Number Of Sample Plots Research Articles

Comparative Verification of Leaf Area Index Products for Different Grassland Types in Inner Mongolia, China

Leaf area index (LAI) is a key indicator of vegetation structure and function, and its products have a wide range of applications in vegetation condition assessment and usually act as important input parameters for ecosystem modeling. Grassland plays an important role in regional climate change and the global carbon cycle and numerous studies have focused on the product-based analysis of grassland vegetation changes. However, the performance of various LAI products and their discrepancies across different grassland types in drylands remain unclear. Therefore, it is critical to assess these products prior to application. We evaluated the accuracy of four commonly used LAI products (GEOV2, GLASS, GLOBMAP, and MODIS) using LAI reference maps based on both bridging and cross-validation approaches. Under different grassland types, the GLASS LAI performed better in meadow steppe (R2 = 0.26, RMSE = 0.41 m2/m2) and typical steppe (R2 = 0.32, RMSE = 0.38 m2/m2); the GEOV2 LAI performed better in desert steppe (R2 = 0.39, RMSE = 0.30 m2/m2). When we assessed their spatial and temporal discrepancies during the period from 2010 to 2019, the four LAI products overall showed a high spatial and temporal consistency across the region. Compared with GLASS LAI, the most consistent to least consistent correlations can be ordered by GEOV2 LAI (R2 = 0.94), MODIS LAI (R2 = 0.92), and GLOBMAP LAI (R2 = 0.87). The largest differences in LAI throughout the year occurred in July for all grassland types. Limited by the location and number of sample plots, we mainly focused on spatial and temporal variations. The spatial heterogeneity of land surface is pervasive, especially in vast grassland areas with rich grassland types, and the results of this study can provide a basis for the application of the product in different grassland types. Furthermore, it is essential to develop highly accurate and reliable satellite-based LAI products focused on grassland from the regional to the global scale according to these popular approaches, which is the next step in our work plan.

Vegetation Structure, Biomass, and Carbon Stock of Urban Forest of Bongohulawa National Wirakarya Campground in Gorontalo Regency - Gorontalo Province

An urban forest is one type of Urban Green Open Space (RTHKP) that reflects the character of nature and/or local culture with ecological, historical, and panoramic values that are unique to the level of technology application. The urban forest of the National Wirakarya Campsite is quite attractive, has a lovely view, is close to the road, and is easily accessible by the residents. This study aims to determine the structure of vegetation, biomass, and carbon values stored in the urban forest of the National Wirakarya Campsite, Bongohulawa, Gorontalo Regency, Gorontalo Province. The method used is a survey method with a quantitative descriptive research design. The sampling method used is a purposive sampling model based on land cover in the urban forests. For the measurement of the vegetation structure, the sampling of vegetation in the observation plots is carried out by using the number of sample plots that are placed regularly by calculating the Relative Density (RD), Relative Frequency (RF), and Relative Dominance (RDo), then the data obtained are tabulated to provide IVI. To measure the carbon stocks on the surface (stems), a non-destructive sampling method is used with an Allometric equation based on the plant species. The results showed, there were 13 families, 20 species, and 824 individuals. The vegetation structure in the urban forest of Bongohulawa National Wirakarya Campsite (PWN) has an IVI above 15 percent on average. The sawlog level is dominated by the Gmelina arborea (beechwood) species with an IVI of 98.36 percent, the pole level is dominated by the Swietenia mahagagoni (mahogany) with an IVI of 165.37 percent, the sapling level was dominated by Swietenia mahagoni with an IVI of 160.99 percent and the seedling level was dominated by Lantana camara (tembelekan) with an IVI of 32.25 percent. The content of biomass stored in the standing trees is 1,190.45 tons/ha, with the largest amount of biomass is at the sawlog level of 1,135.43 tons/year or 95.43 percent, the total biomass at the pole level is 45.10 tons/year or 3.79 percent and the amount of long-term biomass is 9.32 tons/year or 0.78 percent. The carbon stock stored (C-Stock) is 559.37 tons/ha and can absorb CO2 (CO2eq) of 2,052.88 tons/ha and provides converted O2 of 1,498.60 tons/ha.

Impact of an Extremely Dry Period on Tree Defoliation and Tree Mortality in Serbia.

This paper presents research results on forest decline in Serbia. The results were obtained through monitoring defoliation of 34 tree species at 130 sample plots during the period from 2004 to 2018. This research aimed to determine whether the occurrence of defoliation and tree mortality were caused by drought. Defoliation was assessed in 5% steps according to the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) methodology. All the trees recorded as dead were singled out, and annual mortality rates were calculated. To determine changes in air temperature and precipitation regimes during the study period, we processed and analysed climatic data related to air temperature and precipitation throughout the year and in the growing season at 28 main weather stations in Serbia. Tree mortality patterns were established by classifying trees into three groups. The first group of trees exhibited a gradual increase in defoliation during the last few years of monitoring, with dying as the final outcome. The second group was characterised by sudden death of trees. The third group of trees reached a higher degree of defoliation immediately after the first monitoring year, and the trees died after several years. Tree mortality rates were compared between years using the Standardised Precipitation Evaporation Index (SPI) and the Standardised Precipitation Evapotranspiration Index (SPEI), the most common methods used to monitor drought. The most intensive forest decline was recorded during the period from 2013 to 2016, when the largest percentage of the total number of all trees died. According to the annual mortality rates calculated for the three observation periods (2004–2008, 2009–2013, and 2014–2018) the highest forest decline rate was recorded in the period from 2014 to 2018, with no statistically significant difference between broadleaved and coniferous tree species. As the sample of coniferous species was small, the number of sample plots should be increased in order to achieve better systematic forest condition monitoring in Serbia. The analysis of the relationship between defoliation and climatic parameters proved the correlation between them. It was noted that the forest decline in Serbia was preceded by an extremely dry period with high temperatures from 2011 to 2013, supporting the hypothesis that it was caused by drought. We therefore conclude that these unfavourable climatic conditions had serious and long-term consequences on forest ecosystems in Serbia.

Aboveground Blue Carbon Stock Assessment of Bakhawan Eco-Park Mangrove Plantation in New Buswang, Kalibo, Aklan, the Philippines

The purpose of this study was to determine the aboveground biomass density, blue carbon stock, and monetary value of the mangroves at Bakhawan Eco-Park Mangrove Plantation in New Buswang, Kalibo, Aklan. There were 21, 45 × 45-meter sampled plots established, equivalent to 5% sampling intensity of the plantation’s total area. The number of sample plots was distributed in proportion to the area of the plantation in the specific year it was established. The quadrant and random sampling methods were used. All trees in a quadrant were identified, and the biomass density was calculated using the wood density of various mangrove species. Carbon stock was calculated by multiplying the biomass density by 0.46 or 0.5. The monetary value of C was calculated using the benefits transfer method at $5/ton. The results showed that the plantation established in 1990 had the highest biomass density (Mg/ha) and carbon stock (Mg/ha) with 132 Mg/ha and 66.02 Mg/ha, while the plantation established in 2015 had the lowest biomass density and carbon stock (Mg/ha) with 69.98 Mg/ha and 34.99 Mg/ha. Overall, the estimated total monetary value of Bakhawan Eco-Park of 250 hectares mangrove plantation in New Buswang, Kalibo, Aklan is PhP 2994771.63.

Productivity of Pangi (Pangium edule Reinw.) and biodiversity of agroforestry systems at various altitudes in Toraja Regency, South Sulawesi

There are two important things that farmers consider in selecting and developing plant species in their agroforestry system, namely productivity and suitability to the site. This study aims to determine the productivity of the pangi crop and the biodiversity of the agroforestry system at different altitudes. This research was conducted from June to November 2018 at three different altitudes, namely in Lembang Palesan (Rembon District) which represents an altitude of <600 m above sea level, Lembang Turunan (Sangalla District) which represents an altitude of 800-850 m above sea level, and Lembang Gasing (Mengkendek District) which represents an altitude of > 1000 m above sea level. The research method used is a survey method with the placement of sample plots by Purposive Sampling. The sample plot size is 20m x 50m or 0.1 ha. At each different altitude, 10 sample plots were made, so the number of sample plots was 30. The parameters measured were pangi fruit production, tree diameter and height and recorded all plant species in the sample plot. Data analysis was carried out quantitatively and descriptively, while agroforestry system plant species diversity was identified using vegetation analysis methods. The results showed that the fruit production of the pangi plant, density, LBDS and diameter of the pangi tree were significantly different at each different altitude and the largest was at an altitude of 800-850 m above sea level, but the number of plant species and the diversity of plant species at each altitude were relatively the same in the medium category, as well as the density of all types of plants, and the average height of pangi trees were not significantly different at each different altitude. Thus, it is not recommended that pangi crop be developed at an altitude above 850 m above sea level.

IDENTIFICATION OF MEDICINE PLANTS IN THE SRIWIJAYA BOTANICAL GARDEN, BAKUNG VILLAGE, INDRALAYA UTARA DISTRICT, OGAN ILIR REGENCY, SOUTH SUMATRA PROVINCE

This study aims to determine and identify the composition and type of structure medicinal plants in the Sriwijaya botanical garden through analysis of medicinal plant vegetation by using a species diversity index. The research method used was a survey with a sampling technique used was a sampling method or intentionally from the area of the Sriwijaya Botanical Garden conservation area. Using the formula for sampling intensity [IS] of 2% and a total area of 100 Ha, the number of sample plots obtained is 50. This study identified 43 families and 76 species of medicinal plants. The highest importance index (INP) of the lower plants in the lower plantswas Senduduk (Melastoma malabathricum) a value 29,797%, while the lowest INP is Cataract (Laurentia longifora), Curry Leaf (Murraya koenigii), Kumis Kucing (Orthosiphon aristatus) a 0,724%. While in INP, the highest mastery of medicinal plants at sapling level is Jelutung (Dyera costulata) a value 40.741%, while the lowest INP a butterfly (Bauhinia porpurea) with 4.204%. The diversity indexes of medicinal plants at the understorey and sapling levels were found to be 2.00 and 1.03, in both, indicating that understorey and sapling diversity was moderate and the community state was very stable. While the diversity index of medicinal plants at the seedling level was 0.94, indicating that medicinal plant diversity at the seedling stage is poor and the community state is quite poor.

THE INFLUENCE OF STAND DENSITY AND SPECIES DIVERSITY INTO TIMBER PRODUCTION AND CARBON STOCK IN COMMUNITY FOREST

Stand density and species diversity are two indicators that are highly related to forest productivity. However, the effect of those variables on the productivity of community forest is rarely documented. This study evaluates the influence of stand density and species diversity on timber production and carbon stock in the community forest. The study area was located in Madiun District. A field survey was conducted in four different community forest sites, i.e. Morang, Kuwiran, Randualas, and Kare. The sampling technique was by quadrat method using a sample plot size of 25 m x 25 m. The number of sample plots used in this study was 64 units, which were evenly distributed in every site. Comparison of stand attributes among sites was examined by Kruskal-Wallis test and followed by Kruskal-Nemenyi test on the effects of stand density and species diversity on timber production and carbon stock were assessed separately for each parameter using the generalized least square regression test. The process of statistical analysis was applied using a significance level of 5%. Results show a significant difference in stand volume, aboveground biomass, and carbon stock among sites (P&lt;0.05). This study also recorded a meaningful effect of stand density and species diversity on timber production and carbon stock of community forest, wherein stand density provided a higher effect (R2 = 0.68; P&lt;0.05) than species diversity (R2 = 0.26; P&lt;0.05).

Effects of tree species and topography on soil and microbial biomass stoichiometry in Funiu Mountain, China

BackgroundSoil and microbial biomass stoichiometry plays an important role in understanding nutrient cycling in terrestrial ecosystems. However, studies on soil and microbial biomass stoichiometry in forests are rare. This study investigated the effect of tree species and topographic factors on the ecological stoichiometry of soil and soil microbial biomass.MethodsThree types of forest stands (Quercus variabilis, Larix principis-ruprechtii, and Cotinus coggygria Scop.) in the Beiru River basin of Funiu Mountain were analyzed in September 2018. Six slope positions (sunny bottom slope, sunny middle slope, sunny top slope, shady bottom slope, shady middle slope, and shady top slope) were selected, and the total number of sampling plots was 108. The stoichiometric indices of soil and microbial biomass were determined.ResultsAt a depth of 0–10 cm, the soil organic C contents in different stands followed the order of C. coggygria (27.7 ± 5.2 g/kg) > Q. variabilis (24.5 ± 4.9 g/kg) > L. principis-ruprechtii (20.8 ± 4.3 g/kg) (P < 0.05). The soil organic C contents at depths of 0–10 cm with different slope aspects and at different slope positions also showed significant differences (P < 0.05). The highest MBC content was observed at the slope bottom (1002 ± 157 mg/kg), whereas the lowest was observed at the slope top (641 ± 98.3 mg/kg). Redundancy analysis showed that the contribution of tree species to these differences was 57.1%, whereas that of topographical factors was 36.2%.ConclusionsTree species more significantly affected soil nutrients and microbial biomass C, N and P than did topographic factors.

Effect of cluster configuration and auxiliary variables on the efficiency of local pivotal method for national forest inventory

ABSTRACTPlanning a forest inventory comprises making decisions related to the sampling strategy: cluster configuration, sample size and sample allocation within the survey area. Cluster configuration includes deciding on the number of sample plots within the cluster and distances between them. Available resources set the limit for field work in terms of man-days. If the time consumption for measurements is known, the sample size can be determined under the constraint. In this study, we simulated the second phase of inventory sampling with fixed time resources by replicating sample selection with a spatially balanced sampling utilizing local pivotal method (LPM) for different cluster configurations to find the most efficient. As a result, the temporary cluster configuration was changed from 9 to 5-sample plot configuration in a pilot inventory. Further, the sample selection was performed with LPM having total growing stock volume and broadleaf volume proportion as auxiliary information. The pilot results were aligned with the time series in respect to forest area and total growing stock volume, but in tree species groups deviations were observed in growing stock volume. A more comprehensive optimization should include the travelling routes, the plot-to-plot distances and the plot design. In any case, the result is region specific.

The effects of sample plot selection strategy and the number of sample plots on inoptimality losses in forest management planning based on airborne laser scanning data

In forest management planning, errors in predicted stand attributes might lead to suboptimal decisions that result in decreased net present value (NPV). Forest inventory data will have higher value if the amount of suboptimal decisions can be decreased. Therefore, the value of information can be measured through the decrease in inoptimality losses, which are the NPV differences between the optimal and suboptimal decisions. In this study, four alternative sample plot selection strategies with different numbers of sample plots were compared in terms of expected mean inoptimality losses. Stand-level mean inoptimality losses varied between €41.1·ha–1 and €80.7·ha−1, depending on the sample plot selection strategy and the number of sample plots used as training data in the k-nearest neighbors imputation method. Mean inoptimality losses decreased substantially when the number of sample plots increased from 25 to 100, and the decreasing trend continued until 500 sample plots. Total inoptimality losses can decrease by approximately €1 million in an inventory area of 100 000 ha when the number of sample plots is increased from 100 to 500. The measurement of more sample plots can be justified as long as the field measurement costs do not exceed the decrease in inoptimality losses.

Estimating volume growth from successive double sampling for stratification

Volume growth is a key indicator in forest management and planning and, accordingly, an integral part of the estimation procedure of forest resources from sample based inventories. Growth estimation from successive double sampling for stratification (2SS) is somewhat challenging and has not been sufficiently addressed in the pertinent literature. Applying 2SS on successive occasions, with updated stratification on each occasion, may lead to fluctuation of sampling units among the strata and to a certain number of sample plots that have to be discarded or that have to be newly established on the second occasion, to obtain the required per-strata sampling proportions, which are stipulated in advance. After presenting a notation to implement growth estimation into 2SS standard formulas, the question of strata shifts and the occurrence of discarded and of new sample plots in the context of growth estimation is addressed. Although growth, unlike net change, can only be estimated from direct observations on remeasured sample plots, it was shown that ignoring discarded or new plots might lead to severely biased estimators. Modified estimators for mean growth and variances are provided and their application is illustrated using data from a repeated survey in a central German forest district.

JENIS-JENIS TANAMAN DI LAHAN GARAPAN PETANI KPPH WANA MAKMUR DALAM TAHURA WAN ABDUL RACHMAN

The increasing needs and the nearness residential distance from the forest were several factors that caused society to do the utilization of the forest land. Sungai Langka village was a village directly adjacent to the Wan Abdul Rachman great forest park area, where most societies were farmers who manage the land inside the Wan Abdul Rachman great forest park area. The objective of this research i.e.: 1) To find out the species of plants cultivated by farmers on the land-based on habitus, plant groups, and commodities produced; 2) to count the density of each plant group; 3) to find out the most plants as a source of farmers incomes. This research was conducted with a vegetation survey using the terraced line method. The number of sample plots used was 69 pieces measuring 20m x 20m, 10m x 10m, 5m x 5m, and 2m x 2m. The results of the study showed that there were 35 plants species on farmers cultivated land which is dominated by plants of the forest group MPTS with a density of 3,637.66 individuals/ha, forest wood plant 797,83 individuals/ha, agricultural MPTS 2,294.2 individuals/ha, and agricultural crops 1,533.34 individuals / ha. Therefore, could be concluded that most of the plants on arable land were fruit-producing plants which were partially included in the MPTS forest group plants, and farmers rely on crops such as cocoa, banana, durian, clove, nutmeg, rubber, petai, pepper and vanilla as the source of income and fulfill their needs.

Identification of Medicinal Plants in The Area of KPPH Farmer at Talang Mulya on Wan Abdul Rachman Great Forest Park

Forests are a source of various types of medicinal plants. Plants that live wildly in forest areas are also included in the Forest Park area, Wan Abdul Rachman. Type identification is the first step for the use and preservation of these medicinal plants. Therefore a study was conducted which aims to determine the types, density of each population and the degree of dominance of each population of medicinal plants. This research was carried out in the farmer's group cultivated area of Kelompok Pengelola dan Pelestari Hutan (KPPH) Talang Mulya Tahura Wan Abdul Rachman. This research was conducted using a double plot method. The number of sample plots is 87 plots, each measuring 2m x 2m. The variables observed included plant species, the density of each population and the degree of dominance of each population of medicinal plants. The results of this study were identified 29 types of medicinal plants belonging to 18 plant families. The majority of medicinal plants are dominated by awar-awar, while the lowest is the curcuma and pepper. There are quite a lot of medicinal plants in the area cultivated by KPPH Talang Mulya farmers, but there are medicinal plants which are threatened by populations such as temulawak, allegedly because they are used by the community without cultivation.Keyword: forest, forest park, medical plants.

Remotely sensed data controlled forest inventory concept

ABSTRACTNowadays, the image of the forest in Germany is changing from monoculture areas to very mixed forests, where individual stands are no longer clearly visible. The objective of this study was to examine the use of remotely sensed data at enterprise level for pre-stratification and sample plot allocation in the planning stage of forest inventories in a very heterogeneous forest. On the basis of RapidEye satellite data and object-based image analysis, a stratified segment-based non-permanent sampling design was developed and evaluated against the results of a permanent systematic sampling design. The relative efficiency (RE) was calculated based on variance estimators for simple random sampling and stratified random sampling for the variable timber volume [m3/ha]. By stratification of the sample designs, we achieved an RE of 1.25 for the systematic sampling and 1.34 with the segment-based sampling design. Based on a targeted standard error of 4.6%, the sampling designs were compared with respect to the required sample size. The stratified segment-based sampling design reduced the number of sample plots compared to the systematic sampling design by 28%. Furthermore, it was shown that the possible reduction of sampling plots leads to a cost saving of 21%.

Above Ground Biomass Estimation of Dalbergia sissoo Forest Plantation from Dual-Polarized ALOS-2 PALSAR Data

ABSTRACTIn this study, ALOS-2 PALSAR L-band dual-pol (HH and HV) synthetic aperture radar (SAR) images were used for above ground biomass (AGB) estimation of Shisham (Dalbergia sissoo) tree species in the managed forest of Chichawatni Irrigated Plantation, Sahiwal District, Punjab, Pakistan. A total of 15 plots were surveyed during the field campaign and locally developed tree species-specific allometric equation was used for AGB calculation. The SAR images were pre-processed and calibrated to sigma nought (dB) for statistical AGB modeling. Nonlinear regression models between field-based AGB (ton/ha) and SAR backscatter sigma nought (dB) values give R2 (0.47 and 0.55) and RMSE (1.18 and 1.87) values for HH and HV-pol data, respectively. AGB maps generated through these regression models from both HH and HV-pol data show similar AGB values and spatial patterns. Due to a small number of sample plots, the Leave-One-Out Cross-Validation (LOOCV) proxy validation method was used for model validation, between estimated and predicted backscatter sigma nought (dB) values. The validation R2 values are small; however, outliers are identifiable in the validation scatterplots. The AGB maps from this study are useful as a first estimate of AGB values from remote sensing in the study region, especially in the context of the REDD+ program.

Kondisi Populasi Dan Pola Penyebaran Anggrek Eria Spp. Di Resort Balik Bukit Taman Nasional Bukit Barisan Selatan

Forest area of Balik Bukit Resort allocated as regions of natural preservation. This area hasmany potential/natural resources that could be developed. This area is located at BukitBarisan Selatan National Park which have diverse types of flora, including various types oforchids. Approximately there were 154 typeof orchids in this area(Indonesia Institute ofSciences, 2011). This research aims were to know the population and distribution patterns ofEria spp orchids.This research was conducted in August 2015. The method used is the doubleplots systematically method with sampling intensity (SI) 0.1%. The size of each swath of 20 mx 20 m and the total area of the Balik Bukit Resort was 3,560 ha, so that the total number ofsample plots were 90 units. The observed variables were types of Orchid, Orchid populationsand patterns of spread of Eria spp. Based on the results of the study, there were 10 different types of Eria spp.. Eria iridifolia found most of 22.50 individuals/ha compared to other typesof orchids Eria. Followed by the type of E. erecta of 14.72 individuals/ha E. flavescens andtype of 8.33 individuals/ha. Whereas other types is E. discolor, E. javanica, E. junghunii, E.mucronata, E. oblitterata, E. retusa, E. robusta has a density of 1 — 4 individuals/ha.Distribution pattern of the orchids E. discolor, E. erecta, E. flavescens, E. iridifolia, E.javanica, E. mucronata, E. obletterata, and E. retusa enter into the category of a huddle.While the orchids E. junghunii belonging to the category of uniform and the orchids E.robusta into random categories.Keywords: distribution pattern, Eria spp. orchids, population

Rapidly Increasing Invasion of Eastern Texas Forestlands by the Most Prevalent Invasive Shrubs: Chinese and European Privets

Abstract Based on analyses of an extensive set of field data collected by the US Forest Service, we identified trends in range expansion of Ligustrim sinense (Chinese Privet) and L. vulgare (European Privet), the most prevalent invasive shrubs within forestlands of eastern Texas. Chinese and European privets increased markedly in northeastern Texas from 2004 and 2012. The number of sample plots in which Chinese and European privets were detected increased from 79 (in 25 counties) to 300 (in 40 counties), and the mean percent coverage within those sample plots already invaded in 2004 increased significantly by 2012. The number of sample plots in each of 3 percent-coverage categories ( 20) increased in each of 2 longitudinal bands (>95°W and ≤95°W) from the first to the second survey. Our empirical results support the general trend of westward and southeastward expansions predicted by existing models, which were based on less -recent data.

Recent Range Expansions by Chinese Tallow (Triadica sebifera (L.) Small), the Most Prevalent Invasive Tree in the Forestlands of Eastern Texas

Abstract We documented range expansion of Triadica sebifera (Chinese Tallow) within forestlands of eastern Texas based on field data collected by the US Forest Service from 2001 to 2012. Chinese Tallow generally spread northward, with the number of sample plots in which Chinese Tallow was detected approximately doubling and mean percent coverage of Chinese Tallow in sample plots increasing significantly (t = -3.93, P 40) increased in each of 3 latitudinal (°N) bands (29–30, 30–31, >31) from the first to the second survey. Our empirical results support the general trend of northward expansion predicted by existing models, which were based on less-recent data.

Land‐use history exerts long‐term effects on the clear‐cut flora in boreonemoral Sweden

AbstractQuestionsCan signs of 19th century grassland management, which can be observed in the flora immediately (2–4 yrs) after clear‐cutting in boreonemoral Sweden, still remain 4 yrs later? Do the effects from the time since clear‐cutting differ between forest and grassland plant species?LocationProvince of Östergötland, southern Sweden.MethodsTwelve contemporary clear‐cut areas that were once meadows and 12 that were once forests were selected using land‐use maps from the 1870s. Grasses and herbaceous plants were surveyed twice, once in 2009 and once in 2013 (2–4 and 6–8 yrs after clear‐cutting, respectively). Plant presence was recorded within 100 circular sample plots (radius 1 m) placed evenly throughout each respective clear‐cut area along transects spaced 25‐m apart. The number of sample plots in which a species was present was taken as a measure of that species' frequency. Random effects meta‐analysis, odds ratios and ANCOVA were used to analyse species responses to clear‐cutting over time.ResultsA total of 170 plant species were found in the study, of which 33 were classified as grassland indicator species and 31 as plants primarily confined to forests. Clear‐cut areas with a history as meadowland had, on average, up to 64% higher total species richness and 110% more grassland indicator species than did clear‐cut areas with a history as forest. The time since clear‐cutting had no effect on total species richness. However, the odds of finding a grassland indicator species decreased with the time since clear‐cutting, whereas the odds of finding a forest species increased.ConclusionsWe concluded that land‐use history plays an important role in explaining the flora found in Swedish clear‐cuts, and that its effects on species richness remain for a minimum of 8 yrs after harvest (conservative estimate). This phenomenon highlights the importance of acknowledging land‐use legacies in ecological research and conservation. Future studies should investigate various options for the promotion of grassland plants in clear‐cuts with a history of grassland management while also acknowledging the potential conflicts between conservation and production. The results may pertain to other countries with similar land‐use histories.

Inventory of aspen trees in spruce dominated stands in conservation area

The occurrence of aspen trees increases the conservation value of mature conifer dominated forests. Aspens typically occur as scattered individuals among major tree species, and therefore the inventory of aspens is challenging. We characterized aspen populations in a boreal nature reserve using diameter distribution, spatial pattern, and forest attributes: volume, number of aspens, number of large aspen stems and basal area median diameter. The data were collected from three separate forest stands in Koli National Park, eastern Finland. At each site, we measured breast height diameter and coordinates of each aspen. The comparison of inventory methods of aspens within the three stands was based on simulations with mapped field data. We mimicked stand level inventory by locating varying numbers of fixed area circular plots both systematically and randomly within the stands. Additionally, we also tested if the use of airborne laser scanning (ALS) data as auxiliary information would improve the accuracy of the stand level inventory by applying the probability proportional to size sampling to assist the selection of field plot locations. The results showed that aspens were always clustered, and the diameter distributions indicated different stand structures in the three investigated forest stands. The reliability of the volume and number of large aspen trees varied from relative root mean square error figures above 50% with fewer sample plots (5–10) to values of 25%–50% with 10 or more sample plots. Stand level inventory estimates were also able to detect spatial pattern and the shape of the diameter distribution. In addition, ALS-based auxiliary information could be useful in guiding the inventories, but caution should be used when applying the ALS-supported inventory technique. This study characterized European aspen populations for the purposes of monitoring and management of boreal conservation areas. Our results suggest that if the number of sample plots is adequate, i.e. 10 or more stand level inventory will provide accurate enough forest attributes estimates in conservation areas (minimum accuracy requirement of RMSE% is 20%–50%). Even for the more ecologically valuable attributes, such as diameter distribution, spatial pattern and large aspens, the estimates are acceptable for conservation purposes.