding how the...Although numerous studies have proposed explanations for the specific and relative effects of stand structure,plant diversity,and environmental conditions on carbon(C)storage in forest ecosystems,understanding how these factors collectively affect C storage in different community layers(trees,shrubs,and herbs)and forest types(mixed,broad-leaved(E),broad-leaved(M),and coniferous forest)continues to pose challenges.To address this,we used structural equation models to quantify the influence of biotic factors(mean DBH,mean height,maximum height,stem density,and basal area)and abiotic factors(elevation and canopy openness),as well as metrics of species diversity(Shannon–Wiener index,Simpson index,and Pielou’s evenness)in various forest types.Our analysis revealed the critical roles of forest types and elevation in explaining a substantial portion of variability in C storage in the overstory layer,with a moderate influence of stand factors(mean DBH and basal area)and a slightly negative impact of tree species diversity(Shannon–Wiener index).Notably,forest height emerged as the primary predictor of C storage in the herb layer.Regression relationships further highlighted the significant contribution of tree species diversity to mean height,understory C storage,and branch biomass within the forest ecosystem.Our insights into tree species diversity,derived from structural equation modeling of C storage in the overstory,suggest that the effects of tree species diversity may be influenced by stem biomass in statistical reasoning within temperate forests.Further research should also integrate tree species diversity with tree components biomass,forest mean height,understory C,and canopy openness to understand complex relationships and maintain healthy and sustainable ecosystems in the face of global climate challenges.展开更多
Forest structural complexity influences arthropod communities by shaping habitat availability,microclimatic conditions,and resource distribution.However,the extent to which structural complexity and specific structura...Forest structural complexity influences arthropod communities by shaping habitat availability,microclimatic conditions,and resource distribution.However,the extent to which structural complexity and specific structural components drive arthropod abundance and biomass remains poorly understood in temperate forests.This study examined how local and landscape-scale forest characteristics influence arthropod communities across vertical strata(forest floor(FF),herb layer(HL),and shrub layer(SL))in 19 temperate deciduous forests in Belgium,dominated by pedunculate oak,European beech,or Canadian poplar.At the local scale,we assessed dominant tree species identity,overall forest structural complexity,and its components(vertical and horizontal structure,woody layer,herbal layer,and deadwood).At the landscape scale,we evaluated forest area,edge length,forest cover,and vegetation greenness(normalized difference vegetation index(NDVI)).Contrary to expectation,arthropod biomass and abundance did not consistently increase with higher structural complexity.Instead,woody layer complexity,dominant tree species,and NDVI emerged as key drivers,with effects varying by context and stratum.Arthropod abundance and biomass were the highest in oak-and poplar-dominated forests and the lowest in beech forests,likely due to differences in litter quality,microhabitat availability,and understory development.Woody layer complexity positively influenced forest floor arthropods in poplar forests but had a negative effect in oak forests.At the landscape scale,NDVI unexpectedly showed negative relationships with arthropod abundance across strata and with arthropod biomass in the herb layer,likely reflecting dense canopy suppression of understory productivity.Arthropod biomass on the forest floor increased with forest cover,while abundance in the shrub layer decreased with forest cover but increased with forest area.These findings highlight the complex interplay between forest structural attributes,dominant tree species,and landscape factors in shaping arthropod communities.By identifying the key drivers of arthropod abundance and biomass,this study contributes to a better understanding of biodiversity patterns in temperate forests and their ecological dynamics.展开更多
文摘The belowground biomass is represented by coarse and fine roots. Concentrated in the superficial horizons of the soil, the fine roots play a crucial role in the functioning of a forest ecosystem. However, studies on their dynamics in natural forests are almost non-existent in the Republic of Congo. Here, we estimated the biomass, production, turnover and fine root lifespan of two forest strata of a semi-deciduous forest: the <i><span style="font-family:Verdana;">Gilbertiodendron dewevrei</span></i><span style="font-family:Verdana;"> (De Wild.) J. Léonard forest (GF) and the mixed forest (MF) of land. The ingrowth cores method was used to estimate the biomass, production, turnover and lifespan of fine roots. The results of this study revealed that the biomass, production and fine root turnover of the two forest strata studied significantly decreased with increasing soil depth, with an increase in lifespan. The annual fine root biomass of GF (2284.50 ± 37.62 <img src="Edit_990c94b6-013e-4e21-90df-d1388dc0e65f.png" alt="" /></span><span style="font-family:Verdana;"> and 1034.61 ± 14.52 <img src="Edit_dff42540-5a2f-413b-8620-cb500e9961e2.png" alt="" /></span><span style="font-family:Verdana;">) was slightly lower than that of MF (2430.07 ± 40.68 <img src="Edit_66800589-8460-4c37-83b2-2df0f335d75d.png" alt="" /></span><span style="font-family:Verdana;"> and 1043.10 ± 11.75 <img src="Edit_c22f255e-d910-4b49-a6a4-033516044362.png" alt="" /></span><span style="font-family:Verdana;">) in the 0-15 cm and 15-30 cm horizons, respectively. The annual production of fine roots from these latter horizons was respectively 1300.19 ± 32.17 <img src="Edit_5482204b-8e9e-476a-907d-0865bf3a1c99.png" alt="" /></span><span style="font-family:Verdana;"> and 539.18 ± 11.55 <img src="Edit_65a2856e-5322-4fc9-b42a-3ba1176fa992.png" alt="" /></span><span style="font-family:Verdana;"> in GF and 1362.24 ± 39.59 <img src="Edit_9802e464-658d-48eb-9b57-8e746c3e8ef4.png" alt="" /></span><span style="font-family:Verdana;"> and 492.95 ± 14.38 <img src="Edit_51413fca-930c-45b9-a385-2b55d4d2bac8.png" alt="" /></span><span style="font-family:Verdana;"> in the MF. Root turnover was higher in the GF (1.68 ± 0.05 <img src="Edit_ce9d780c-6a46-46c4-aad2-653309318e29.png" alt="" /></span><span style="font-family:Verdana;"> and 1.35 ± 0.03 <img src="Edit_d66d8b7b-c608-4398-9441-e85547f03dea.png" alt="" /></span><span style="font-family:Verdana;">) than in the MF (1.57 ± 0.05 <img src="Edit_cb79094f-88a0-401c-a3e7-06eedb2cef9a.png" alt="" /></span><span style="font-family:Verdana;"> and 1.13 ± 0.02 <img src="Edit_e4f9b6d7-2e2e-44d5-8662-862b8f8ff80e.png" alt="" /></span><span style="font-family:Verdana;">). The lifespan of fine roots increased with the depth of the soil. The difference in fine root dynamics observed between the forest strata studied was influenced by the Evenness index and the above-ground biomass.</span>
基金supported by the Fundamental Research Funds for the Central Universities(2021ZY89)the National Natural Science Foundation of China(32201258 and 32271652)+4 种基金Research Service Project on the Effects of Extreme Climate on Biodiversity and Conservation Strategies in Mentougou District(2024HXFWBH-XJL-02)the Fang Jingyun Ecological Study Studio of Yunnan Province(China)the State Scholarship Fund of China(2011811457)support to the Xingdian Scholar Fund of Yunnan Provincethe Double Top University Fund of Yunnan University.
文摘Although numerous studies have proposed explanations for the specific and relative effects of stand structure,plant diversity,and environmental conditions on carbon(C)storage in forest ecosystems,understanding how these factors collectively affect C storage in different community layers(trees,shrubs,and herbs)and forest types(mixed,broad-leaved(E),broad-leaved(M),and coniferous forest)continues to pose challenges.To address this,we used structural equation models to quantify the influence of biotic factors(mean DBH,mean height,maximum height,stem density,and basal area)and abiotic factors(elevation and canopy openness),as well as metrics of species diversity(Shannon–Wiener index,Simpson index,and Pielou’s evenness)in various forest types.Our analysis revealed the critical roles of forest types and elevation in explaining a substantial portion of variability in C storage in the overstory layer,with a moderate influence of stand factors(mean DBH and basal area)and a slightly negative impact of tree species diversity(Shannon–Wiener index).Notably,forest height emerged as the primary predictor of C storage in the herb layer.Regression relationships further highlighted the significant contribution of tree species diversity to mean height,understory C storage,and branch biomass within the forest ecosystem.Our insights into tree species diversity,derived from structural equation modeling of C storage in the overstory,suggest that the effects of tree species diversity may be influenced by stem biomass in statistical reasoning within temperate forests.Further research should also integrate tree species diversity with tree components biomass,forest mean height,understory C,and canopy openness to understand complex relationships and maintain healthy and sustainable ecosystems in the face of global climate challenges.
基金supported by the UGent GOA project“Forest biodiversity and multifunctionality drive chronic stress-mediated dynamics in pathogen reservoirs(FORESTER)”(No.BOF20/GOA/009).
文摘Forest structural complexity influences arthropod communities by shaping habitat availability,microclimatic conditions,and resource distribution.However,the extent to which structural complexity and specific structural components drive arthropod abundance and biomass remains poorly understood in temperate forests.This study examined how local and landscape-scale forest characteristics influence arthropod communities across vertical strata(forest floor(FF),herb layer(HL),and shrub layer(SL))in 19 temperate deciduous forests in Belgium,dominated by pedunculate oak,European beech,or Canadian poplar.At the local scale,we assessed dominant tree species identity,overall forest structural complexity,and its components(vertical and horizontal structure,woody layer,herbal layer,and deadwood).At the landscape scale,we evaluated forest area,edge length,forest cover,and vegetation greenness(normalized difference vegetation index(NDVI)).Contrary to expectation,arthropod biomass and abundance did not consistently increase with higher structural complexity.Instead,woody layer complexity,dominant tree species,and NDVI emerged as key drivers,with effects varying by context and stratum.Arthropod abundance and biomass were the highest in oak-and poplar-dominated forests and the lowest in beech forests,likely due to differences in litter quality,microhabitat availability,and understory development.Woody layer complexity positively influenced forest floor arthropods in poplar forests but had a negative effect in oak forests.At the landscape scale,NDVI unexpectedly showed negative relationships with arthropod abundance across strata and with arthropod biomass in the herb layer,likely reflecting dense canopy suppression of understory productivity.Arthropod biomass on the forest floor increased with forest cover,while abundance in the shrub layer decreased with forest cover but increased with forest area.These findings highlight the complex interplay between forest structural attributes,dominant tree species,and landscape factors in shaping arthropod communities.By identifying the key drivers of arthropod abundance and biomass,this study contributes to a better understanding of biodiversity patterns in temperate forests and their ecological dynamics.
