Response of soricid populations to repeated fire and fuel reduction treatments in the southern Appalachian Mountains

Fuel hazards have increased in forests across the United States because of fire exclusion during the 20th century. Treatments used to reduce fuel buildup may affect wildlife, such as shrews, living on the forest floor, especially when treatments are applied repeatedly. From mid-May to mid-August 2006 and 2007, we used drift fences with pitfall traps to capture shrews in western North Carolina in 3 fuel reduction treatment areas [(1) twice-burned (2003 and 2006), (2) mechanical understory cut (2002), and (3) mechanical understory cut (2002) followed by 2 burns (2003 and 2006)] and a control. We captured 77% fewer southeastern shrews (Sorex longirostris) in mechanical + twice-burned treatment areas than in mechanical treatment areas in 2006, but southeastern shrew captures did not differ among treatment areas in 2007. Total shrew captures did not differ among treatment areas in either year. Decreases in leaf litter, duff depth, and canopy cover in mechanical + twice-burned treatment areas may have decreased ground-level moisture, thereby causing short-term declines in southeastern shrew captures. Prescribed fire or mechanical fuel reduction treatments in the southern Appalachian Mountains did not greatly affect shrew populations, though the combination of both treatments may negatively affect some shrew species, at least temporarily.     

江西裸子植物区系分析

江西裸子植物自然分布7科22属32种1变种(其中中国特有科1个为银杏科,特有属有银杏属、金钱松属、杉木属、水松属、白豆杉属等5个,特有种有银杏、华东黄杉、长苞铁杉、金钱松、水松等20种),分别占全国58.3%、53.66%、13.75%。江西有6个单型属,分别占世界和全国35.3%和50%。属分布区类型中以亚热带到温带成分和特有成分为主,分别占江西全部属的50%和22.72%。总结出江西裸子植物种级分布区亚型有17个,其中从西南或喜马拉雅到华东的分布就有9个分布式样18种,占总种数的54.5%。江西现代裸子植物通过南岭山脉、武夷山脉和罗霄山脉等与周边地区联系密切,相似性系数显示江西裸子植物区系与华南、华中、西南联系密切(相似系数皆大于50%),与华北比较疏远(相似系数为6.1%)。     

The impact of landscape disturbance on grizzly bear habitat use in the Foothills Model Forest,Alberta, Canada

The Rocky Mountains in Alberta, Canada are subject to a growing number of human activities that cause landscape disturbances. This region is important for large carnivore species such as grizzly bears, whose population decline is a serious management concern. Understanding the impact of landscape disturbance on grizzly bear habitat use is necessary to effectively manage this region and beyond. The goal of this research is to explore the spatial–temporal pattern of habitat use and to characterize the impact of disturbance on use through time. Research was conducted using radio-telemetry location data of female grizzly bears from 1999 to 2003. Kernel home ranges were created annually for three foraging seasons: hypophagia, early hyperphagia, and late hyperphagia. For each season, locations (30 m × 30 m grid cells) were characterized by the temporal persistence or variability in annual use by grizzly bears. Spatial–temporal trends were then compared for disturbed and undisturbed landscapes. Results indicate that in some foraging seasons, particularly hypophagia, the grizzly bear population's use of disturbed areas was proportionally higher than use in undisturbed areas. In other foraging seasons the trends are less clear, but all show instances of preferential selection of disturbed areas. Given that grizzly bear mortality tends to rise when bears use disturbed areas, this preferential selection of disturbed areas is a management concern. To enhance conservation efforts it may be beneficial to control human use in high-quality habitats. This protection may be most important for high-quality habitats used in the spring, as bears appeared to use smaller areas during this period.     

浙江产国家重点保护野生植物(第一批) 的分布与保护现状

1999年8月4日国家林业局和农业部发布了国家重点保护野生植物（第一批）名录，对产于浙江的11种一级保护植物和40种二级保护植物在浙江省的分布，保护和研究现状调查表明，浙西南部是浙江产国家重点保护野生植物的分布中心，分布有百山祖冷杉，九龙山榧二个浙江特有种，浙西北部是其又一分布中心，分布有天目铁牛，羊角槭二个浙江物有种，大部分保护植物分布于百山祖，凤阳山，九龙山，乌岩岭，天目山，清凉峰，九王山等自然保护区内。浙东地区种类相对较少，但有天台鹅耳枥、普陀鹅耳枥、普陀樟三个浙江特有种。浙江产国家重点保护野植物集中分布在海拔250－1250m，最高限海拔为1700m， 珍稀濒危植物的保护与繁殖等方面做了大量的工作，取得了丰硕成果，并就开展和加 强资源保护工作提出几点建议。     

An indicator of tree migration in forests of the eastern United States

Changes in tree species distributions are a potential impact of climate change on forest ecosystems. The examination of tree species shifts in forests of the eastern United States largely has been limited to simulation activities due to a lack of consistent, long-term forest inventory datasets. The goal of this study was to compare current geographic distributions of tree seedlings (trees with a diameter at breast height ≤2.5 cm) with biomass (trees with a diameter at breast height > 2.5 cm) for sets of northern, southern, and general tree species in the eastern United States using a spatially balanced, region-wide forest inventory. Compared to mean latitude of tree biomass, mean latitude of seedlings was significantly farther north (>20 km) for the northern study species, while southern species had no shift, and general species demonstrated southern expansion. Density of seedlings relative to tree biomass of northern tree species was nearly 10 times higher in northern latitudes compared to southern latitudes. For forest inventory plots between 44° and 47° north latitude where southern tree species were identified, their biomass averaged 0.46 tonnes/ha while their seedling counts averaged 2600 ha⁻¹. It is hypothesized that as northern and southern tree species together move northward due to greater regeneration success at higher latitudes, general species may fill their vacated niches in southern locations. The results of this study suggest that the process of northward tree migration in the eastern United States is currently underway with rates approaching 100 km/century for many species.     

河南鸡公山自然保护区鸟类多样性与分布特征

2010年冬季与2011年春夏季,采用样线法对位于豫鄂交界处的鸡公山鸟类多样性进行调查。结合历史资料,鸡公山共有鸟类17目48科206种;其中国家重点保护动物7科23种,特有种或主要分布在我国的鸟类2科3种。留鸟61种,夏候鸟63种,冬候鸟31种,旅鸟51种。古北界鸟类88种,东洋界鸟类49种,广布种69种。研究区域具有古北界与东洋界种混杂的特点,但古北种鸟类占优势,分布型以北方鸟类为主。基于科属水平上的G-F指数计算结果显示:鸡公山的F指数(28.96)与G指数(4.56)低于邻近的伏牛山(30.31,4.70)和秦岭地区(32.34,4.87)鸟类F指数、G指数;F-G指数值与秦岭鸟类相同,均为0.85,均高于伏牛山F-G指数(0.84),显示鸡公山在鸟纲科属水平上与秦岭鸟类多样性相似,且具有相对较高的鸟类多样性。     

Thinning and chipping small-diameter ponderosa pine changes understory plant communities on the Colorado Front Range

Novel fire mitigation treatments that chip harvested biomass on site are increasingly prescribed to reduce the density of small-diameter trees, yet the ecological effects of these treatments are unknown. Our objective was to investigate the impacts of mechanical thinning and whole tree chipping on Pinus ponderosa (ponderosa pine) regeneration and understory plant communities to guide applications of these new fuel disposal methods. We sampled in three treatments: (1) unthinned forests (control), (2) thinned forests with harvested biomass removed (thin-only), and (3) thinned forests with harvested biomass chipped and broadcast on site (thin + chip). Plots were located in a ponderosa pine forest of Colorado and vegetation was sampled three to five growing seasons following treatment. Forest litter depth, augmented with chipped biomass, had a negative relationship with cover of understory plant species. In situ chipping often produces a mosaic of chipped patches tens of meters in size, creating a range of woodchip depths including areas lacking woodchip cover within thinned and chipped forest stands. Thin-only and thin + chip treatments had similar overall abundance and species richness of understory plants at the stand scale, but at smaller spatial scales, areas within thin + chip treatments that were free of woodchip cover had an increased abundance of understory vegetation compared to all other areas sampled. Relative cover of non-native plant species was significantly higher in the thin-only treatments compared to control and thin + chip areas. Thin + chip treated forests also had a significantly different understory plant community composition compared to control or thin-only treatments, including an increased richness of rhizomatous plant species. We suggest that thinning followed by either chipping or removing the harvested biomass could alter understory plant species composition in ponderosa pine forests of Colorado. When considering post-treatment responses, managers should be particularly aware of both the depth and the distribution of chipped biomass that is left in forested landscapes.     

Riparian forest and instream large wood characteristics,West Branch Sheepscot River,Maine, USA

This study examined riparian forest and instream large wood characteristics in a 2.7 km reach of the West Branch of the Sheepscot River in Maine in order to increase our basic knowledge of these components in a system that is known to have undergone multiple land conversion. The West Branch is approximately 40 km long, drains a 132 km² watershed and is vitally important to the remnant population of Atlantic salmon (Salmo salar) and other native species. The riparian forest is comprised of relatively small trees with a mean DBH of 21 cm (SD ± 10.92) with 56% of the trees having a DBH <20 cm. Balsam fir (Abies balsamea) and red maple (Acer rubrum) are the most common species (54%), and 75% of all trees are short-lived, small diameter species. These data suggest the riparian forest in the West Branch Sheepscot River is dominated by young forest stands, a legacy of land use. During a survey conducted in 2005, 210 pieces of large woody debris (LWD) were identified in the study reach; an average of 78 pieces km⁻¹. The total volume of pieces was 8.5 m³ or 3.2 m³ km⁻¹ (LWD in this study is defined as pieces ≥10 cm in diameter and >2 m in length). The mean diameter of LWD was 17 cm with 75% of all pieces having a diameter <20 cm. Most pieces were oriented parallel or nearly parallel to the channel and did not appear to influence channel morphology. In contrast, larger pieces were more often in perpendicular or nearly perpendicular orientations, and were more likely to have a pool-forming function. Overall, the reach has low levels of stable large wood, which do not have a major influence on stream habitats.     

河南天目山森林种子植物区系研究

经调查,河南天目山有森林种子植物1 824种,隶属于155科,707属。种子植物区系有如下特点:种类组成丰富,优势现象明显;植物区系复杂多样,以温带分布为主,热带成分较为丰富,南北过渡特征明显;在属的层次上,与各大陆的温带、热带保持着较为广泛的联系;在种的水平上,通过华东与东亚植物区系联系密切;天目山植物区系起源古老,有单种属植物40种,中国特有属25个,国家珍稀濒危保护植物20种,均为第三纪植物区系成分。     

Effects of human disturbances and plant invasion on liana community structure and relationship with trees in the Tinte Bepo forest reserve,Ghana

There are conflicting reports on the role of disturbances in maintaining liana community structure, and in determining their relationship with trees. The effects of plant invasion on these attributes of lianas are not known. The study investigated the effects of human disturbances and plant invasion on liana community structure and relationship with trees in the Tinte Bepo forest reserve, Ghana, in three distinct forest types to reflect both human disturbances and invasion: Undisturbed, Disturbed-Invaded and Disturbed Forests (UF, DIF and DF respectively). Trees ≥10 cm dbh were identified and their dbh measured in two 0.25 ha plots in each forest type. The trees were examined for the presence of lianas (≥2 cm dbh) and their dbh measured. A total of 380 lianas ≥2 cm dbh belonging to 20 genera and 12 families were identified in the 1.5 ha forest. Twelve liana species were unique to the DIF suggesting the probable positive influence of plant invasion on their colonisation. Liana density differed significantly across the forest types (df = 2, p = 0.043) with the UF recording the greatest number. The mean liana stem diameter and basal area were greater in the DF. Large diameter lianas were absent in the UF. Tree density and number of trees hosting lianas were greater in the UF followed by the DIF and DF. Liana infestation was generally high with 90% in the DF, 88.2% in the UF, and 85.7% in the DIF. Both liana load per tree species and mean liana load per infested tree were highest in the UF followed by the DIF and then the DF. Liana density was highly dependent on tree density in all the forest types (df = 1, r² = 0.50, p = 0.007; df = 1, r² = 0.99, p = 0.000 and df = 1, r² = 0.72, p = 0.000 in the UF, DIF and DF respectively). There was a significant positive relationship between liana dbh and host dbh in the UF (df = 1, r² = 0.096, p = 0.000), DIF (df = 1, r² = 0.11, p = 0.000) and DF (df = 1, r² = 0.16, p = 0.008). There was no significant relationship between host dbh and liana loads in all the forest types.     

Understory vegetation in old-growth and second-growth Tsuga canadensis forests in western Massachusetts

We compared the understory communities (herbs, shrubs, and tree seedlings and saplings) of old-growth and second-growth eastern hemlock forests (Tsuga canadensis) in western Massachusetts, USA. Second-growth hemlock forests originated following clear-cut logging in the late 1800s and were 108–136 years old at the time of sampling. Old-growth hemlock forests contained total ground cover of herbaceous and shrub species that was approximately 4 times greater than in second-growth forests (4.02 ± 0.41%/m² versus 1.06 ± 0.47%/m²) and supported greater overall species richness and diversity. In addition, seedling and sapling densities were greater in old-growth stands compared to second-growth stands and the composition of these layers was positively correlated with overstory species composition (Mantel tests, r > 0.26, P < 0.05) highlighting the strong positive neighborhood effects in these systems. Ordination of study site understory species composition identified a strong gradient in community composition from second-growth to old-growth stands. Vector overlays of environmental and forest structural variables indicated that these gradients were related to differences in overstory tree density, nitrogen availability, and coarse woody debris characteristics among hemlock stands. These relationships suggest that differences in resource availability (e.g., light, moisture, and nutrients) and microhabitat heterogeneity between old-growth and second-growth stands were likely driving these compositional patterns. Interestingly, several common forest understory plants, including Aralia nudicaulis, Dryopteris intermedia, and Viburnum alnifolium, were significant indicator species for old-growth hemlock stands, highlighting the lasting legacy of past land use on the reestablishment and growth of these common species within second-growth areas. The return of old-growth understory conditions to these second-growth areas will largely be dependent on disturbance and self-thinning mediated changes in overstory structure, resource availability, and microhabitat heterogeneity.     

Carbon and nitrogen in forest floor and mineral soil under six common European tree species

The knowledge of tree species effects on soil C and N pools is scarce, particularly for European deciduous tree species. We studied forest floor and mineral soil carbon and nitrogen under six common European tree species in a common garden design replicated at six sites in Denmark. Three decades after planting the six tree species had different profiles in terms of litterfall, forest floor and mineral soil C and N attributes. Three groups were identified: (1) ash, maple and lime, (2) beech and oak, and (3) spruce. There were significant differences in forest floor and soil C and N contents and C/N ratios, also among the five deciduous tree species. The influence of tree species was most pronounced in the forest floor, where C and N contents increased in the order ash = lime = maple < oak = beech ? spruce. Tree species influenced mineral soil only in some of the sampled soil layers within 30 cm depth. Species with low forest floor C and N content had more C and N in the mineral soil. This opposite trend probably offset the differences in forest floor C and N with no significant difference between tree species in C and N contents of the whole soil profile. The effect of tree species on forest floor C and N content was primarily attributed to large differences in turnover rates as indicated by fractional annual loss of forest floor C and N. The C/N ratio of foliar litterfall was a good indicator of forest floor C and N contents, fractional annual loss of forest floor C and N, and mineral soil N status. Forest floor and litterfall C/N ratios were not related, whereas the C/N ratio of mineral soil (0–30 cm) better indicated N status under deciduous species on rich soil. The results suggest that European deciduous tree species differ in C and N sequestration rates within forest floor and mineral soil, respectively, but there is little evidence of major differences in the combined forest floor and mineral soil after three decades.     

Forest thinning and subsequent bark beetle-caused mortality in Northeastern California

The Warner Mountains of northeastern California on the Modoc National Forest experienced a high incidence of tree mortality (2001–2007) that was associated with drought and bark beetle (Coleoptera: Curculionidae, Scolytinae) attack. Various silvicultural thinning treatments were implemented prior to this period of tree mortality to reduce stand density and increase residual tree growth and vigor. Our study: (1) compared bark beetle-caused conifer mortality in forested areas thinned from 1985 to 1998 to similar, non-thinned areas and (2) identified site, stand and individual tree characteristics associated with conifer mortality. We sampled ponderosa pine (Pinus ponderosa var ponderosa Dougl. ex Laws.) and Jeffrey pine (Pinus jeffreyi Grev. and Balf.) trees in pre-commercially thinned and non-thinned plantations and ponderosa pine and white fir (Abies concolor var lowiana Gordon) in mixed conifer forests that were commercially thinned, salvage-thinned, and non-thinned. Clusters of five plots (1/50th ha) and four transects (20.1 × 100.6 m) were sampled to estimate stand, site and tree mortality characteristics. A total of 20 pre-commercially thinned and 13 non-thinned plantation plot clusters as well as 20 commercially thinned, 20 salvage-thinned and 20 non-thinned mixed conifer plot clusters were established. Plantation and mixed conifer data were analyzed separately. In ponderosa pine plantations, mountain pine beetle (Dendroctonus ponderosae Hopkins) (MPB) caused greater density of mortality (trees ha⁻¹ killed) in non-thinned (median 16.1 trees ha⁻¹) compared to the pre-commercially thinned (1.2 trees ha⁻¹) stands. Percent mortality (trees ha⁻¹ killed/trees ha⁻¹ host available) was less in the pre-commercially thinned (median 0.5%) compared to the non-thinned (5.0%) plantation stands. In mixed conifer areas, fir engraver beetles (Scolytus ventralis LeConte) (FEN) caused greater density of white fir mortality in non-thinned (least square mean 44.5 trees ha⁻¹) compared to the commercially thinned (23.8 trees ha⁻¹) and salvage-thinned stands (16.4 trees ha⁻¹). Percent mortality did not differ between commercially thinned (least square mean 12.6%), salvage-thinned (11.0%), and non-thinned (13.1%) mixed conifer stands. Thus, FEN-caused mortality occurred in direct proportion to the density of available white fir. In plantations, density of MPB-caused mortality was associated with treatment and tree density of all species. In mixed conifer areas, density of FEN-caused mortality had a positive association with white fir density and a curvilinear association with elevation.     

Distribution, habitat and biomass of Pittosporum undulatum, the most important woody plant invader in the Azores Archipelago

Pittosporum undulatum Ventenat (Pittosporaceae) is a tree or shrub native to Australia introduced in the Azores Islands in the 19th century, presently naturalized in the nine islands. According to a random survey of vascular plants in the Azores, the invader is present throughout the archipelago, in 62% of 547 1-km² samples. It was found in pure or mixed stands, forming groups and also as isolated trees. P. undulatum was frequently found in native scrubland (62%), mixed woodland (39%) and hedgerows (25%). The altitudinal range extended from sea level up to about 800 m a.s.l., with the highest frequency between 100 and 400 m. The woody species more strongly associated with P. undulatum included characteristic native and endemic species as well as non-indigenous and invasive taxa. Based on a forest inventory, 49% of the forested area in the Azores, about 24,000 ha, is occupied by P. undulatum. Considerable areas inside Island Natural Parks are covered by this species. The estimated annual P. undulatum biomass production in the Azores might range from only about 150 Mg in the small island of Corvo up to more than 60,000 Mg in Pico Island. The heating value of its wood and its chemical composition make it a good candidate for use in combustion or gasification processes. Since there are no resources available to control this large-scale invasion, using P. undulatum biomass for energy production might be an important factor to stimulate the progressive and sustainable cutting of its stands and its replacement by Macaronesian species.     

Profound impoverishment of the large-tree stand in a hyper-fragmented landscape of the Atlantic forest

Large tree species have a disproportional influence on the structure and functioning of tropical forests, but the forces affecting their long-term persistence in human-dominated landscapes remain poorly understood. Here we test the hypothesis that aging forest edges and small fragments (3.4–295.7 ha) are greatly impoverished in terms of species richness and abundance of large trees in comparison to core areas of forest interior. The study was conducted in a hyper-fragmented landscape of the Atlantic forest, northeast Brazil. Large tree species were quantified by recording all trees (DBH ≥ 10 cm) within fifty-eight 0.1-ha plots distributed in three forest habitats: small forest fragments (n = 28), forest edges (n = 10), and primary forest interior areas within an exceptional large forest remnant (n = 20). Large tree species and their stems ≥10 cm DBH were reduced by half in forest edges and fragments. Moreover, these edge-affected habitats almost lacked large-stemmed trees altogether (0.24 ± 0.27% of all stems sampled), and very tall trees were completely absent from forest edges. In contrast, large trees contributed to over 1.5% of the whole stand in forest interior plots (2.9 ± 2.8%). Habitats also differed in terms of tree architecture: relative to their DBH trees were on average 30% shorter in small fragments and forest edges. Finally, an indicator species analysis yielded an ecological group of 12 large tree species that were significantly associated with forest interior plots, but were completely missing from edge-affected habitats. Our results suggest a persistent and substantial impoverishment of the large-tree stand, including the structural collapse of forest emergent layer, in aging, hyper-fragmented landscapes.     

Aboveground biomass and nutrient accumulation dynamics in young black alder, silver birch and Scots pine plantations on reclaimed oil shale mining areas in Estonia

The growth, aboveground biomass production and nutrient accumulation in black alder (Alnus glutinosa (L.) Gaertn.), silver birch (Betula pendula Roth.) and Scots pine (Pinus sylvestris L.) plantations during 7 years after planting were investigated on reclaimed oil shale mining areas in Northeast Estonia with the aim to assess the suitability of the studied species for the reclamation of post-mining areas. The present study revealed changes in soil properties with increasing stand age. Soil pH and P concentration decreased and soil N concentration increased with stand age. The largest height and diameter of trees, aboveground biomass and current annual production occurred in the black alder stands. In the 7-year-old stands the aboveground biomass of black alder (2100 trees ha⁻¹) was 2563 kg ha⁻¹, in silver birch (1017 trees ha⁻¹) and Scots pine (3042 trees ha⁻¹) stands respective figures were 161 and 1899 kg ha⁻¹. The largest amounts of N, P, K accumulated in the aboveground part were in black alder stands. In the 7th year, the amount of N accumulated in the aboveground biomass of black alder stand was 36.1 kg ha⁻¹, the amounts of P and K were 3.0 and 8.8 kg ha⁻¹, respectively. The larger amounts of nutrients in black alder plantations are related to the larger biomass of stands. The studied species used N and P with different efficiency for the production of a unit of biomass. Black alder and silver birch needed more N and P for biomass production, and Scots pine used nutrients most efficiently. The present study showed that during 7 years after planting, the survival and productivity of black alder were high. Therefore black alder is a promising tree species for the reclamation of oil shale post-mining areas.     

Large wood abundance,distribution and mobilization in a third order Coastal mountain range river system,southern Chile

Large wood (LW) abundance, longitudinal distribution and mobilization were studied in the Vuelta de la Zorra channel draining a third order catchment located in the Coastal mountain range of southern Chile. Seventy-five percent of the 586.8 ha study catchment area is covered by evergreen native rainforests, 24% by Eucalyptus nitens plantations and the remaining 1% are different sites were native tree and shrub species are regenerating in areas that were prepared for forest replacement in the late 1980s but finally left unplanted. In a segment, 1557 m in length, surveyed between November 2008 and February 2009, a total of 484 pieces representing 181 m³ of LW were measured. Using bankfull width and length this volume corresponds to 109 m³ ha⁻¹ or 11.6 m³ 100 m⁻¹. LW was distributed along the channel in correlation with bankfull width. The channel segment was re-surveyed in December 2009 and we found that after one winter season 12% of the LW were transported downstream the river channel and 9 new wood elements were recruited. The LW traveled distance and traveled distance/piece diameter ratio decreased with increasing piece length/mean bankfull ratio. These results contribute to understand the complexity of LW abundance, mobilization and recruitment processes, and their effects on channel morphology, sediment routing and ecology in Chilean catchments.     

Liana species richness,abundance and relationship with trees in the Bobiri forest reserve,Ghana: Impact of management systems

Forest management practices which may represent various forms of disturbance regimes could influence liana species richness, abundance and relationship with their hosts. The study sought to determine the impacts of three management systems, namely, the Selection, Tropical Shelterwood and Post Exploitation Systems (SS, TSS and PES respectively) on liana species richness, abundance and relationship with trees in the Bobiri forest reserve, Ghana. Lianas with dbh ≥ 2 cm found on trees with dbh ≥ 10 cm were enumerated in 1 ha plot each in the SS, TSS and PES. All trees (dbh ≥ 10 cm) within the plots that did not carry lianas were also enumerated. A total of 640 liana individuals belonging to 27 species, 22 genera and 13 families were identified in the management systems. Griffonia simplicifolia (Vahl ex DC.) Baill., Motandra guineensis (Thonn.) A.DC. and Calycobolus africanus (G.Don) Heine were the abundant species in all the management systems. Unlike in SS, lianas in the TSS and PES were dominated by a few species. Larger diameter lianas were more abundant in the PES (32%) compared with the SS (18.3%) and the PES (13.1%). Liana diversity (H′) (species richness and abundance) was quantitatively higher in the SS (2.8) than the TSS (2.2) and the PES (2.0). The numbers of lianas carried by tree species differed significantly in the management systems (p < 0.001 each). Liana infestation in the forest was high. The level of liana infestation did not reflect the extent of liana load per tree in the management systems. Larger trees carried significantly more liana individuals than smaller trees in the PES (p = 0.019, r² = 0.15). There was a positive significant relationship between host dbh and liana dbh in the PES (p < 0.001, r² = 0.23) and TSS (p = 0.024, r² = 0.11). Tree diversity appeared to have influenced liana species richness and abundance.     

Radiation use efficiency in adjacent hardwood and pine forests in the southern Appalachians

The efficiency with which trees convert photosynthetically active radiation (PAR) to biomass has been shown to be consistent within stands of an individual species, which is useful for estimating biomass production and carbon accumulation. However, radiation use efficiency (?) has rarely been measured in mixed-species forests, and it is unclear how species diversity may affect the consistency of ?, particularly across environmental gradients. We compared aboveground net primary productivity (ANPP), intercepted photosynthetically active solar radiation (IPAR), and radiation use efficiency (? = ANPP/IPAR) between a mixed deciduous forest and a 50-year-old white pine (Pinus strobus L.) plantation in the southern Appalachian Mountains. Average ANPP was similar in the deciduous forest (11.5 Mg ha⁻¹ y⁻¹) and pine plantation (10.2 Mg ha⁻¹ y⁻¹), while ? was significantly greater in the deciduous forest (1.25 g MJ⁻¹) than in the white pine plantation (0.63 g MJ⁻¹). Our results demonstrate that late-secondary hardwood forests can attain similar ANPP as mature P. strobus plantations in the southern Appalachians, despite substantially less annual IPAR and mineral-nitrogen availability, suggesting greater resource-use efficiency and potential for long-term carbon accumulation in biomass. Along a 260 m elevation gradient within each forest there was not significant variation in ?. Radiation use efficiency may be stable for specific forest types across a range of environmental conditions in the southern Appalachian Mountains, and thus useful for generating estimates of ANPP at the scale of individual watersheds.