Seedling Plots Research Articles

Analysis of Vegetation and Plant Diversity in High Conservation Value Areas in Oil Palm Plantations

The expansion of oil palm plantations is often rumored to impact the destruction of forests and other ecosystems with high conservation value (HCV). This study aimed to analyze the vegetation and plant diversity in the HCV area of oil palm plantations. The research was conducted on an oil palm plantation in Seruyan District, Central Kalimantan Province, Indonesia with an HCV area of 5379 ha. The research was carried out using the grid transect method on various types of vegetation, divided into four plots: seedlings, saplings, poles and trees. Parameters observed included the number of species, the number of individuals and the level of plant diversity. The results showed that the research location had good vegetation and plant diversity in the HCV area. There were 25 plant species from 17 families with a total of 355 plants. The number of species found in the seedling plots was 11 species (6 families) with a total of 38 plants; in the sapling plots was 16 species (12 families) with a total of 159 plants; in the pole plots was 14 species (11 families) with a total of 43 plants, and in the tree plots was 13 species (10 families) 115 plants. There was variation in the number of species and families in each plot. The overall plant diversity index was low. The diversity index of plants in the plots of seedlings, saplings, poles and trees (and the average) was in the low category.

Long-term seedling and small sapling census data from the Barro Colorado Island 50 ha Forest Dynamics Plot, Panama.

Tropical forests are well known for their high woody plant diversity. Processes occurring at early life stages are thought to play a critical role in maintaining this high diversity and shaping the composition of tropical tree communities. To evaluate hypothesized mechanisms promoting tropical tree species coexistence and influencing composition, we initiated a census of woody seedlings and small saplings in the permanent 50 ha Forest Dynamics Plot (FDP) on Barro Colorado Island (BCI), Panama. Situated in old-growth, lowland tropical moist forest, the BCI FDP was originally established in 1980 to monitor trees and shrubs ≥1 cm diameter at 1.3 m above ground (dbh) at ca. 5-year intervals. However, critical data on the dynamics occurring at earlier life stages were initially lacking. Therefore, in 2001 we established a 1-m2 seedling plot in the center of every 5 × 5 m section of the BCI FDP. All freestanding woody individuals ≥20 cm tall and <1 cm dbh (hereafter referred to as seedlings) were tagged, mapped, measured, and identified to species in 19,313 1-m2 seedling plots. Because seedling dynamics are rapid, we censused these seedling plots every 1-2 years. Here, we present data from the 14 censuses of these seedling plots conducted between the initial census in 2001 to the most recent census, in 2018. This data set includes nearly 1 M observations of ~185,000 individuals of >400 tree, shrub, and liana species. These data will permit spatially-explicit analyses of seedling distributions, recruitment, growth, and survival for hundreds of woody plant species. In addition, the data presented here can be linked to openly-available, long-term data on the dynamics of trees and shrubs ≥1 cm dbh in the BCI FDP, as well as existing data sets from the site on climate, canopy structure, phylogenetic relatedness, functional traits, soil nutrients, and topography. This data set can be freely used for non-commercial purposes; we request that users of these data cite this data paper in all publications resulting from the use of this data set.

Assessing the impact of abiotic and biotic factors on seedling survival in an African montane forest

Tree seedling dynamics underpin subsequent forest structure and diversity as different species/guilds respond variously to abiotic and biotic stresses. Thus, understanding differential seedling responses to stresses helps us to predict forest trajectories. Because forests vary in both environment and species composition, generalisations across tropical forests are difficult. Afromontane forests are important carbon stores, harbour high diversity and provide critical ecosystem services, yet they are vulnerable to climate change. Here, we investigate the importance of key abiotic and biotic factors on survival of seedling guilds along spatial and temporal scales in a montane forest in south-eastern Nigeria. We use data from 318 seedling plots censused every 3 months from 2017 to 2020 to identify seven key abiotic and four biotic factors influencing seedling survival. We used the Kaplan–Meier method to estimate the persistence time of 1,145 seedlings at community and guild levels. At the community level, newly recruited seedlings had a median survival time of 15 months and about 37% of the seedlings sampled where still alive after 24 months. Understory tree species survived significantly longer than the other growth form guilds and seedling survival did not differ across shade tolerance guilds. Conspecific adult density and steeper, more north facing slopes had a negative effect on tree seedlings survival. In addition, tree seedlings that recruited in October (end of wet season/beginning of dry) had lower survival probabilities compared to those that recruited in the other months. Except for initial height, seedling survival in lianas was not impacted by any of the abiotic and biotic variables tested. Our results suggest that under the current environment forest structure and diversity is changing, most noticeably lianas are increasing in abundance relative to trees.

Warming shifts soil microbial communities and tropical tree seedling mortality.

Plant-soil feedback (PSF), regulated by both mycorrhizae and soil-borne pathogens, is a primary mechanism maintaining high tree species diversity in the tropics. But how warming actually affects PSF is not well understood. We conducted a field warming experiment to test PSF on seedling mortality of two tree species: a rhizobia-associated tree (Ormosia semicastrata, Fabaceae) suffering from host-specific soil-borne pathogens and an ectomycorrhizal fungi-associated tree (Cyclobalanopsis patelliormis, Fagaceae) with low susceptibility to soil-borne pathogens. Soil fungi from the warming versus control seedling plots were identified by molecular sequencing. Results showed that the elevated temperature lowered seedling mortality of O. semicastrata, but had no effect on C. patelliormis seedlings. This indicates that warming weakened the negative PSF on O. semicastrata, presumably due to the observed decrease of the relative abundance of plant-pathogenic fungi and increase of ectomycorrhizal fungi but did not affect the PSF on C. patelliormis. The differential warming effects on seedling mortality of species with different microbial associations affords an example showcasing how the change in soil-borne microbes in response to global warming would, in turn, through PSF, alter tropical tree species composition and diversity. This study helps shed mechanistic light on the debate of biodiversity change as driven by climate change.

ASSESMENT OF ENVIRONMENTAL QUALITY MANGROVE AREAS FOR IMPROVING COASTAL MANAGEMENT IN PAHAWANG ISLAND

Pahawang Island has natural and manmade mangrove areas. One of the locations that still has original mangroves is in the Petambun. The increase in the number of tourists to this area has made the mangrove area decrease. Thus, it is necessary to discuss environmental quality in the aim of successful management. Coastal management takes into ecological, socio-cultural and economic factors. The purpose of this study was to determine the ecological factors of mangroves based on the volume and importance value of mangroves. The general purpose of the research to find out the strategy for improving the management of mangrove areas on Pahawang Island. The results showed that in the Petambun location, Pahawang Island, there was Rizophora mucronata with an important value of 106.61% in the seedling plots and 94.88% importance in the tall tree plots. The highest volume of mangroves in Petambun Pahawang Island was Rizophora apiculata at 54% with a volume of 2,929.51 m3/ha. Based on the SWOT analysis, it is explained that in the management of mangrove areas, the most important index is the participation of local communities and governments in the classification of use areas so that their function is not converted into tourist areas.&#x0D; Keywords: coastal, mangroves, management, Pahawang Island, quality area

IDENTIFIKASI JENIS MANGROVE PADA KAWASAN RESTORASI EKOSISTEM MANGROVE DI DESA KEUDE PANGA KECAMATAN PANGA KABUPATEN ACEH JAYA

This study aimed to identified mangrove species, calculated the total number and composition of mangroves, and the structure of zonation mangroves at the mangrove relocation area in Keude Panga Village, Panga District, Aceh Jaya Regency. The study was carried out on April 2021, for one month with two replications. The research method was the survey method, namely directed observation to research location. A sampling of mangroves used the quadratic transect method, which was divided into 3 transect points with the categories of tree plots measuring 10 m x 10 m, sapling plots with 5 m x 5 m, and the seedling plots measuring 1 m x 1 m. Data analyzed of the total number and composition of mangroves used Microsoft Excel 2010 and zonation of mangrove analysis was carried out descriptively. The results showed on the research at both stations founded 3 species of true mangrove and 1 species of scrub respectively, namely Rhizhopora mucronata (19% sapling level), Rhizhopora apiculata (34% sapling level), Nypa fruticans (47% tree level), Acrostichum aureum (or 100% shrub category) and Rhizhopora mucronata (23 individuals or 37% sampling level), Rhizhopora apiculata (15 individuals 20% sapling level), Nypa fruticans (36 individuals or 49% tree level), Acrostichum aureum (100% shrub category). Structure zonation of mangrove vegetation is composed of 3 species of mangroves, namely Rhizhopora mucronata which was located closest to the sea, Rhizhopora apiculata was in the middle of the mangrove ecosystem, and Nypa fruticans was a pioneer mangrove located close to the mainland.

Site‐specific impacts of a major hurricane on alpha and beta diversity in tropical forest seedling communities

AbstractLarge scale disturbances are known to impact the alpha and beta diversity of communities. However, whether these disturbances increase or decrease diversity is often debated. The goal of this study was to quantify how the diversity of the seedling community was impacted within and across elevation in the El Yunque forest of Puerto Rico following a major hurricane. We tested two alternative hypotheses, that hurricanes are relatively more homogenizing or non‐homogenizing forces, by quantifying changes in alpha and beta diversity of the seedling community post‐hurricane. This approach highlights whether ecological mechanisms associated with community homogenization (species‐specific survival, successional processes, and reduced environmental heterogeneity) or non‐homogenization (resource release, increased environmental heterogeneity, and stochastic processes) structure the seedling community post‐hurricane. We compared species richness, Fisher’s α, Simpson’s evenness, and multiple aspects of beta diversity within and among 25 seedling plots at 300, 400, and 500 m in elevation pre‐ and post‐hurricane. We found that species richness, diversity, and evenness were higher post‐hurricane, but abundance decreased 19%. Increases in alpha diversity suggest that hurricanes are non‐homogenizing forces potentially linked with increases in light levels promoting colonization of early‐successional species and resource release for other light‐demanding species. The beta diversity results varied in their support for hurricanes as homogenizing depending upon the spatial scale of the analysis, potentially due to a combination of mechanisms including species‐specific survival and site‐specific differences. To fully grasp how the seedling community responds and recovers from disturbance, additional long‐term monitoring will be needed to allow insight into the future of species richness, abundance, and spatial and temporal changes in community composition.

Individual-level leaf trait variation and correlation across biological and spatial scales.

Even with increasing interest in the ecological importance of intraspecific trait variation (ITV) for better understanding ecological processes, few studies have quantified ITV in seedlings and assessed constraints imposed by trade‐offs and correlations among individual‐level leaf traits. Estimating the amount and role of ITV in seedlings is important to understand tree recruitment and long‐term forest dynamics. We measured ten different size, economics, and whole leaf traits (lamina and petiole) for more than 2,800 seedlings (height ≥ 10 cm and diameter at breast height < 1 cm) in 283 seedling plots and then quantified the amount of ITV and trait correlations across two biological (intraspecific and interspecific) and spatial (within and among plots) scales. Finally, we explored the effects of trait variance and sample size on the strength of trait correlations. We found about 40% (6%–63%) variation in leaf‐level traits was explained by ITV across all traits. Lamina and petiole traits were correlated across biological and spatial scales, whereas leaf size traits (e.g., lamina area) were weakly correlated with economics traits (e.g., specific lamina area); lamina mass ratio was strongly related to the petiole length. Trait correlations varied among species, plots, and different scales but there was no evidence that the strength of trait relationships was stronger at broader than finer biological and spatial scales. While larger trait variance increased the strength of correlations, the sample size was the most important factor that was negatively related to the strength of trait correlations. Our results showed that a large amount of trait variation was explained by ITV, which highlighted the importance of considering ITV when using trait‐based approaches in seedling ecology. In addition, sample size was an important factor that influenced the strength of trait correlations, which suggests that comparing trait correlations across studies should consider the differences in sample size.

Using associational effects of European beech on Norway spruce to mitigate damage by a forest regeneration pest, the pine weevil Hylobius abietis

Forest regeneration can be compromised by insect damage to newly-planted conifer seedlings, with the pine weevil, Hylobius abietis, being the most economically important pest in Europe. Seedling protection strategies include physical barriers, silvicultural measures and insecticides, while the potential benefits of Associational Effects (AE) have been little explored. Associational Resistance (AR) or Susceptibility (AS) arise when neighbouring plants decrease or increase, respectively, the likelihood and extent of attack on a focal plant. We investigated the potential of European beech, Fagus sylvatica, to mediate AE for Norway spruce, Picea abies, seedlings against pine weevil damage. First, we examined the effects of neighbor identity on damage to P. abies at a small scale, using choice arenas in the lab. Then, in the field, we examined these effects at a larger scale using plots containing only Norway spruce, or both species. We found that P. abies seedlings were attacked and damaged less by weevils when beech was their close neighbor, relative to having another Norway spruce as a neighbor in the lab. Yet, no difference in damage between only spruce and mixed seedling plots was found in the field. Our results indicate that the susceptibility of P. abies to H. abietis can be influenced by neighbor identity, and effects can vary with inter-plant distance. In close proximity, the presence of the non-host F. sylvatica can alter pine weevil feeding behaviour and thus, has the potential to mediate AR. However, these associational effects appear not to provide enhanced seedling protection at a larger scale.

Light can modify density‐dependent seedling mortality in a temperate forest

AbstractQuestionsThere is growing evidence on how density‐dependent drivers of plant performance are influenced by habitat heterogeneity such as variation in understorey light availability. How these processes operate in temperate forests still remains an open question, however. We examined the interactive effects of density dependence and light availability on woody seedling mortality across multiple species, two size stages and growth forms.LocationAlluvial old‐growth temperate forest, southeastern Czech Republic.MethodsWe mapped seedlings of woody species (≥10 cm tall) and recorded their mortality over a two‐year period on 21 square seedling plots (25 m2) within one large square plot with all trees mapped (≥1 cm diameter at breast height). Seedling mortality was studied using a combined approach of generalised linear mixed models and spatial point pattern analyses.ResultsDensity‐dependent effects of tree and seedling neighbours influenced seedling mortality at different spatial scales, depending on their size class, growth form and by taxon. Conspecific inhibition raised the mortality of seedlings other than Acer campestre at low light levels, indicating that host‐specific enemies and/or intraspecific competition may be important in unfavourable habitats. While small seedlings experienced conspecific inhibition at low light levels, tall seedlings were additively affected by low‐light conditions and competition with trees. Both conspecific and heterospecific neighbours tended to affect tree seedlings at low light levels, whereas shrub seedlings experienced light‐ and density‐independent mortality. Some negative interspecific interactions indicated ongoing expansion of species like Acer campestre in currently flood‐free habitats.ConclusionsHow density‐dependent effects translate into demographic outcomes for woody seedling populations may be largely determined by variation in understorey light availability. Given that seedlings differ in size, growth form and taxa, we also demonstrate that both seedling and tree neighbours may contribute to the strength and spatial variation in density‐dependent effects at seedling neighbourhood scales.

Estimation of the potential of understorey and litter carbon on the shrub bush vegetation in Aceh Besar District

The distribution of shrub vegetation is almost evenly distributed in Aceh Besar district. The desire to see the carbon potential in this vegetation and treat it - future treatment will be carried out both reforestation and soil management to increase carbon stock for the future. Therefore, it is necessary to research and determine how much carbon potential is in scrub vegetation in the district Aceh Besar by making plots according to field conditions. Then, decided each vegetation growth on seedling plot sizes with a minimum area of 4 m2 (growth rate woody vegetation < 2 cm in diameter with a height = 1.5 m) and minimal stake plot area 25 m2 (growth rate of woody vegetation with a diameter of 2 cm to <10 cm). Each plot, both seedling and sapling plots, was repeated five times. Vegetation Shrubs <2 cm in size are dominated by Teki grass (Cyperus rotundus) and Putri Malu (Mimosa pudica). For shrub, vegetation measures 2 cm - 10 cm across dominance by Acacia mangium plants. The total amount of plant carbon biomass is 2,053,546.33 tonnes/ha, a C value of 964,990.26 tonnes/ha, and the potential for CO2 absorption at plants amounting to 3,540,455.15 tonnes/ha on shrub vegetation in the district Aceh Besar.

Plant trait differences and soil moisture jointly affect insect herbivory on seedling young leaves in a subtropical forest

Insect herbivory on seedling leaves is one of the most important factors driving seedling growth and mortality in natural forests, which sets the pivotal roles of insect herbivory in affecting natural forest regeneration and species composition. The intensity of herbivory can be influenced by multiple biotic and abiotic factors affecting leaf detection or consumption by insect herbivores. However, the relative importance of these biotic and abiotic factors in affecting insect herbivory and their interactions remain largely unknown in species-rich forests. We measured insect herbivory on seedling young leaves across 600 1 m × 1 m seedling plots in a subtropical forest. Effects of nine seedling traits, neighboring plant compositions, soil moisture, and light availability on young leaf damage by insect herbivores were assessed with generalized linear mixed-effects models. We found that seedling traits associated with plant size (young leaf area and seedling height), leaf nutrition or defense (leaf thickness, carbon content, and stem specific length) explained more of the variation in insect herbivory than the biotic and abiotic environmental factors. Young leaf coloration (delayed greening degree) exhibited contrasting effects on leaf damage at wet vs. dry sites, so did seedling trait diversity (functional dispersion, FDis). The risk of insect herbivory increased with leaf redness and decreased with seedling FDis at wet sites, while the opposite trends were observed at dry sites. Our study advances the understanding on the driving factors of insect herbivory on seedling leaves in species-rich forests and suggests that the alleviating effects of plant diversity on insect herbivory were stronger at wet conditions.

The assessment of field resistance to scab and winter resistance of columnar apple trees in the Samara Region

The research was conducted from 2006 to 2019 in the garden of Research Institute of Horticulture and Medicinal Plants Zhigulevskie Sady in the village of Malaya Tsarevshchina of Krasnoyarsk District of the Samara Region on 14 (0,432 ha), 43 (0,1 ha), 44 (0,05 ha) and 47 (6,8 ha) areas. On the 14th area, to accelerate flowering, fruiting, pollen collection and hybridization, in the springs of 2007, 2009 and 2012, parent varieties-donors of immunity were grafted to scab of domestic and foreign selection in the crown of young fruit-bearing trees of the Northern synapsis. Hybrid seeds obtained by crossing these varieties with local varieties were sown on the seedling plot (in a new plantation) and tested for scab resistance at an early age (from 2 years old). Scab-resistant hybrids were culled, and resistant hybrids were replanted in the breeding garden on the 47th area and tested for winter resistance separately after low-temperature stress in the freezer and in the field. The authors have identified columnar elites resistant to scab, which are superior in winter resistance to the local zoned coastal variety Kutuzovets, zoned variety Northern synapsis and common Antonovka. Apple trees with a columnar crown type of local selection in Research Institute of Horticulture and Medicinal Plants Zhigulevskie Sady with a high field resistance to scab, immunity, winter resistance and other varietal advantages will contribute to the improvement of orchards (amateur, farm, industrial) and import substitution of fruit products in the Samara Region of Russia.

Effects of biotic/abiotic factors on the seedling regeneration of Dacrydium pectinatum formations in tropical montane forests on Hainan Island, China

Exploring natural regeneration facilitates a better understanding of the mechanisms of community assembly and biodiversity formation. However, convincing data on tree regeneration in threatened tropical plant communities are lacking. Dacrydium pectinatum is a constructive and endangered species in tropical montane forests of Hainan Island. This study aims to identify the seedling regeneration patterns of D. pectinatum formation and their key drivers. A total of 204 seedling plots were investigated in the northwest (Bawangling, 90 plots), southwest (Jianfengling, 90 plots) and southeast (Diaoluoshan, 24 plots) of Hainan Island. We examined the variations in the seedling/adult composition, density and richness along local scales and elevation gradients and analyzed the relationships between biotic/abiotic variables and seedling regeneration. The seedling distribution pattern changed with environmental gradients, and the seedling density and richness decreased from low to high latitudes and from low to high elevations. Additionally, the adult density and total base area also showed consistent trends. At the community and species levels, the biotic neighborhood variables had a primary impact on the seedling density and richness. Multiple environmental factors (such as the canopy density, elevation, slope, soil organic matter, and soil total nitrogen) also showed significant correlations with the seedling density and richness. Our study supports conspecific negative density dependence and niche filtering as the general mechanisms of natural regeneration of D. pectinatum formations. Both biotic and abiotic factors might affect the survival and growth of seedlings, and their relative importance varies with environmental gradients and species. We conclude that enclosing forests with moderate stand densities in low-elevation areas to reduce human interference will help optimize the community structure. However, for high-elevation areas and high-density forests, appropriate thinning, manual regeneration and open gaps are needed to improve the light environment and soil nutrients, thereby promoting the natural regeneration of D. pectinatum formations.

Edge Effects on Seedling Diversity Are Mediated by Impacts of Fungi and Insects on Seedling Recruitment but Not Survival

Growing awareness of the role of enemies in plant community dynamics has led to ecologists exploring how plant-enemy interactions change in human-modified systems. Proximity to forest edges was found to weaken the role of two groups of plant enemies—insect herbivores and fungal pathogens—in increasing plant diversity during the seed-to-seedling transition. However, it is less clear whether edge effects similarly compromise the diversifying effects of fungi and insects on established seedlings. We examined this question in a human-modified wet tropical forest in the Western Ghats of southern India. Over an annual cycle of recruitment, in 730 seedling plots (1 × 1 m each) arrayed at distances 0–100 m from the forest edge across 15 locations in a 30 km2 landscape, we suppressed the activity of fungal pathogens and insect herbivores by applying fungicide and insecticide to soil, seeds, and seedlings in a subset of plots. Suppressing fungi and insects reduced diversity mainly for seedling recruits and not for seedlings that had already established. However, pesticide effects were only apparent at 90–100 m from forest edges. Specifically, in the interior sites, fungi and insect activity increased recruit diversity, which helped maintain local seedling diversity even though diversity of established seedlings declined with annual mortality. By comparison, canopy openness affected neither the diversity of survivors from the initial seedling cohort nor total seedling diversity after an annual cycle of recruitment. Our results indicate that insects and fungi promote diversity more prominently during early seedling establishment rather than through impacts on post-establishment seedling survival. Thus, edge effects can weaken the diversifying effects of plant-insect and plant-fungal interactions during recruitment and thereby modify the seedling template available for the future tree community in human-modified forests.

Spatio-temporal dynamics of seedling communities are determined by seed input and habitat filtering in a subtropical montane forest

Spatial and temporal variation in species abundances and distributions of the seedling community, which plays a pivotal role in maintaining species diversity, can help predict future changes in forest communities. We monitored the dynamics of 12,830 seedlings within 405 1-m2 seedling plots in the Badagongshan (BDGS) 25-ha forest dynamic plot over a 6-year period (2012–2017). We presented changes in the relative abundance for 15 dominant seedling species during the last six years, assessed temporal changes in species richness, species turnover, seedling density, species reordering (mean rank shift of the relative abundance; MRS) and community similarity within three topographically defined habitats (ridge, slope and valley), and explored the mechanisms underlying dynamics of seedling communities. Furthermore, we explored differences in species’ ecological indicator values (EIVs) and functional groups for species gained and lost during the study period. Across three habitat types, there were enormous reordering of the 15 dominant seedling species; a few mast-seedling events were clearly identified. Both species richness and seedling density continually declined over the entire census year, except for an increase of species richness during 2012–2013. Species turnover fluctuated temporally in three habitat types; overall, species emigration rate was higher than species immigration rate in three habitats. Valleys with lower soil C:N ratio, light availability and VDCN (vertical distance above the channel network), but higher soil pH and TWI (topographic wetness index), had lower species richness and stem density, and higher species turnover and species reordering than slopes and ridges. At the community-wide scale, significant directional changes in species composition occurred on ridges and slopes. Newly colonizing species were typically more shade- tolerant, water- and temperature- demanding shrub species and grown on soil with low pH but high fertility. In the BDGS plot, species richness and seedling density fluctuated in the first two years and then decreased over time, which reflects that both habitat filtering and seed input regulated temporal dynamics of species composition, but the relative importance varied among studied years. In this subtropical forest, species composition showed obvious directional changes. Shrub species increased more than species of other strata in ridge and slope areas. It is worth noting that an increased dominance of species that are more water-demanding could increase the risk of mortality under global climate change (e.g. drought).

REGENERASI ALAMI JENIS NON DIPTEROCARPACEAE DI HUTAN PENDIDIKAN FAHUTAN UNMUL (HPFU) SAMARINDA

This study aims to determine the natural condition of Non Dipterocarpaceae regeneration. The object of this research are sapling and seedling in secondary forests of HPFU by making 5 transects with length 200 meters where its laid 5 x 5 meters sapling plot and 2 x 2 meter seedling plot systematically each on the right and left side. The transects was made purposively by considering areas that were still natural or had not been planted before. The results showed that regeneration was dominated by shrub habitus at both growth level, Fordia splendidissima (Miq.) Buijsen dominating the sapling level and Psychotria viridiflora Reinw. Ex Blume dominating the seedling level. However, the number of individuals at sapling stage is more bigger than the number of seedling. The Fabaceae and Rubiaceae family are most common in this location. The diversity index value is classified as high with a composition that is almost even but still dominated by several species. By comparing the data before burning from Riswan in 1987 with the current research in the same location, it can be concluded that the regeneration of Non Dipterocarpaceae in HPFU area has decreased and it represent the species degradation after forest fires.

REGENERASI ALAMI JENIS NON DIPTEROCARPACEAE DI HUTAN PENDIDIKAN FAHUTAN UNMUL (HPFU) SAMARINDA

This study aims to determine the natural condition of Non Dipterocarpaceae regeneration. The object of this research are sapling and seedling in secondary forests of HPFU by making 5 transects with length 200 meters where its laid 5 x 5 meters sapling plot and 2 x 2 meter seedling plot systematically each on the right and left side. The transects was made purposively by considering areas that were still natural or had not been planted before. The results showed that regeneration was dominated by shrub habitus at both growth level, Fordia splendidissima (Miq.) Buijsen dominating the sapling level and Psychotria viridiflora Reinw. Ex Blume dominating the seedling level. However, the number of individuals at sapling stage is more bigger than the number of seedling. The Fabaceae and Rubiaceae family are most common in this location. The diversity index value is classified as high with a composition that is almost even but still dominated by several species. By comparing the data before burning from Riswan in 1987 with the current research in the same location, it can be concluded that the regeneration of Non Dipterocarpaceae in HPFU area has decreased and it represent the species degradation after forest fires.

Assessing spectral measures of post-harvest forest recovery with field plot data

Information regarding the nature and rate of forest recovery is required to inform forest management, monitoring, and reporting activities. Delayed establishment or return of forests has implications to harvest rotations and carbon uptake, among others, creating a need for spatially-explicit, large-area, characterizations of forest recovery. Landsat time series (LTS) has been demonstrated as a means to quantitatively relate forest recovery, noting that there are gaps in our understanding of the linkage between spectral measures of forest recovery and manifestations of forest structure and composition. Field plots provide a means to better understand the linkage between forest characteristics and spectral recovery indices. As such, from a large set of existing field plots, we considered the conditions present for the year in which the co-located pixel was considered spectrally recovered using the Years to Recovery (Y2R) metric. Y2R is a long-term metric of spectral recovery that indicates the number of years required for a pixel to return to 80% of its pre-disturbance Normalized Burn Ratio value. Absolute and relative metrics of recovery at 5 years post-disturbance were also considered. We used these three spectral recovery metrics to predict the stand development class assigned by the field crew for 284 seedling plots with an overall accuracy of 73.59%, with advanced seedling stands more accurately discriminated (omission error, OE = 15.74%) than young seedling stands (OE = 49.84%). We then used field-measured attributes (e.g. height, stem density, dominant species) from the seedling plots to classify the plots into three spectral recovery groups, which were defined using the Y2R metric: spectral recovery in (1) 1–5 years, (2) 6–10 years, or (3) 11–15 years. Overall accuracy for spectral recovery groups was 61.06%. Recovery groups 1 and 3 were discriminated with greater accuracy (producer’s and user’s accuracies > 66%) than recovery group 2 (< 50%). The top field-measured predictors of spectral recovery were mean height, dominant species, and percentage of stems in the plot that were deciduous. Variability in stand establishment and condition make it challenging to accurately discriminate among recovery rates within 10 years post-harvest. Our results indicate that the long-term metric Y2R relates to forest structure and composition attributes measured in the field and that spectral development post-disturbance corresponds with expectations of structural development, particularly height, for different species, site types, and deciduous abundance. These results confirm the utility of spectral recovery measures derived from LTS data to augment landscape-level assessments of post-disturbance recovery.

Experiences in Transplanting Wood Ants into Plantations for Integrated Pest Management

Ants can function efficiently as biocontrol agents in open field horticulture. Temperate wood ants can control forest pests, including species damaging forest regeneration plots and fruit plantations. Thus, they possess potential as biocontrol agents in open field horticulture, if they can persist in these systems. Here we present observationson activity and survival of wood ants transplanted from forests into different types of plantations. Mound fragments were transplanted into a conifer seedling plot, an organic and a conventional Christmas tree plantation, and into an organic apple plantation. Colonies survived at least one year in all types of plantations. In some cases, however, ants moved to new locations or migrated between mound fragments, leaving some inactive. Our compiled experiences suggest that this can be prevented by providing a minimum mound size, keeping a minimum spacing between mounds and incorporation of sand and scent marked wood pieces from donor colonies to imitate naturally occurring nests. We also observed that the ants preyed upon and significantly reduced the number of winter moth larvae (Operophtera brumata – a pest in apple and other fruit orchards) in two of four apple varieties. In conclusion, wood ants were tolerant to highly diferente habitat settings and will likely persist in most types of perennial horticultural systems, if managed properly. As they prey on winter moths and multiple other pest species, they are a potential new biocontrol agent for open agricultural systems.