Conifer tree plantations for land rehabilitation: an ecological‐functional evaluation

Plantations of exotic fast‐growing tree species have been widely used for maintaining or restoring ecosystem functions. Despite this, in tropical countries with high biodiversity, these plantations have been the subject of heated debate. We evaluated the long‐term effect of coniferous tree plantations (Cupressus lusitanica, Pinus patula, Pinus elliottii) on the ecological rehabilitation of the Andean highlands in Colombia. To determine degree of rehabilitation, we assessed whether there were differences in the structure or density of native understory vegetation or soil ecological properties between plots established within tree plantations and plots established within other vegetation cover types (secondary forests, ferns, pastures, and abandoned mining areas). Measured variables were combined to create an index of ecological rehabilitation (ERI). We found significant differences in the ERI values among vegetation cover types: secondary forest (11.78) > conifer plantations (P. elliottii: 6.23, P. patula: 5.33, C. lusitanica: 5.24) > ferns (4.16) > pasture (2.50) > abandoned mining areas (0.43). The results obtained showed that, from the structure of native understory vegetation and soil ecological properties, conifer plantations favored the rehabilitation process. However, among them, it was highlighted that the P. elliotii plantations showed significant differences in the density of native understory species, their values being 1.7 and 2.1 times higher than those corresponding to P. patula and C. lusitanica, respectively. Thus, unlike these plantations that could represent an ecological barrier over time, P. elliottii plantations have enabled the advancement of natural succession, showing a high diversity of native species.     

Pine invasion decreases density and changes native tree communities in woodland Cerrado

ABSTRACT

Background: Invasive plants can negatively impact native communities, but the majority of the effects of these invasions have been demonstrated only for temperate ecosystems. Tropical ecosystems, including the Cerrado, a biodiversity hotspot, are known to be invaded by numerous non-native species, but studies of their impacts are largely lacking.

Aims: Our research aimed at quantifying how Pinus spp. presence and density affected Cerrado plant communities.

Methods: We sampled areas invaded and non-invaded by Pinus spp. to determine if pine invasion affected native tree richness, diversity, evenness, and density. We also evaluated if community composition differed between invaded and non-invaded sites.

Results: We found invaded plots had lower native tree densities than non-invaded plots and that Pinus spp. invasions changed native tree communities by reducing native species abundances.

Conclusion: Invasive pines had negative impacts on the native Cerrado tree community by reducing native plant density and changing species abundances. Reduced density and abundance at early invasion stages can result in reduction in biodiversity in the long term.     

Co-invading ectomycorrhizal fungal succession in pine-invaded mountain grasslands

Ectomycorrhizal (EM) fungal communities that associate with invading pines (Pinus spp.) are expected to be poor in species diversity. However, long-term successional trajectories and the persistence of dispersal limitations of EM fungi in the exotic range are not well understood. We sampled the roots and surrounding soil of Pinus elliottii and P. taeda trees invading mountain grasslands of Argentina. We also sampled the EM fungal spore bank in grassland soil near (∼150 m) and far (∼850 m) from the original pine plantations. We found 86 different co-invasive EM fungal OTUs. Differential dispersal capacities among EM fungi were detected in the spore bank of grassland soil, but not under mature pines. After thirty years of invasion, the age, but not the degree of spatial isolation of pine individuals affected the EM fungal composition. We showed how EM fungal succession occurs during pine invasions, which may have clear consequences for ecosystem functioning of co-invaded sites.     

Plant richness and composition in hardwood forest understories vary along an acidic deposition and soil-chemical gradient in the northeastern United States

Aims

A century of atmospheric deposition of sulfur and nitrogen has acidified soils and undermined the health and recruitment of foundational tree species in the northeastern US. However, effects of acidic deposition on the forest understory plant communities of this region are poorly documented. We investigated how forest understory plant species composition and richness varied across gradients of acidic deposition and soil acidity in the Adirondack Mountains of New York State.

Methods

We surveyed understory vegetation and soils in hardwood forests on 20 small watersheds and built models of community composition and richness as functions of soil chemistry, nitrogen and sulfur deposition, and other environmental variables.

Results

Community composition varied significantly with gradients of acidic deposition, soil acidity, and base cation availability (63% variance explained). Several species increased with soil acidity while others decreased. Understory plant richness decreased significantly with increasing soil acidity (r?=?0.60). The best multivariate regression model to predict richness (p?<?0.001, adjusted-R²?=?0.60) reflected positive effects of pH and carbon-to-nitrogen ratio (C:N).

Conclusions

The relationship we found between understory plant communities and a soil-chemical gradient, suggests that soil acidification can reduce diversity and alter the composition of these communities in northern hardwood forests exposed to acidic deposition.

     

Effects of experimental nitrogen additions on plant diversity in an old‐growth tropical forest

Response of plant biodiversity to increased availability of nitrogen (N) has been investigated in temperate and boreal forests, which are typically N‐limited, but little is known in tropical forests. We examined the effects of artificial N additions on plant diversity (species richness, density and cover) of the understory layer in an N saturated old‐growth tropical forest in southern China to test the following hypothesis: N additions decrease plant diversity in N saturated tropical forests primarily from N‐mediated changes in soil properties. Experimental additions of N were administered at the following levels from July 2003 to July 2008: no addition (Control); 50 kg N ha^?1 yr^?1 (Low‐N); 100 kg N ha^?1 yr^?1 (Medium‐N), and 150 kg N ha^?1 yr^?1 (High‐N). Results showed that no understory species exhibited positive growth response to any level of N addition during the study period. Although low‐to‐medium levels of N addition (≤100 kg N ha^?1 yr^?1) generally did not alter plant diversity through time, high levels of N addition significantly reduced species diversity. This decrease was most closely related to declines within tree seedling and fern functional groups, as well as to significant increases in soil acidity and Al mobility, and decreases in Ca availability and fine‐root biomass. This mechanism for loss of biodiversity provides sharp contrast to competition‐based mechanisms suggested in studies of understory communities in other forests. Our results suggest that high‐N additions can decrease plant diversity in tropical forests, but that this response may vary with rate of N addition.     

Recovery of vegetation in a Caledonian pinewood after fire

Summary

Following a wildfire in the Caledonian pinewood at Shieldaig, Wester Ross in late March 1974, the recovery of the vegetation, particularly Scots pine (Pinus sylvestris) seedlings, was monitored in twenty sample plots. Almost all trees under 5 cm diameter at breast height were immediately killed by the fire and of the larger trees, 45 per cent of the Scots pine and 60 per cent of the birch (Betula pendula) had died by 1980. Regeneration of Scots pine had occurred to the extent of about 2,500 seedlings ha^-1 by 1980. Recovery of the field layer species varied; species with rhizomes grew up quickly but the re-establishment of cover by Calluna vulgaris and many bryophytes was slow.     

Accompanying vegetation in young <Emphasis Type="Italic">Pinus radiata</Emphasis> plantations enhances recolonization by <Emphasis Type="Italic">Ceroglossus chilensis</Emphasis> (Coleoptera: Carabidae) after clearcutting

The replacement of native forests by Pinus radiata plantations modifies habitat availability and quality for wildlife, constituting a threat to species survival. However, the presence of understory in mature pine plantations minimizes the negative impacts of native forest replacement, rendering a secondary habitat for wildlife. Whether forest-dwelling species recolonize clear-felled areas pending on the spontaneous development of accompanying vegetation growing after harvesting is yet to be assessed. In this context, we analyze the abundance, movement and habitat selection of the endemic ground beetle Ceroglossus chilensis (Coleoptera: Carabidae) in an anthropic forest landscape consisting of native forest remnants, adult pine plantations (>?20 years) with a well-developed understory, and young (1–2 years) pine plantations with varying degrees of accompanying vegetation development. Particularly, we analyze the likelihood that C. chilensis would recolonize young pine plantations depending on the presence (>?70% cover) or the absence (<?20% cover) of this accompanying vegetation. C. chilensis shows a greater probability of selecting habitats with understory (pine plantations and native forest) and young plantations with accompanying vegetation (future understory) than habitats without such vegetation. Movement of C. chilensis also favors their permanence in habitats with understory vegetation, coinciding with higher abundances than in young pine plantations devoid of accompanying vegetation. Hence, the effect of clearcutting could be mitigated by allowing the development of accompanying vegetation into a future understory, which facilitates the recolonization of pine plantations and its use as secondary habitat for wildlife.     

Understory vegetation response to mechanical mastication and other fuels treatments in a ponderosa pine forest

Questions: What influence does mechanical mastication and other fuel treatments have on: (1) canopy and forest floor response variables that influence understory plant development; (2) initial understory vegetation cover, diversity, and composition; and (3) shrub and non‐native species density in a second‐growth ponderosa pine forest. Location: Challenge Experimental Forest, northern Sierra Nevada, California, USA. Methods: We compared the effects of mastication only, mastication with supplemental treatments (tilling and prescribed fire), hand removal, and a control on initial understory vegetation response using a randomized complete block experimental design. Each block (n=4) contained all five treatments and understory vegetation was surveyed within 0.04‐ha plots for each treatment. Results: While mastication alone and hand removal dramatically reduced the midstory vegetation, these treatments had little effect on understory richness compared with control. Prescribed fire after mastication increased native species richness by 150% (+6.0 species m²) compared with control. However, this also increased non‐native species richness (+0.8 species m²) and shrub seedling density (+24.7 stems m²). Mastication followed by tilling resulted in increased non‐native forb density (+0.7 stems m²). Conclusions: Mechanical mastication and hand removal treatments aided in reducing midstory fuels but did not increase understory plant diversity. The subsequent treatment of prescribed burning not only further reduced fire hazard, but also exposed mineral soil, which likely promoted native plant diversity. Some potential drawbacks to this treatment include an increase of non‐native species and stimulation of shrub seed germination, which could alter ecosystem functions and compromise fire hazard reduction in the long‐term.     

Resistance to wildfire and early regeneration in natural broadleaved forest and pine plantation

The response of an ecosystem to disturbance reflects its stability, which is determined by two components: resistance and resilience. We addressed both components in a study of early post-fire response of natural broadleaved forest (Quercus robur, Ilex aquifolium) and pine plantation (Pinus pinaster, Pinus sylvestris) to a wildfire that burned over 6000 ha in NW Portugal. Fire resistance was assessed from fire severity, tree mortality and sapling persistence. Understory fire resistance was similar between forests: fire severity at the surface level was moderate to low, and sapling persistence was low. At the canopy level, fire severity was generally low in broadleaved forest but heterogeneous in pine forest, and mean tree mortality was significantly higher in pine forest. Forest resilience was assessed by the comparison of the understory composition, species diversity and seedling abundance in unburned and burned plots in each forest type. Unburned broadleaved communities were dominated by perennial herbs (e.g., Arrhenatherum elatius) and woody species (e.g., Hedera hibernica, Erica arborea), all able to regenerate vegetatively. Unburned pine communities presented a higher abundance of shrubs, and most dominant species relied on post-fire seeding, with some species also being able to regenerate vegetatively (e.g., Ulex minor, Daboecia cantabrica). There were no differences in diversity measures in broadleaved forest, but burned communities in pine forest shared less species and were less rich and diverse than unburned communities. Seedling abundance was similar in burned and unburned plots in both forests. The slower reestablishment of understory pine communities is probably explained by the slower recovery rate of dominant species. These findings are ecologically relevant: the higher resistance and resilience of native broadleaved forest implies a higher stability in the maintenance of forest processes and the delivery of ecosystem services.     

Properties of Phenylalanyl-tRNA Synthetase and Phenylalanine Ammonia-lyase of Pine Suspension Cultures

Phenylalanyl-tRNA synthetase and phenylalanine ammonia-lyase activities were demonstrated in partially purified extracts of pine (Pinus elliottii) suspension cultures. The optimum pH for the phenylalanyl-tRNA synthetase reaction was 7.5 and the optimum ATP and Mg²⁺ concentrations were 1.0 and 15 mM respectively. Pine, calf liver and yeast tRNA were inadequate substitutes for pea tRNA in the synthetase reaction mixtures. The optimum pH for the phenylalanine ammonia-lyase reaction was 9.0. The K_m for phenylalanine was approximately 6.6 × 10^?5M. The activity of both enzymes in the partially purified extracts was unstable on storage.     

Passive Restoration of Atlantic Forest Following Pinus taeda Harvesting in Southern Brazil

The understory of exotic tree plantations can have non‐negligible native species richness. Ecological restoration of these sites may include the harvest of trees, depending on the tradeoff between timber income and harvest impacts on biodiversity. This study aimed to investigate how a site can recover from harvest disturbance, by comparing the regeneration of woody species in the understory of two types of 37‐year‐old Pinus taeda plantation (P1 and P2, high and low relative density of pine seedlings in the understory, respectively), with stands that were similar to P2 but subjected to harvest and then abandoned for 15 years (R sites). Secondary forests (SF) were used as references. We sampled three different sites for each stand condition; soil chemical properties, estimations of litter mass, and canopy cover were measured. P1 had low species diversity, and P2 and R had 50 and 46% of SF richness, respectively. The R site contained few pine saplings and was floristically similar to P2; this indicated that 15 years was sufficient for the recovery of plant diversity to near pre‐harvesting levels. Soil fertility was highest in SF and lowest in P1. Thus old plantations of P. taeda with low relative density of pine juveniles can be cost‐effective starting points for restoration. Despite the destructive effects of pine harvest, recovery of native species can occur rapidly. In situations in which clearcutting of pine stands is not planned or possible, modest thinning of P. taeda adults and/or intensive thinning of juveniles could expedite restoration.     

南方红壤区3种典型森林恢复方式对植物群落多样性的影响

合理的森林恢复方式能提高植物多样性,进而提高生态系统服务功能.在我国南方红壤区研究了3种典型森林恢复方式(引进种恢复的湿地松(Pinus elliottii)人工林本地种恢复的马尾松(Pinus massoniana)人工林和自然恢复的天然次生林)的植物区系构成和植物群落多样性.结果表明:(1)湿地松人工林有155种植物,隶属66科118属,马尾松人工林有137种植物,隶属59科97属;天然次生林有226种植物,隶属86科160属,3种森林恢复方式的乔木层、灌木层和草本层的优势科属明显不同,马尾松人工林的优势物种和天然次生林更相似;(2)天然次生林的植物区系基本构成、植物区系类型种类高于马尾松人工林和湿地松人工林,并且天然次生林的温带成分比例高于湿地松人工林;(3)恢复方式对植物群落的多样性指数有显著影响,天然次生林的物种丰富度、辛普森指数明显高于马尾松人工林和湿地松人工林,两种人工林之间差异不显著;(4)3种森林恢复方式的植物群落结构存在显著差异,相比湿地松人工林,马尾松人工林的植物群落组成与天然次生林更相似.总之,自然恢复的天然次生林植物群落多样性高于人工恢复的马尾松人工林和湿地松人工林,本地种马尾松人工林在维持区域植物群落结构功能上优于引进种湿地松人工林.     

Asymbiotic nitrogen fixation in the litter and surface soil of a Pinus laricio Poiret forest (Sila,Calabria, Italy)

Abstract

Nitrogen fixation was measured in a Corsican pine (Pinus laricio Poiret) forest in Calabria (Southern Italy). Acetylene reduction activity (ARA) and CO₂ production levels were determined by incubation of litter and superficial (0–5 cm) soil layer samples in the field, at monthly intervals. ARA variations were not correlated to those of substrate moisture, air temperature and microbial respiration. In fact N₂ fixation presented phases of different intensity which irregularly followed each other. Both litter and soil showed similar rates of N₂ fixation. Based on a C₂H₂:N₂ ratio of 3:1 0.8 Kg N ha^–1 y^–1 in each layer are fixed in the Pinus laricio forest, thus contributing to the N status of the soil in this nutrient–poor forest.     

Carbon storage,structure and composition of miombo woodlands in Tanzania’s Eastern Arc Mountains

We determine the aboveground biomass and carbon storage (ABGC) of trees and the herbaceous layer in miombo woodland in the Eastern Arc Mountains (EAM) of Tanzania. In four 1‐ha sample plots in Nyanganje and Kitonga Forests, we measured all trees ≥10 cm diameter alongside height and wood mass density. The plots contained an average of 20 tree species ha^?1 (range 11–29) and 344 stems ha^?1 (range 281–382) with Shannon diversity values of 1.05 and 1.25, respectively. We weighted nine previously published woody savannah allometric models based on whether: (i) the model was derived from the same geographical region; (ii) the model included tree height/wood mass density in addition to stem diameter; and (iii) sample size was used to fit the model. The weighted mean ABGC storage from the nine models range from 13.5 ± 2 to 29.8 ± 5 Mg ha^?1. Measured ABGC storage in the herbaceous layer, using the wet combustion method, adds 0.55 ± 0.02 Mg C ha^?1. Estimates suggest that EAM miombo woodlands store a range of 13–30 Mg ha^?1 of carbon. Although the estimates suggest that miombo woodlands store significant quantities of carbon, caution is required as this is the first estimate based on in situ data.     

Forest community structure and composition following containment treatments for the fungal pathogen oak wilt

In temperate oak forests in Ohio, USA, we examined variability in forest communities within containment treatment sites for oak wilt (Bretziella fagacearum), a fungal pathogen lethal to susceptible oak species. Containment treatments included quarantine lines in soil for limiting belowground fungal spread and sanitation cutting of 1–3 mature black oak (Quercus velutina) trees within oak wilt infection patches. At 28 sites, we compared tree structure and understory plant communities across a gradient of 1- to 6-year-old treatments and reference forest (untreated and without evidence of oak wilt). While oak seedlings were abundant, oak saplings (1–10 cm in diameter) were absent. In contrast, many native understory plant community measures were highest in oak wilt treatments. Plant species richness 100 m^?2 doubled in treatments, regardless of age, compared with reference forest. Plant cover increased with treatment age, with 6-year-old treatments exhibiting 5?×?more cover than reference forest. Non-native plants averaged only a small proportion (<?0.12) of cover across treatments and reference forest. Variability in understory communities was mostly predictable using treatment age, tree canopy cover, and geographic location, as 20 of 25 understory measures had at least 72% of their variance modeled. While oak wilt treatments did not facilitate oak regeneration nor many conservation-priority species of open savanna-woodland habitats, the treatments did diversify and increase cover of native understory communities with minimal invasion of non-native plants.

     

Abundance and Movement of Understory Birds in a Maulino Forest Fragmented by Pine Plantations

Understory birds are especially vulnerable to habitat fragmentation because of the reduction in habitat quality and bird movement. We study the separate effects of understory, overstory and landscape on four understory birds (tapaculos), in Central Chile, comprising a landscape mosaic of pine (Pinus radiata D. Don) plantations and native Maulino forest fragments. We also determined whether habitats with poor understory could be barrier to tapaculos movements. Abundance was measured using stationary playbacks and habitat barrier through playbacks. Understory structure was the main factor that predicted tapaculos presence and abundance. Two species, the Andean Tapaculo (Scytalopus magellanicus fuscus Gmelin) and the Ochre-flanked Tapaculo (Eugralla paradoxa Kittlitz), were positively associated with dead pine branches and negatively to forest fragment size. Tapaculos were less abundant in mature native forest, but appeared willing to cross between different habitat types. However, the Chestnut-throated Huet-huet (Pteroptochos castaneus Philippi and Landbeck), did not move from forest fragments to pine with poor understory. Overall, tapaculos species varied in their response to fragmentation depending on their habitat selection and movement capacities.     

湿地松×洪都拉斯加勒比松遗传多样性的ISSR分析

杂交育种是产生遗传变异、表型变异及选择新变异的重要方法。然而系统发育不清晰,选择较近的亲缘关系亲本用于杂交子代往往表现出较低的遗传多样性。为探究湿地松、洪都拉斯加勒比松种间杂交后代遗传多样性水平,对8个湿地松×洪都拉斯加勒比松家系进行ISSR分析。利用10条引物共产生60个表达清晰可用于分析的标记,其中48个标记表现为多态性,占总标记数的80%; 湿加松各个家系多态位点百分率在5%～23.33%之间; 各个家系基因多样性指数在 0.015 2～0.087 2之间,Shannon指数的范围在 0.021 6～0.129 4之间(家系水平为 0.293 4)。8个家系间的基因分化系数G_st为0.743 5,即总的遗传变异中有74.35%的变异存在于家系间,家系内的遗传变异占总遗传变异的25.65%。采用UPGMA法对湿加松的8个家系进行了聚类分析,确定了各个家系之间的遗传亲缘关系。8个家系间的基因流N_m为 0.172 5,表明基因流处于较低水平。     

Mesograzers prefer mostly native seaweeds over the invasive brown seaweed <Emphasis Type="Italic">Sargassum muticum</Emphasis>

The destruction of wetlands due to afforestation areas is a common activity in temperate and subtropical regions in Southern America. The expansion of pine (Pinus elliottii Engelm.) in the Coastal Plain of Southern Brazil is critical and its impacts on aquatic biodiversity are little known. We tested the hypotheses that: (1) pine occurrence diminishes the macrophyte richness and changes the macrophyte composition in ponds; (2) beta-diversity between natural and pine ponds is determined mainly by species nestedness (species loss). Sampling was carried out from 2007 to 2009 in five ponds in pine invasion matrix and five ponds in native grassland matrix. In natural ponds, the total richness was 87 species, followed by 51 species in pine ponds. From the total richness, 42 species were shared between natural and pine ponds. The natural ponds were richer than the pine ponds along the entire study, and the composition of macrophyte species was different between natural and pine ponds. Comparing natural ponds with each other and pine ponds with each other, the species turnover (species replacement) was determinant for beta-diversity, however, when we compared natural and pine ponds, we found that nestedness and species turnover were equivalent for beta-diversity. The increase in the nestedness mechanism indicates that the pine occurrence implies in species loss in Southern Brazil ponds. The change of hydroperiod may be one of the causes for the macrophyte species loss. The removal of pine from areas destined to conservation in Southern Brazil is urgent as well as a proper management of pine plantations in order to minimise its expansions and impacts in the aquatic biodiversity, since 90% of its wetlands have been already lost.     

<Emphasis Type="Italic">Myrothecium verrucaria</Emphasis> – a potential biological control agent for the invasive ‘old world climbing fern’ (<Emphasis Type="Italic">Lygodium microphyllum</Emphasis>)

One of the greatest threats to the native ecosystems in any part of the world is the invasion and permanent colonization of ecosystems by non-native species. Florida is no exception to this biological invasion, and is currently colonized by an extensive variety of exotic plant species. Originally imported from Asia over 30 years ago, Old World Climbing Fern Lygodium microphyllum (Cavanilles) R. Brown) has become one of the most invasive and destructive weeds in southern Florida. To date different effective control measures of its growth and spread have not been successful; fire and herbicide applications that are currently employed are neither cost effective nor environmentally friendly. In light of the highly delicate ecosystem that is being affected by L. microphyllum, we tested the soil fungus Myrothecium verrucaria (Albertini and Schwein) Ditmar: Fr. for its pathogenicity on the invasive fern. In greenhouse studies the effect of two conidial concentrations of M. verrucaria on L. microphyllum was investigated. Plants were spray inoculated with M. verrucaria which resulted in successful disease development with leaf necrosis symptoms. The higher conidial concentration (1 × 10⁸ ml⁻¹) produced a disease index of approximately 3 on a scale of 0 to 4, day 24 postinitial inoculation, demonstrating the efficacy of this fungus as a severe retardant of Lygodium growth. Preliminary screening of selected native plant species for susceptibility to M. verrucaria showed low disease indices after repeated spray inoculations; the highest index attained was 0.4 by Slash pine (Pinus elliottii).     

草木灰对四种松属种子发芽和幼苗生长的影响

火干扰不仅影响森林生态系统的结构与功能,而且影响群落更新与演替。为了研究草木灰对4种松属种子萌芽和幼苗生长的影响,在湖南省株洲市黄丰桥林场采集马尾松、云南松、湿地松和火炬松种子,以马尾松次生林火烧迹地的草木灰为基质,设置对照和3个草木灰处理,进行播种试验及生长观测。结果表明:(1)草木灰处理下4个物种的种子发芽率比对照试验低,并呈现随草木灰含量的增加而降低的趋势,低草木灰含量处理马尾松种子发芽率不及对照一半,中、高草木灰含量处理发芽率更低;云南松、湿地松和火炬松种子发芽率规律类似于马尾松,而高草木灰含量处理发芽率为0。(2)培养皿播种平均发芽时间比花盆播种长,无论草木灰处理还是培养条件(培养皿或花盆),马尾松和云南松种子平均发芽时间比湿地松和火炬松短。(3)4个物种种子播种14周后,对照试验中马尾松和云南松幼苗死亡率最低,而火炬松和湿地松幼苗死亡率相对增加。(4)播种14周后不同试验处理4个物种幼苗生长差异不明显。火炬松、湿地松、云南松和马尾松幼苗的单株平均干重分别达0.038、0.031、0.027、0.024 g。各物种叶干重按降序排列依次是火炬松(0.026 g)湿地松(0.019 g)云南松(0.017 g)马尾松(0.016 g),根和茎的干重比重相当,约占对应物种幼苗叶干重的三分之一。研究表明以草木灰为培养基质,马尾松和云南松种子的发芽率较高,平均发芽时间较短,更适合作为火烧迹地植被恢复先锋树种,为火干扰后选择人工促进天然更新树种提供参考。