Native Saplings Research Articles

World Environment Day 2024 Initiatives in Bayelsa State: Promoting Environmental Stewardship and Sustainable Practices - A Collaboration Between Federal University Otuoke, Niger Delta University, and the Nigerian Environmental Society

Environmental degradation has emerged as a critical global issue, significantly impacting ecosystems and human health, particularly in low and middle-income countries like Nigeria. The need for comprehensive and sustainable environmental management practices is paramount to address these challenges effectively. This study aims to assess the current state of environmental degradation in Bayelsa State, Nigeria, and evaluate the effectiveness of initiatives undertaken during World Environment Day (WED) 2024 to promote environmental stewardship and sustainable practices. The study employed a mixed-method approach, including field observations, community surveys, and analysis of environmental data. Activities during WED 2024, such as tree planting, educational lectures, and site visits, were evaluated to determine their impact on raising environmental awareness and promoting sustainable practices. The activities conducted during WED 2024 significantly increased community awareness about environmental issues and the importance of sustainable practices. The planting of 500 native saplings contributed to combating deforestation and soil erosion, while educational lectures and site visits provided residents with practical knowledge and insights into environmental conservation. The initiatives undertaken during WED 2024 in Bayelsa State have laid a strong foundation for fostering a culture of environmental stewardship. By engaging the community and promoting sustainable practices, these efforts have set a positive precedent for future conservation activities, contributing to a more resilient and sustainable environment. To build on the success of these initiatives, it is recommended that the Bayelsa State Government enact stricter environmental laws and regulations. Increased environmental advocacy by the Nigerian Environmental Society and other stakeholders is crucial, along with adopting sustainable agricultural practices and improving waste management systems. This study highlights the critical role of community engagement and education in promoting environmental conservation. The findings demonstrate that targeted initiatives, such as those undertaken during WED 2024, can significantly enhance environmental awareness and drive sustainable practices, contributing to the overall resilience and sustainability of ecosystems in Bayelsa State and beyond.

Effects of restoration on tree communities and carbon storage in rainforest fragments of the Western Ghats, India

AbstractEcological restoration is a leading strategy for reversing biodiversity losses and enhancing terrestrial carbon sequestration in degraded tropical forests. There have been few comprehensive assessments of recovery following restoration in fragmented forest landscapes, and the efficacy of active versus passive (i.e., natural regeneration) restoration remains unclear. We examined 11 indicators of forest structure, tree diversity and composition (adult and sapling), and aboveground carbon storage in 25 pairs of actively restored (AR; 7–15 yr after weed removal and mixed‐native tree species planting) and naturally regenerating (NR) plots within degraded rainforest fragments, and in 17 less‐disturbed benchmark (BM) rainforest plots in the Western Ghats, India. We assessed the effects of active restoration on the 11 indicators and tested the hypothesis that the effects of active restoration increase with isolation from contiguous and relatively intact rainforests. Active restoration significantly increased canopy cover, adult tree and sapling density, adult and sapling species density (overall and late‐successional), compositional similarity to benchmarks, and aboveground carbon storage, which recovered 14–82% toward BM targets relative to NR baselines. By contrast, tree height–diameter ratios and the proportion of native saplings did not recover consistently in actively restored forests. The effects of active restoration on canopy cover, species density (adult), late‐successional species density (adult and sapling), and species composition, but not carbon storage, increased with isolation across the fragmented landscape. Our findings show that active restoration can promote recovery of forest structure, composition, and carbon storage within 7–15 yr of restoration in degraded tropical rainforest fragments, although the benefits of active over passive restoration across fragmented landscapes would depend on indicator type and may increase with site isolation. These findings on early stages of recovery suggest that active restoration in ubiquitous fragmented landscapes of the tropics could complement passive restoration of degraded forests in less fragmented landscapes, and protection of intact forests, as a key strategy for conserving biodiversity and mitigating climate change.

Effect of Compost and Hydroabsorbent Polymer on Tree Growth and Soil Properties in a Tropical Urban Environment

ABSTRACTHorticultural application of hydroabsorbent polymer (HP) has drawn research attention due to its perceived benefits to plant growth. Few studies have compared the use of compost and HP amendments on tree establishment in tropical urban environments. An experiment was conducted to assess the effect of compost (40% v v–1) and HP (3 and 5 kg m–3) on the growth of two native tree saplings (Calophyllum soulattri and Syzygium myrtifolium) in loamy and sandy soils. The HP treatments significantly affected soil pH and extractable phosphorus (P) and potassium (K), whereas combined application of compost and HP (5 kg m–3) resulted in significantly higher nitrogen (N) in both soil types. Plant diameter and height were significantly higher following HP application. This experiment demonstrates the efficacy of HP that can cater the plant requirements at the initial growth stages which are crucial for their successful establishment in tropic urban degraded soils.

Characteristics of tropical human-modified forests after 20\xa0years of natural regeneration

BackgroundAbandoned human-modified forests are refuges for remnant biodiversity. However, there are very few studies on the biodiversity and regeneration of native species in human-modified forests which are rich in exotic trees. Our research aim is to evaluate the regeneration status and biodiversity of two adjacent human-modified forests. The two forests have distinct overstorey exotic species richness prior to abandonment: one is an exotic tree plantation low in species richness, and the other is an exotic arboretum high in species richness. The original management practices of the two forests have been neglected for more than 20 years. A primary forest was selected as a reference forest to compare their diversity and regeneration status. We asked: (1) Is there a structural difference among the three forests? (2) What are the proportions of native saplings in the human-modified forests? (3) Are the introduced exotic species able to naturalize?ResultsWe recorded 1316 individuals from 88 species, belonging to 69 genera and 34 families in the three forests [each sampled 16 quadrats (10 m × 5 m)]. Both human-modified forests were similar in their height structure, diameter structure, and sapling density, but differed in species diversity (characterized by rarefaction curves) and floristic composition (indicated by a quantitative similarity index). In the arboretum, only 50% of the sapling individuals were native. Surprisingly, when sampling efforts were standardized, the arboretum had higher native sapling species richness than the exotic species-poor plantation. Moreover, both human-modified forests had conserved a few rare and endemic species. Nevertheless, some exotic species in the arboretum had escaped to the nearby plantation.ConclusionsAfter 20 years of abandonment, the two human-modified forests had converged in structure, but not in diversity patterns of native saplings. This could be due to that the diversity of exotic overstorey composition can influence the natural regeneration of understorey plants. Our study also raised concerns about conserving native species and managing naturalized exotic species in these human-modified forests.

The Effect of Simulated Nitrogen Deposition on the Emission of Carbonyl Compounds from Ormosia pinnata and Cinnamomum burmannii

The Effect of Simulated Nitrogen Deposition on the Emission of Carbonyl Compounds from Ormosia pinnata and Cinnamomum burmannii Elevated anthropogenic nitrogen (N) deposition has become a limiting factor for plants instead of a nutrient for its dramatic rising at globally scale, which greatly affects the process of carbon (C) cycle from individual plant to ecosystem, and even global levels. It could affect biogenic carbonyl emissions as an important component of carbon pool from plants, but this aspect has not yet been investigated. In this study, we performed a simulated N deposition experiment (100 kg N•ha-1•y-1) on two native tree saplings planted in a nursery in South China. Results showed that three main biogenic carbonyls, i.e. formaldehyde, acetaldehyde, and acetone from tree leaves all had distinct seasonal variations, with much higher emission rates in the wet season than in the dry season. Elevated N addition significantly depressed the emission of biogenic carbonyls in the dry season, but not in the wet season. No big differences were observed in carbonyls emissions from the two tree species responding to N deposition both in the wet season and in the dry season. Thus, we concluded that N deposition might drive plants to change carbon allocation and reduce carbon loss when as a limiting factor in the dry season. This finding is of significance for the theory of carbon allocation and plant adaptability strategy under elevated N deposition.

Herbicide application as a habitat restoration tool: impact on native island plant communities

AbstractQuestionsWhich physical or chemical removal method is most effective in controlling woody invasive alien plant (IAP) species in sensitive conservation areas, while minimizing the impact on different life stages of native plant communities? Is there a distinct influence of removal method on successional trajectories of post‐treatment seedling communities?LocationMid‐altitude inselbergs, Mahé, Seychelles, Indian Ocean.MethodsWe conducted two field experiments. First, to test the effects of four IAP control methods (cut, 5%, 10%, 15% Tordon 101 herbicide concentration) on ten woody IAP species, we treated a total of 320 adults and monitored mortality for 18 wk. Second, we set up five blocks each with four plots (4 m × 4 m) at three inselberg sites (N = 60 plots) and recorded the response of seedlings, saplings and adults of all native and IAP species to four Tordon 101 (a.i. picloram and 2,4‐D) herbicide and manual control treatments (cut, cut‐stump, foliar spray, control) over 22 mo. Treatment effects were analysed with GLMM models, and community responses were investigated with NMDS and multivariate ANOVA.ResultsThe first experiment showed that IAP mortality (98.3%) was similar across all three herbicide concentrations, but markedly higher than mortality of cut plants (42.5%). In the second experiment, abundance, but not diversity, of native seedlings declined with herbicide application in the first 6 mo after treatment. Ordination analysis showed that seedling communities experienced high turnover driven by early successional IAP species and abundance, and that between‐plot variation was determined by site‐specific differences, with only a weak treatment effect. Foliar spray resulted in high mortality of native saplings (52.7%) and adults (18.3%), and both herbicide applications reduced adult growth over a post‐treatment period of 12 mo.ConclusionIAP removal controlled plant invasion processes and altered community composition in the short term, regardless of removal method. Post‐treatment trajectories of seedling communities are determined by site‐specific differences. Chemicals can strongly increase the efficacy of IAP control, but short‐term detrimental effects on native saplings and adults may be expected. As re‐invasion by IAPs is likely, a long‐term restoration plan is required. Management strategies that aim to conserve β‐diversity should employ a landscape approach to habitat restoration to buffer against site idiosyncrasies.

Growing the urban forest: tree performance in response to biotic and abiotic land management

Forests are vital components of the urban landscape because they provide ecosystem services such as carbon sequestration, storm‐water mitigation, and air‐quality improvement. To enhance these services, cities are investing in programs to create urban forests. A major unknown, however, is whether planted trees will grow into the mature, closed‐canopied forest on which ecosystem service provision depends. We assessed the influence of biotic and abiotic land management on planted tree performance as part of urban forest restoration in New York City,U.S.A. Biotic treatments were designed to improve tree growth, with the expectation that higher tree species composition (six vs. two) and greater stand complexity (with shrubs vs. without) would facilitate tree performance. Similarly, the abiotic treatment (compost amendment vs. without) was expected to increase tree performance by improving soil conditions. Growth and survival was measured for approximately 1,300 native saplings across three growing seasons. The biotic and abiotic treatments significantly improved tree performance, where shrub presence increased tree height for five of the six tree species, and compost increased basal area and stem volume of all species. Species‐specific responses, however, highlighted the difficulty of achieving rapid growth with limited mortality. Pioneer species had the highest growth in stem volume over 3 years (up to 3,500%), but also the highest mortality (up to 40%). Mid‐successional species had lower mortality (<16%), but also the slowest growth in volume (approximately 500% in volume). Our results suggest that there will be trade‐offs between optimizing tree growth versus survival when implementing urban tree planting initiatives.

The exotic shrub Rosa rubiginosa as a nurse plant. Implications for the restoration of disturbed temperate forests in Patagonia, Argentina

Facilitation of forest native species under exotic nurse plants may differ between climatic regions and microsites. Recruitment of other exotic species should be taken into account when areas invaded by exotic shrubs are considered for forest restoration. Natural regeneration of native and exotic species and survival of planted native saplings under the deciduous exotic Rosa rubiginosa (shrub microsite=SM) and in open microsites (OM) were studied in preexisting shrublands of mesic and wet regions in North Patagonia. Light levels, soil chemical composition and seasonal variation of soil moisture were analyzed in SM and OM and the content of N and C was compared between mature and senescent R. rubiginosa leaves. In the SM, native species received less light and soils had higher C:N rate and moisture in spring than in the OM. R. rubiginosa reabsorbs this nutrient before leaves fall. Natural native forest species recruitment occurred only in the SM. In shrublands of the mesic region native species richness and abundance increased under bigger nurse plants. In the wet region, where herbivory was higher, moderate climatic conditions allowed greater species richness and abundance than in the mesic region, independently of the nurse plant volume. The height of the exotic shrub and the protected species showed a positive and negative relationship in the mesic and wet region, respectively. Exotic species grew under 5–15% of the nurse plants (n=60). Survival of planted saplings, shoot resprouting and herbivore-related mortality were highest in the SM and in wet regions. Sapling mortality due to drying out was highest in the OM of the mesic region. It is possible for forest restoration in areas previously invaded by R. rubiginosa to achieve highly positive results in mesic regions where plants are protected from desiccation. In areas with moderate climatic conditions, facilitation against herbivores has beneficial initial effects, but as the nurse plant competes with taller native individuals, forest restoration would depend on effective control of the nurse plant biomass. In both areas other exotic species would be well represented in the long term.

Rehabilitation of abandoned coconut plantations at D'Arros Island, Republic of Seychelles

Abandoned coconut plantations occur on tropical islands worldwide. Despite their adverse effect on local biodiversity, there is a paucity of information concerning rehabilitation methods and their respective outcomes. Previous accounts of coconut forest rehabilitation programs exclusively advocate clearcutting followed by planting of native saplings. Having experienced considerable practical and ecological complications from clearcutting on D'Arros Island, Republic of Seychelles, an alternative protocol was developed in which the upper coconut canopy was temporarily preserved so that the resultant shady environment on the forest floor might accelerate natural forest succession. Activities and progress were monitored in three experimental plots and compared to previously clearcut sites. Results suggest that the proposed method allows rehabilitation of abandoned coconut forests to be achieved sooner and at a lesser cost than clearcutting.

Effects of grasses on sapling establishment and the role of transplanted saplings on the light environment of pastures: implications for tropical forest restoration

AbstractQuestionDoes the presence of grasses affect the establishment (survival and growth) of tree saplings in an abandoned tropical pasture, and what is the potential of established saplings to modify pasture microenvironmental conditions, particularly light incidence?LocationAbandoned cattle pasture, in the humid tropics of SE Mexico (18°25′–18°45′ N, 95°00′–95°18′ W).MethodsThe establishment of four native fast‐growing tree species in a tropical abandoned pasture was evaluated. Saplings of Cecropia obtusifolia, Hampea nutricia, Omphalea oleifera and Erythrina folkersii were transplanted using a split‐plot design. Plant survival and growth were evaluated over 12 mo under two experimental treatments: presence and absence of grasses. Light incidence at ground level was used to evaluate microclimate conditions under the grass matrix, compared to light incidence under saplings established in the pasture.ResultsSaplings had high survival (49–88%) regardless of the presence of grasses. In the presence of grasses, growth of surviving saplings either increased or was not impacted, and in only one out of eight comparisons did grasses negatively affect growth. The impact of saplings on light incidence in abandoned pastures depended on sapling species architecture: species with large total leaf area and canopy area ( H. nutricia and E. folkersii) significantly reduced light incidence (12–29% of total incidence), while narrow‐canopy species ( C. obtusifolia and O. oleifera) generated less intense shade (37–89% of total incidence).ConclusionsGrasses did not seem to represent a crucial limiting factor in sapling establishment of fast‐growing native species in the short term. In addition, shading by recruited saplings of some native species could be important to out‐compete grasses in the future, as well as for ‘facilitating’ regeneration of more shade‐tolerant species. Transplantation of fast‐growing native saplings into abandoned pastures, even without manipulation of the grasses, could be a useful practice for landscape‐scale restoration programmes in tropical areas. Evaluation of the longer‐term consequences (beyond the 1‐yr span of this study) warrants further research.

Subtropical dry forest regeneration in grass-invaded areas of Puerto Rico: Understanding why Leucaena leucocephala dominates and native species fail

Throughout the tropics, non-native grasses invade, dominate, and persist in areas where subtropical and tropical dry forests have been highly degraded. In Central America and the Caribbean Islands, forests that regenerate in grass-invaded areas are generally composed of one to a few tree species, usually of the Fabaceae family and often non-native. We investigated the ecological factors that drive these successional patterns in southwestern Puerto Rico, where African grasses dominate extensive areas that are maintained by fires. The non-native legume tree Leucaena leucocephala commonly establishes in these areas and forms persistent, mono-dominant stands. We planted 455 saplings of 13 native tree species and Leucaena in native forest understory and in grass-invaded areas that were either subjected to or protected from prescribed fires 4months later. We measured growth and survival to test the following hypotheses: (1) saplings of native species are suppressed in grass-invaded areas compared to the forest understory, (2) Leucaena saplings outperform native species in grass-invaded areas, but not in the forest understory, and (3) Leucaena saplings are less susceptible to wildfires than native species. After 20months, 50%, 40%, and 3% of native saplings survived in the forest, unburned-grass, and burned-grass treatments, respectively. Over the same period, 90%, 80%, and 25% of Leucaena survived in the same treatments. The fires immediately killed 65% of native saplings and 50% of Leucaena saplings. The majority of unburned native saplings died during a seasonal drought, when high irradiance and reduced soil organic matter content likely led to higher mortality in grass-invaded areas than in forest understory. Native species’ growth was low in all treatments, yet diameter growth was slightly higher in the unburned grass than the forest understory. Leucaena saplings grew faster than the native saplings in all three treatments, especially in the unburned grass. Slow growth and high mortality of native saplings in grass-invaded areas contribute to the dominance of Leucaena in forests that regenerate on these sites and suggest that Leucaena may play a beneficial role in dry forest restoration in the Caribbean.

Response to dehydration and irrigation in invasive and native saplings: osmotic adjustment versus leaf shedding

To clarify the mechanism underlying successful invasion by tree species into xeric sites on Japan's Bonin Islands, we compared the water use of an alien species, Psidium cattleianum, which is rapidly expanding on ridge sites with shallow soil, with that of a native species, Trema orientalis. We hypothesized that there is a trade-off between leaf shedding with low cavitation resistance (frequent xylem cavitation plus refilling ability) and leaf osmotic adjustment with high cavitation resistance (cessation of xylem cavitation plus canopy leaf retention), indicating contrasting strategies for drought tolerance and water use in semi-arid regions. We examined leaf turnover, leaf gas exchange, leaf water potential and water distribution in stem xylem conduits using cryo-scanning electron microscopy for the saplings of both species under three cycles of artificial drought and sudden pulse irrigation. Invasive P. cattleianum saplings were highly resistant to cavitation in stem xylem conduits, retained their leaves and exhibited effective leaf osmotic adjustment under the drought treatment. In contrast, native T. orientalis saplings exhibited xylem cavitation, conspicuous leaf shedding and less effective leaf osmotic adjustment under the drought treatment. Leaf gas exchange rate recovered more rapidly in P. cattleianum saplings than in T. orientalis saplings immediately following pulse irrigation after a period without irrigation, especially in the first drought cycle. Embolized conduits in T. orientalis were refilled by pulse irrigation, and leaf gas exchange rate recovered following refilling. The two tree species showed contrasting strategies for drought tolerance and water use along a trade-off axis. Cavitation avoidance and effective leaf osmotic adjustment in P. cattleianum saplings under drought conditions partially support their survival at the xeric ridge sites on the Bonin Islands. Our results help to explain the success of P. cattleianum in its invasion of a sub-arid environment.

Comparisons of recruitment, survival, and growth in invasive and native saplings on a volcano

We monitored the recruitment, survival, and growth of tree saplings on invasive (Larix kaempferi) versus native species (Betula and Populus) using 16 20 m × 20 m plots established along elevation gradient on the volcano Mount Koma, Japan, for 7 years because the sapling behaviors should determine forest structures. The crowding of overstory consists mostly of Larix decreased with increasing elevation. Larix recruits were conspicuous, particularly at middle elevation where overstory crowding was intermediate, while Betula recruits were least. Larix overstory crowding inhibited the recruitment of all the taxa, although intermediate crowding promoted the recruitment of Larix. The restriction of sapling emergence was conspicuous at lower elevation where the overstory crowding was highest, probably because of shading, and/or competition with overstory trees. Sapling recruitment for all taxa was restricted at higher elevation, due to high stresses derived from direct solar radiation and strong wind without overstory. The survival of saplings was 96% for Larix and Betula, while it was ca. 50% for Populus. Larix overstory decreased the survival and growth of all the taxa, except Larix survival and Betula growth. The results implied that Larix could establish by high survival once the recruits succeeded everywhere and native sapling regeneration was restricted by Larix overstory. Strong recruitment, survival, and growth of Larix, together with resistance to overstory crowding, enables it to dominate and persist in such disturbed areas regardless of the canopy closure.

InvasiveAcer platanoidesinhibits native sapling growth in forest understorey communities

SummaryOver three growing seasons, we tested how an invasive tree species (Acer platanoides) affected native plant growth in understorey communities of a suburban forest in central New Jersey, USA. We planted similar aged and sized saplings (≥ 0.25 m tall) into experimental plots identified with one of three treatments (0%, 25% and 50% of total stems are invasive species) and hypothesized native species would grow better in communities lacking invasive plants.There was a plant survival rate of 90% for the duration of the experiment, but in treatments where natives competed withA. platanoides, growth of native species was significantly less than in the purely native stand. In 2006, the mean height ofA. rubrumwas 110 cm (±4 SE) in communities with the highest proportion ofA. platanoides, while it was 149 cm (±7 SE) in the 0% invasive communities. Conversely,A. platanoidesgrew similarly in treatments where it comprised two different proportions and beneath both canopy types (i.e. invasive and native).Native saplings were 28% shorter beneath an invasive canopy (i.e.A. platanoides), compared with a native canopy. A striking interaction existed between community treatment and canopy type, as the invasive canopy had such a strong negative effect on native growth that the presence of invasive saplings was irrelevant. However, beneath a native canopy, the absence of invasive saplings significantly increased growth of native saplings. As the extent and rate of invasive proliferation often makes complete removal unrealistic, this study supports episodic removal (every 2–3 years) of this invasive sapling.Synthesis. This experiment showed that native sapling growth was inhibited (i) when growing beneath an invasive canopy and (ii) when competing withA. platanoidesin forest understorey communities. It appears canopy type is more important, because the negative effects from an invasive canopy were strong enough that the co‐occurrence of invasive saplings had no impact on native growth. The capability ofA. platanoidesto inhibit native saplings through understorey competition and overstorey canopy effects, while not affecting conspecifics, may contribute to its success as an invader of North American forests.

Early development of three planted indigenous tree species and natural understorey vegetation in artificial gaps in an Acacia mangium stand on an Imperata cylindrica grassland site in South Kalimantan, Indonesia

Early performance of two dipterocarp species Anisoptera marginata and Shorea parvifolia, and a long-living pioneer species Peronema canescens (Verbenaceae) planted in artificial gaps (size 260 m2) and surrounding untreated stands was studied in a fast-growing plantation of Acacia mangium on an Imperata cylindrica grassland site in South Kalimantan, Indonesia. Forty seedlings of each species were planted at one-meter intervals in lines across each of the five gaps, starting and ending under closed stand. Survival, height and diameter (d0.05) increments were measured, and the effect of gap opening on the composition and abundance of understorey vegetation (grass, shrub and native tree seedlings and saplings) was studied. 19 months after planting, average survival rates were 97% for A. marginata, 94% for P. canescens and 71% for S. parvifolia, with no statistical differences between gap and closed stand. Substantial mortality and damage of dipterocarps were caused by wild boars; minor damage by dieback (for S. parvifolia) and insect pests (for A. marginata). Early growth was clearly influenced by distance from gap centre and light conditions; the growth of seedlings was greater the nearer the seedlings were situated to centre and the higher the level of daily photosynthetic photon flux density (PPFD) was. Gap opening increased the growth of shrub species Chromolaena odorata, but not that of Imperata grass. It also increased the density and height growth of saplings of native pioneer and secondary tree species. Seedling density increased both in closed stand and actual gaps, but was higher inside gaps.

DISTRIBUTION OF THE NON-NATIVE SHRUB LONICERA MAACKII IN KRAMER WOODS, OHIO

This study examined the distribution of Lonicera maackii (Amur honey-suckle) in a 5.2-ha old-regrowth deciduous forest in southwestern Ohio, and focused on its associations with: (1) forest-edge and internal-forest conditions; and (2) composition and structure of the native flora. Fine-scale vegetation patterns were measured in 60 nested plots and mapped with a geographic information system. L. maackii accounted for 24% of the relative importance of understory trees and shrubs based on its density (3361/ha), frequency (95%), and basal area (1.89m2/ha). Within-patch densities correlated significantly with edge attributes, but stem-basal areas were best explained by a covariate model that coupled edge conditions with internal topographic settings. Detrended correspondence analysis identified spatial patterns of community diversity in the understory native flora, and honeysuckle abundances were highest in small discontinuous community patches. Species richness and densities of native shrubs (Lindera benzoin and Viburnum prunifolium) and Acer saccharum saplings were lower when honeysuckle abundances were >3000/ha and/or basal areas were >4 m2/ha. These findings identified the importance of forest-edge and internal-forest conditions on spatial patterns of invasion by L. maackii and support management plans that target locations within a forest patch and forest-patch locations of highest potential impact. [Key words: conservation, eastern deciduous forest, exotic plants, forest ecology, landscape ecology.]

Foliar nutrient concentrations of small Chamaecyparis in Taiwan

Seedlings ofChamaecyparis lawsoniana, C. formosensis andC. taiwanensis were grown in a forest nursery in Taiwan. Native saplings of the latter two species were sampled in a clearcut and in the forest understory. Foliar nutrient concentrations were mostly in the mid-range of values for other conifers. However, Ca (.59–1.5%) and Cu (7–20 ppm) were almost always high. Concentrations of N, P, and K in field saplings in Taiwan were low enough (.7–1.5%, .07–.15%, .47–.60%, respectively) to indicate that these elements are probably limiting growth.