Field Inventory Research Articles

Possibilities of quantitative and qualitative inventory of drainage devices based on selected maps and photogrammetric images

Abstract The aim of the work was to analyse which of the selected geodetic and cartographic materials (maps and high resolution aerial images) are useful for inventory of water drainage devices. Obviously, correct determination of their quantitative and qualitative statuses can be made through field inventory. Quantitative inventory can also be done on the basis of maps. For the purpose of this research, an analysis was carried out which consisted of checking which of the selected cartographic and photogrammetric materials best reflect the location of irrigation devices in the field. The analyses were based on both digital and analogue maps at the scale of 1 : 50 000 to 1 : 5 000. The selected photogrammetric materials included images at the scale of 1 : 10 000 and 1 : 1000.

Lidar supported estimators of wood volume and aboveground biomass from the Danish national forest inventory (2012–2016)

National forest inventories (NFI) provide estimates of forest resources at the national and regional level but are also increasingly used as basis for mapping forest resources based on remotely sensed data. Such maps procure local estimates of forest resources but may also improve precision of national and regional estimates. Supported by a countrywide airborne laser scanning (circa 2014) and a national land-use map (circa 2014), direct (DI), model-assisted (MA), and model calibrated (MC) estimates of wood volume (V) and aboveground biomass (AGB) densities in forest areas derived from the Danish NFI (2012–2016) are presented. Nonlinear models with three LiDAR metrics are used to predict V and AGB in forested areas. According to these models, the predicted values of V and AGB in sample plots missed in the field inventory was lower than in those visited in the field; we therefore opted for estimation with multiple (stochastic) imputations. MA estimates for the country suggested a 2% lower level of both V and AGB densities with errors 45% lower than estimated errors in DI results. National MC estimates were close to the DI estimates with an error approximately 40% lower than errors in DI estimates yet 5% greater than the MA estimates of error. Multiple imputations had the strongest impact on DI estimates, but only a weak impact on MA and MC results.

Geological heritage as a new kind of natural resource in the Siwa Oasis, Egypt: The first assessment, comparison to the Russian South, and sustainable development issues

Discovering new natural resources is important for sustainable development of remote oases in arid regions of Africa and the Middle East. The first comprehensive assessment of geological heritage of the Siwa Oasis in the northwestern part of Egypt is based on field inventory of potentially unique geological features and analysis of literature data. Comparison to similar features in the other parts of Egypt and the world, including the Russian South, is essential to evaluate the uniqueness of the described geological phenomena. A total of nine geological heritage types are established in the Siwa Oasis. These include stratigraphical, palaeontological, sedimentary, palaeogeographical, hydrological and hydrogeological, geothermal, pedological, geomorphological, and economical types. The most high-ranked are features constituting sedimentary, palaeogeographical, and hydrological and hydrogeological types. The former can be found in the old Shali town built from evaporite stones experienced diagenetic changes, and the latter is local manifestation of the Eocene–Oligocene palaeoenvironmental transition different from the global cooling trend. Additionally, saline lakes and pools, as well as stratigraphical sections, landforms, and some other features demonstrate certain uniqueness. A series of geosites are identified in the oasis and vicinities. Taken together, the geological heritage of the Siwa Oasis is significant for conservation and exploitation for research, education, and tourism purposes. It is suggested that geological tourism there should be combined with archaeological, industrial, and "ordinary" to become efficient and to contribute to the local sustainable development. Examples from the Russian South (the Big Tambukan and Big Yashalta lakes) permit to realize that the consideration of salt and therapeutic mud resource indicates on the higher value of the discussed geological heritage features of the Siwa Oasis. Moreover, this resource, which is of big uniqueness itself, can contribute substantially to tourism development on the basis of unique geological phenomena.

A Generalized Lidar-Based Model for Predicting the Merchantable Volume of Balsam Fir of Sites Located along a Bioclimatic Gradient in Quebec, Canada

Lidar-based models rely on an optimal relationship between the field and the lidar data for accurate predictions of forest attributes. This relationship may be altered by the variability in the stand growth conditions or by the temporal discrepancy between the field inventory and the lidar survey. In this study, we used lidar data to predict the timber merchantable volume (MV) of five sites located along a bioclimatic gradient of temperature and elevation. The temporal discrepancies were up to three years. We adjusted a random canopy height coefficient (accounting for the variability amongst sites), and a growth function (accounting for the growth during the temporal discrepancy), to the predictive model. The MV could be predicted with a pseudo-R2 of 0.86 and a residual standard deviation of 24.3 m3 ha−1. The average biases between the field-measured and the predicted MVs were small. The variability of MV predictions was related to the bioclimatic gradient. Fixed-effect models that included a bioclimatic variable provided similar prediction accuracies. This study suggests that the variability amongst sites, the occurrence of a bioclimatic gradient and temporal discrepancies are essential in building a generalized lidar-based model for timber volume.

Investigating patterns of in-channel wood deposition locations in a low-gradient, variably-confined alluvial river system

In-channel large wood (LW) plays an important role in the eco-morphological functionality of many river systems. This importance has been widely recognized, yet there continues to be a poor understanding of relationships between morphodynamics and locations of wood deposition within the channel, particularly in low-gradient, semi-confined rivers. This research investigates the following hypotheses: 1) LW deposition locations (DLs) occur periodically in relation to the periodic arrangement of morphological features in the Big River, Missouri, USA, a low-gradient, variably-confined, alluvial river system; 2) geomorphic controls on DLs in the Big River exert varying levels of influence at different spatial scales. A large-scale field inventory of LW DLs was performed along the Big River. A spectral analysis was then used to identify periodic patterns of DLs along the Big River and various statistical tests of association were used to investigate the relationships between DLs and morphological variables, and between periodicity (where identified) and morphological variables. The results suggest that under certain circumstances, DLs are spatially periodic, with periodicities ranging from 270 m to 1371 m, and in some cases exhibit periodicity at different spatial scales. Regression analysis was unable to statistically associate periodicity with morphological features; however, correlation and stepwise Poisson regression models suggest that channel-scale (100 m to 500 m) sinuosity, and valley width exert more influence on DLs than other variables. The lack of strong statistical associations suggests that either 1) LW dynamics in the Big River contain a high level of stochasticity or 2) controlling variables were not included in this analysis. These results support the need for better theoretical and numerical models of stochastic LW processes in order to better manage LW in complex geomorphic systems.

F3: Simulating spatiotemporal forest change from field inventory, remote sensing, growth modeling, and management actions

Abstract Contemporary forest management requires highly-detailed, spatially-contiguous, multi-temporal, and scenarios-comparable forest conditions. Field inventories and individual-tree models often contain highly-detailed data and allow for long-term complex scenarios comparison, but the information is only at sampled locations and lacks complete spatial coverage. Forest landscape models (FLMs) provide landscape-level spatiotemporal data, but the details that are important to land managers are often lost in the generalized outputs. We developed a modeling framework, F3, to integrate FIA (Forest Inventory and Analysis) plots, the Forest Vegetation Simulator (FVS), and FastEmap (Field And SatelliTe for Ecosystem MAPping) to simulate spatiotemporal forest change under natural succession and vegetation management. F3 extrapolates the details of forest inventory plots and individual-tree model outputs to a spatially-contiguous landscape by fusing tree-list field measurements, individual tree growth and yield models, remote sensing and environmental geospatial datasets. F3 allows for area-specific management action simulations. F3 compares FVS results with field measurements for temporal accuracy assessment and uses a leave-one-out cross-validation for spatial accuracy assessment. F3 adopts parallel computation techniques to implement the modeling in an automatic and efficient manner. The proof of concept of F3 was demonstrated in Tahoe National Forest (TNF) showing spatiotemporal changes on six forest structural metrics (quadratic mean diameter, basal area, biomass, habitat suitability index, canopy cover, and coarse woody debris) under natural succession, regeneration-cut, and thinning scenarios for the years 2014–2114 at a 30 m resolution. F3 can be used for initializing FLMs and for analyzing a wide range of ecosystem services; however, the under-representation of certain forest types in the FIA plot data set, the modeling bias from FVS, and choice of FastEmap covariates contribute to major uncertainties in the framework.

Close-range laser scanning in forests: towards physically based semantics across scales.

Laser scanning with its unique measurement concept holds the potential to revolutionize the way we assess and quantify three-dimensional vegetation structure. Modern laser systems used at close range, be it on terrestrial, mobile or unmanned aerial platforms, provide dense and accurate three-dimensional data whose information just waits to be harvested. However, the transformation of such data to information is not as straightforward as for airborne and space-borne approaches, where typically empirical models are built using ground truth of target variables. Simpler variables, such as diameter at breast height, can be readily derived and validated. More complex variables, e.g. leaf area index, need a thorough understanding and consideration of the physical particularities of the measurement process and semantic labelling of the point cloud. Quantified structural models provide a framework for such labelling by deriving stem and branch architecture, a basis for many of the more complex structural variables. The physical information of the laser scanning process is still underused and we show how it could play a vital role in conjunction with three-dimensional radiative transfer models to shape the information retrieval methods of the future. Using such a combined forward and physically based approach will make methods robust and transferable. In addition, it avoids replacing observer bias from field inventories with instrument bias from different laser instruments. Still, an intensive dialogue with the users of the derived information is mandatory to potentially re-design structural concepts and variables so that they profit most of the rich data that close-range laser scanning provides.

Modelling above-ground live trees biomass and carbon stock estimation of tropical lowland Dipterocarp forest: integration of field-based and remotely sensed estimates

ABSTRACTCarbon exists as carbon dioxide (CO2) which is one of the greenhouse gases (GHG) in the atmosphere that has an enormous influence on the impact of climate change. Therefore, the forest plays an undeniably pivotal role as a carbon sink, which absorbs carbon dioxide from the atmosphere. This research aims to develop allometric equation for above-ground live tree biomass (AGB) by combining field-based, combination of field data observation and technology (WV-3 and light detection and ranging (lidar)) and by using only technology derivation. The independent predictor was induced based on the literature review and theories, and an ordinary least square (OLS) estimator will be used to develop multiple linear regression models. During model selection, the best model fit was selected by calculating statistical parameters such as residual of the coefficient of determination (R2) selection methods, adjusted coefficient of determination (R2adj), root mean square error, graphical analysis of the residuals, standard error (Syx), and Akaike information criterion. An allometric equation of this research was developed using carbon stocks as dependent variables, and four of the predictor’s variables: diameter at breast height (DBH); total height observed at field (hF); total height derived from airborne lidar (hL); and morphometric variables of the crown projection area (CPA). Based on the statistic indicators, the most suitable model is Model 1, ln (Sc) = – β0 + β1 ln (hL) + β2 ln (DBH) + β3 ln (CPA) for the combination of remote sensing and field observation; ln (Sc) = – β0 + β1 ln (hF) + β2 ln (DBH) for field inventory only; and ln (Sc) = – β0 + β1 ln (hL) + β2 ln (CPA) for remote sensing only. This model is reliable in forest management to estimate the AGB and carbon stock estimation using a selection of variable sources.

Impacts of Downtown Developments to Facilitate Environmental Sustainability and Presence of Core and Frame: A Case Study of Saddar, Karachi, Pakistan

A real sustainable world and a livable environment for everyone is currently needed and becoming an extraordinarily challenging task. Sustainability for whom-who benefits and who loses? The increasing environmental problems are also hampering the sustainability. The remarkable increase in population and severe food shortages has brought unprecedented burden on land.Land is considered as space, territory, location, ecosystem, reserve and human habitat above all. Land-use provides a basis for identification of different functional zones in the city thus providing a framework for shaping the internal structure of a city. The best-planned development of any area is possible when the problems of that area are well understood, well documented and closely monitored. Systematic information on land-use / land cover classes, environmental problems and the available arrangement is critically important for future planning of an area.The rationale of this study is to indicate the presence of core and frame in the downtown area of Saddar, Karachi and to examine how finished downtown developments are designed to facilitate environmental sustainability. The field inventory has been conducted to find out the functional and physical developments and sustainability of the study area. In addition the process models have been applied to find out the environmental sustainability. The results of filed investigations show that Saddar does not fulfill the requirement of any of the classical land use models. With reference to the planned development of the core area, zoning laws should be applied to place the functions properly to their respective location. The main problems should be considered as prime matters for the city planners and agencies.

Woody material structural degradation through decomposition on the forest floor

Dead woody material (DWM) plays numerous important roles in forest ecosystems; however, through the process of decomposition, it undergoes structural and chemical changes that progressively alter its function in these roles. Much remains unknown about how DWM mechanical strength and structural integrity change through decomposition in natural forest settings. We assessed changes in wood strength (bending strength, compressive strength, and surface hardness) using standard wood stakes of known initial mass from three species. The stakes were placed in forested settings for two and four years before collection for laboratory analyses. All three strength metrics decreased as stakes lost mass due to decay; however, bending strength had the strongest relationship with mass loss, a result that was consistent for all species, as well as species-pooled data. Results for all strength-loss metrics indicate that stakes had experienced ca. 10% strength loss before any detectable mass loss had occurred. Further, our results suggest that the decay class system typically used during field inventories — based in large part on tactile assessments of wood structural integrity — may provide a reasonable characterization of DWM mass loss, which is a critical assumption for carbon accounting and modelling based on inventory data.

Allometric models for managing lowland miombo woodlands of the Beira corridor in Mozambique

Appropriate allometric models are urgently needed to assess the status and changes in biomass and carbon of the trees in miombo woodlands occupying large geographical areas in Mozambique. This study developed two new and interchangeable allometric models for estimating total above-ground biomass (AGB) of lowland miombo woodlands in the Beira corridor, central Mozambique, based on stem diameter at breast height (DBH) and stump diameter (SDI). The Beira corridor study area covers approximately 29,000 km2, of which about three-quarters is lowland miombo woodland. The SDI-based model is proposed principally for estimating total AGB (stem, branches, foliage) of harvested trees/shrubs when diameter cannot be measured at breast height, and thus to reconstruct the former biomass in forests subjected to logging, or clear-cutting for agriculture.The DBH-based model and SDI-based model were fitted using data on a destructive sample of 155 trees, which were representative of tree sizes (diameter and height) and tree species in the Beira corridor area. The following allometric models were developed: DBH-based model [tDW (kg tree−1) = 0.1754 * (DBH) 2.3238], with prediction performance, i.e. adjusted R-squared 98–99%; and SDI-based model [tDW (kg tree−1) = 0.08495 * (SDI) 2.3987], with prediction performance 86–96%. Carbon comprises 50% of biomass. Both the DBH- and SDI-based models can be used for estimating total AGB of lowland miombo woodlands with a high degree of reliability, based on field inventory within the Beira corridor region. Evaluation of the mathematical and statistical credibility of these models, which was carried out on the construction dataset (verification procedure) and independent dataset (validation procedure), gave satisfactory results. Moreover, when applied on our data, these models were more appropriate for the Beira corridor than allometric models found in the literature. However, application of both models should be restricted to the lowland miombo type in the Beira corridor, not mountain miombo.

The Carbon Sinks and Mitigation Potential of Deodar (<i>Cedrus deodara</i>) Forest Ecosystem at Different Altitude in Kumrat Valley, Pakistan

Forest carbon monitoring and reporting are critical for informing global climate change assessment. The regional estimates of forest carbon attached greater attention, to assess the role of forest in carbon mitigation. Here using field inventory, we examined the carbon sink and mitigation potential of monospecific Deodar forest in the Kumrat valley, of Hindu Kush Himalaya, Region of Pakistan, at a different elevation. The elevation of monospecific Deodar forest ranges from 2300 to 2700 m (a.s.l). We divided the forest into three elevation classes (that is 2300 - 2400 m (EI) 2400 - 2500 m (EII) and 2500 - 2700 m (EIII) a.s.l respectively). In each elevation class, we laid out 09 sample plots (33*33 m2) for measuring carbon values in living tree biomass (LT), soil (SC), litter, dead wood, cone (LDWC) and understory vegetation (USV). Our results showed that the carbon density at EI was 432.37 ± 277.96 Mg·C-1, while the carbon density at EII and EIII was 668.35 ± 323.94 and 1016.79 ± 542.99 Mg·C-1 respectively. Our finding revealed that the carbon mitigation potential of the forest increases with increasing elevation. Among the different elevation classes, EIII stored significantly higher carbon due to the dominance of mature, old age, larger trees, and the minimum anthropogenic disturbance, whereas EI stored statistically lower carbon because of maximum anthropogenic disturbance, which resulted in the removal of mature and over-mature trees. Furthermore, our correlation analysis between tree height and carbon stock and basal area and LT carbon, underlines that the basal area is the stronger predictor of LT carbon estimation than height. Overall our results highlight that deodar forest stored 716.94 ± 462.06 Mg?C·ha-1. However, the rehabilitation, preservation and sustainable management of disturb forest located at a lower elevation could considerably improve carbon mitigation potential.

Uncovering the diversity of dog-faced bats of the genus Cynomops (Chiroptera: Molossidae), with the redescription of C. milleri and the description of two new species

Until recently the genus Cynomops (Chiroptera: Molossidae) comprised six species of fast flying, aerial insectivorous bats distributed throughout the Neotropics. However, our revisionary study have shown that the diversity of this taxon was underestimated as molecular and morphological data supported the recognition of C. milleri as a full species and revealed two previously unrecognized small species of Cynomops. These newly recognized taxa are Cynomops freemani sp. nov. from the Canal Zone region, Panama, sister taxon to C. mexicanus, and Cynomops tonkigui sp. nov. from the eastern Andes of Ecuador and Colombia, sister taxon of C. milleri. We also describe the calls of Cynomops freemani sp. nov. that may be useful for the recognition of this species during field inventories based on ultrasonic recording techniques. We elevate the currently known diversity of Cynomops to eight species, as we also revalidate C. milleri providing an emended diagnosis and a redescription of this taxon.

Variation in the species richness of parasitoid wasps (Ichneumonidae: Pimplinae and Rhyssinae) across sites on different continents

Abstract The old idea that parasitoid wasps (Ichneumonidae) show an inverse latitudinal diversity gradient has recently been challenged, but how ichneumonid species richness varies across the globe is still not well understood. We carried out field inventories in 21 sites on three continents to clarify this question, focusing on the subfamilies Pimplinae and Rhyssinae. Our total sampling effort was 628 Malaise trap months and the total catch exceeded 65 000 individuals. Our main focus was in two intensively inventoried areas in Amazonia, together yielding 257 Malaise trap months and 26 390 ichneumonid individuals. To expand the scope and assess global species diversity patterns of the Pimplinae and Rhyssinae, we compiled published species lists from a total of 97 study localities around the world. The highest observed species richness in any locality, 105 species, was found in one of our field sites in Peruvian Amazonia. None of the other localities reported more than 70 species, even the ones with a sampling effort comparable to ours. Despite the local thoroughness of our field inventories in Amazonia, data analyses indicated that a substantial proportion of the parasitoid wasp species occurring in each site remained unobserved. The highest local species richness values were reported from the tropics. Nevertheless parasitoid wasps are still too sparsely sampled to draw solid conclusions about whether or not their species richness follows a particular latitudinal trend, and if so, where their richness peaks.

Linking lidar and forest modeling to assess biomass estimation across scales and disturbance states

Light detection and ranging (lidar) is currently the state-of-the-art remote sensing technology for measuring the 3D structures of forests. Studies have shown that various lidar-derived metrics can be used to predict forest attributes, such as aboveground biomass. However, finding out which metric works best at which scale and under which conditions requires extensive field inventories as ground-truth data. The goal of our study was to overcome the limitations of inventory data by complementing field-derived data with virtual forest stands from a dynamic forest model. The simulated stands were used to compare 29 different lidar metrics for their utility as predictors of tropical forest biomass at different spatial scales. We used the process-based forest model FORMIND, developed a lidar simulation model, based on the Beer-Lambert law of light extinction, and applied it to a tropical forest in Panama. Simulation scenarios comprised undisturbed primary forests and stands exposed to logging and fire disturbance regimes, resulting in mosaics of different successional stages, totaling 3.7 million trees on 4200ha. The simulated forest was sampled with the lidar model. Several lidar metrics, in particular height metrics, showed good correlations with forest biomass, even for disturbed forest. Estimation errors (nRMSE) increased with decreasing spatial scale from <10% (200-m scale) to >30% (20-m scale) for the best metrics. At the often used 1-ha scale, the top-of-canopy height obtained from canopy height models with fine to relatively coarse pixel resolutions (1 to 10m) yielded the most accurate biomass predictions, with nRMSE<6% for undisturbed and nRMSE<9% for disturbed forests. This study represents the first time dynamic modeling of a tropical forest has been combined with lidar remote sensing to systematically investigate lidar-to-biomass relationships for varying lidar metrics, scales and disturbance states. In the future, this approach can be used to explore the potential of remote sensing of other forest attributes, e.g., carbon dynamics, and other remote sensing systems, e.g., spaceborne lidar and radar.

Large-area hybrid estimation of aboveground biomass in interior Alaska using airborne laser scanning data

Use of data from airborne laser scanning (ALS) is a well-established practice for enhancing the accuracy of forest inventories in combination with ground-based observations. For regular monitoring of large areas, wall-to-wall ALS data is economically prohibitive. However, when data are acquired in a strip-sampling mode, ALS can support the estimation of forest resources on large areas such as counties, states, and nations. This study investigated the combined use of ALS data acquired along parallel strips and co-located field observations of live and standing dead trees to estimate aboveground biomass (AGB) at regional and sub-regional levels. The study area comprised the Tanana Inventory Unit (TIU) (138,566km2), located in interior Alaska, and four sub-regions (106–7282km2) within the TIU. The field data consisted of 1676 ground observations from six independent field campaigns. Ninety-four plots came from the Forest Inventory and Analysis (FIA) program of the USDA Forest Service. The FIA plots, each consisting of four 1/60ha subplots, were acquired using a probabilistic sampling design. The remaining ground observations were collected during field inventories across TIU, and consisted of 335 independent field plots and 257 clusters containing up to four plots each. The estimation procedure followed a two-phase sampling design grounded within a hybrid inferential framework, which combines design-based estimation for the first phase and model-based inference in the second phase. Post-stratified estimation by land-cover class indicated that the hybrid estimation obtained 11–55% better precision compared to direct (design-based) estimation based solely on field observations. When the field sample sizes were reduced to 25%, the standard errors for the hybrid estimation increased by 3 to 5pp. Direct and hybrid estimates were compared for two sub-regions, and the hybrid estimated AGBs were 6.4% and 13.3% larger than the direct estimates. On both these study sub-regions, the 95% confidence interval of the hybrid estimated mean AGB included the direct estimate of the mean and vice versa.

Woody lianas increase in dominance and maintain compositional integrity across an Amazonian dam-induced fragmented landscape

Tropical forest fragmentation creates insular biological communities that undergo species loss and changes in community composition over time, due to area- and edge-effects. Woody lianas thrive in degraded and secondary forests, due to their competitive advantage over trees in these habitats. Lianas compete both directly and indirectly with trees, increasing tree mortality and turnover. Despite our growing understanding of liana-tree dynamics, we lack detailed knowledge of the assemblage-level responses of lianas themselves to fragmentation, particularly in evergreen tropical forests. We examine the responses of both sapling and mature liana communities to landscape-scale forest insularization induced by a mega hydroelectric dam in the Brazilian Amazon. Detailed field inventories were conducted on islands created during reservoir filling, and in nearby mainland continuous forest. We assess the relative importance of variables associated with habitat fragmentation such as area, isolation, surrounding forest cover, fire and wind disturbance, on liana community attributes including abundance, basal area, diversity, and composition. We also explore patterns of liana dominance relative to tree saplings and adults ≥10 cm diameter at breast height. We find that 1) liana community composition remains remarkably similar across mainland continuous forest and islands, regardless of extreme area- and edge- effects and the loss of vertebrate dispersers in the latter; and 2) lianas are increasing in dominance relative to trees in the sapling layer in the most degraded islands, with both the amount of forest cover surrounding islands and fire disturbance history predicting liana dominance. Our data suggest that liana communities persist intact in isolated forests, regardless of extreme area- and edge-effects; while in contrast, tree communities simultaneously show evidence of increased turnover and supressed recruitment. These processes may lead to lianas becoming a dominant component of this dam-induced fragmented landscape in the future, due to their competitive advantage over trees in degraded forest habitats. Additional loss of tree biomass and diversity brought about through competition with lianas, and the concurrent loss of carbon storage, should be accounted for in impact assessments of future dam development.

Estimation of aboveground biomass and carbon in a tropical rain forest in Gabon using remote sensing and GPS data

The knowledge of biomass stocks in tropical forests is critical for climate change and ecosystem services studies. This research was conducted in a tropical rain forest located near the city of Libreville (the capital of Gabon), in the Akanda Peninsula. The forest cover was stratified in terms of mature, secondary and mangrove forests using Landsat-ETM data. A field inventory was conducted to measure the required basic forest parameters and estimate the aboveground biomass (AGB) and carbon over the different forest classes. The Shuttle Radar Topography Mission (SRTM) data were used in combination with ground-based GPS measurements to derive forest heights. Finally, the relationships between the estimated heights and AGB were established and validated. Highest biomass stocks were found in the mature stands (223 ± 37 MgC/ha), followed by the secondary forests (116 ± 17 MgC/ha) and finally the mangrove forests (36 ± 19 MgC/ha). Strong relationships were found between AGB and forest heights (R2 > 0.85).

Temporal patterns of cotton Fusarium and Verticillium wilt in Jiangsu coastal areas of China

Cotton diseases caused by soil-borne pathogenic fungi present a major constraint to cotton production not only in China but also worldwide. A long-term field inventory was made of the prevalence of Fusarium and Verticillium wilt of cotton in the Jiangsu coastal area of China from 2000 to 2014. Various factors (crop varieties, rotation and weather) were analyzed to explore the dynamics of these diseases in cotton. The results showed that the prevalence of Fusarium and Verticillium wilt increased before 2005 and that Verticillium wilt remained at a high incidence over most of the past 10 years, while Fusarium wilt began to gradually decrease after 2005. The dynamics of Fusarium and Verticillium wilt were closely associated with the introduced cotton varieties and the intensive cropping history. In addition, weather conditions occurring during some of the years appeared to coincide with a substantial variation in the wilt diseases. Our study highlighted epidemiological dynamics of Fusarium and Verticillium wilt in a long-term survey.

PROBLEMS OF SECOND-HOME SPATIAL DEVELOPMENT IN PROTECTED AREAS. POLESIE NATIONAL PARK CASE STUDY

Purpose. To show the scale and direction of recreational housing development within an area with high natural value. Steps to ensure the sustainable development of tourist settlement are discussed. Method. GIS analysis was performed based on archival and current orthophotomaps and planning documents existing at the municipal level complemented by field inventory. Additionally, interviews with residents on PNP were employed. Findings. Four main categories of recreational housing were distinguished in the study area: compact second home estates around lakes, second home estates “attached” to villages; dispersed second homes, and old and new buildings integrated with the spatial layout of a village. The last category can be regarded as the most advantageous from an ecological, landscape and functional perspective but, unfortunately, it is the least common. The intensive development of the other categories poses a threat to the natural and tourist assets of a region. The area of recreational housing in the study area increased from 26 ha in 1992 to 156 ha in 2013, mainly in the form of separate, second-home estates. Another 169 ha have been designated for recreational housing in the current planning documents. Most of the new areas are in the immediate vicinity of the national park boundary or on lakeshores. In view of such planning arrangements, one can expect further development of the negative trends in the expansion of recreational housing and degradation of the natural and tourist assets in other areas. Research limitations and conclusions. The quantitative analysis outside PNP did not include the number of old cottages converted into recreational homes. Practical implications. The results show that greater emphasis on hierarchical planning is necessary, starting from the boundaries of the entire West Polesie Biosphere Reserve to the municipality level. The comprehensive planning of entire tourist destinations, integrating permanent and seasonal settlements and taking into account the protection of nature as well as the most valuable tourist attractions, is no less important. At the same time, more stringent limits should be imposed on dispersed housing and monofunctional tourist housing enclaves. Originality. The phenomena described coincide with trends showed by other authors but it seems that compared to other parts of Poland, the scale of negative spatial phenomenon is higher, and according to other countries the role of spatial planning in coordinating second-home development is much smaller. Type of paper. The article is a case study based on cartographic quantitative analysis.