Context-dependent plant traits drive fine-scale species persistence in old-growth forests

Questions: we studied old growth beech forest vegetation in Permanent Monitoring Plots (PMPs) located in Italy, with the following questions: is species turnover the main component of the observed changes or the present species assemblages is an impoverished sub-sets of the former ones?; 2) how compositional changes are reflected by specific plant functional traits? Location: we selected 4 PMPs (50 x 50 m) of the CONECOFOR network, placed along a latitudinal and climatic gradient in Italy, from south to north: CALABRIA03, CAMPANIA04, ABRUZZO01 and VENETO20. Methods: presence/absence of herb layer species were recorded in 100 permanent micro-plots of 50 x 50 cm over 12 years (1999-2011). For all sampled species we chose a set of 8 easy-to-measure functional traits. We compared the persistence, nestedness and turnover components of compositional changes. The role of plant traits explaining species persistence were analyzed by classification and regression tree. Results: Analysis in species diversity reveal antithetical ecological phenomena due to the diversity and complexity of the 4 different forest stands. ABRUZZO01 and CALABRIA03 show a clear nestedness trends over time with persistent species in ABR01 having higher seed mass and persistent species in CALABRIA03 having scleromorphic leaves and mesoporphic leaves, with large below-ground budbank. On the other hand, VENETO20 and CAMPANIA04 exibit a significant turnover trends over the 12 years characterized by persistent species in VENETO20 having helomorphic leaves, while in CAMPANIA04 large below-ground budbank and smaller SLA were the most important traits for species survival. Conclusion: Fine-scale approach highlight different mechanisms for the maintenance of species diversity in different complex forest systems driven significantly by specific traits, influenced by context-dependent factors

A Critical Evaluation of Remote Sensing Based Land Cover Mapping Methodologies

A novel, disaggregated approach to land cover survey is developed on the basis of land cover attributes; the parameters typically used to delineate land cover classes. The recording of land cover attributes, via objective measurement techniques, is advocated as it eliminates the requirement for surveyors to delineate and classify land cover; a process proven to be subjective and error prone. Within the North York Moors National Park, a field methodology is developed to characterise five attributes: species composition, cover, height, structure and density. The utility of land cover attributes to act as land cover ‘building blocks’ is demonstrated via classification of the field data to the Monitoring Landscape Change in the National Parks (MLCNP), National Land Use Database (NLUD) and Phase 1 Habitat Mapping (P1) schemes. Integration of the classified field data and a SPOT5 satellite image is demonstrated within per-pixel and object-orientated classification environments. Per-pixel classification produced overall accuracies of 81%, 80% and 76% at the field samples for the MLCNP, NLUD and P1 schemes, respectively. However, independent validation produced significantly lower accuracies. These decreases are demonstrated to be a function of sample fraction. Object-orientated classification, exemplified for the MLCNP schema at 3 segmentation scales, achieved accuracies approaching 75%. The aggregation of attributes to classes underutilises the potential of the remotely sensed data to describe landscape variability. Consequently, classification and geostatistical techniques capable of land cover attribute parameterisation, across the study area, are reviewed and exemplified for a sub-pixel classification. Land cover attributes provide a flexible source of field data which has been proven to support multiple land cover classification schemes and classification scales (sub-pixel, pixel and object). This multi-scaled/schemed approach enables the differential treatment of regions, within the remote sensing image, as a function of landscape characteristics and the users’ requirements providing a flexible mapping solution

Analysis of land change with parameterised multi-level class sets : exploring the semantic dimension

Een veelvoorkomend probleem in de landdynamiek is dat na verloop van tijd kennis vordert, technologie ontwikkelt en beleidsdoelstellingen veranderen. Dit betekent dat met elke kartering die wordt uitgevoerd, met een voor dat doel specifiek ontworpen classificatie, een nieuwe basis dataset wordt gemaakt in plaats van een continue gegevensreeks. Verschillen in de naamgeving van klassen, veranderingen in de definitie van de klasse, en de toevoeging of verwijdering van de klassen in de datasets over hetzelfde gebied in verschillende periodes leveren problemen op in de scheiding van de feitelijke veranderingen in de tijd van klaarblijkelijke veranderingen in de definities van categorieën. In de praktijk zullen de resultaten van verschillende onderzoeken echter moeten worden geharmoniseerd in tijd en ruimte

Monitoring Large Conservation Areas with Imaging Spectroscopy

Monitoring of large conservation areas has to be accomplished to fulfil the reporting commitment of the European FFH Directive. Aim of this project was to develop a new monitoring approach for area-wide mapping on a stand level. This approach was based on the combination of numerical methods in vegetation ecology with imaging spectroscopy. The study took place in the FFH conservation area Murnauer Moos, Upper Bavaria. The imagery had been gathered using the imaging spectrometer HyMap™. In order to develop maps that include spatial information on vegetation types as well as on transitions, crisp field and image classifications were combined with fuzzy methods in field and image data analysis. With Non-metric Multidimensional Scaling (NMS) ordination technique for the pre-processing of vegetation data and Partial Least Squares (PLS) regression for extrapolation, we took account of occurring mixed stands and gradual vegetation transitions. In contrast, crisp supervised image classifications are suited to assign clear categories, which are also needed in management practice. Certain emphasis was given to the different possibilities of ground data classification and endmember selection. Different applications of endmember determination to Spectral Angle Mapper (SAM) classification and Multiple Endmember Spectral Mixture Analysis (MESMA) were compared. Synthesis maps for monitoring were produced that deliver two-fold information on pixel basis: vegetation type membership on the one side, stand position in the context of the continuous field of the vegetation on the other. Hence, ecotones can be monitored within habitats. This study shows that with the use of high spatial and spectral resolution of the imagery, this information is given in the same spatial detail for a large area, and the quality of the given details is measurable

Distribution patterns and habitat use of black cockatoos (Calyptorhynchus spp.) in modified landscapes in the south-west of Western Australia

Conservation planning for animal species inhabiting modified landscapes requires understanding of where animals occur and how they utilise both natural and modified habitats. In this study the distribution and foraging behaviour of the forest red-tailed cockatoo (Calyptorhynchus banksii naso), Baudin’s cockatoo (C. baudinii) and Carnaby’s cockatoo (C. latirostris) was investigated in three study areas which each contained a different combination of modified habitats. Pickering Brook contained native forest and orchards, Wungong contained a mosaic of native forest and revegetation, while Karnet contained primarily native forest and paddocks. The relationship between cockatoo distribution and land use types was examined by constructing Generalised Linear Models based on bird counts and land use data along 90.5 km of road transects. The Akaike Information Criterion (AIC) was used to select a set of the most parsimonious candidate models. Models were constructed at two scales: Regional models incorporated the datasets of all three study areas, while study area models used the datasets of single study areas. Models for the forest red-tailed cockatoo indicated selection against young post-1988 revegetation. This response was apparent at both the regional scale and within the Wungong study area. Baudin’s cockatoo selected in favour of orchards at the regional scale, but their distribution was unrelated to any land use variable within the (orchard-rich) Pickering Brook study area. No models were constructed for Carnaby’s cockatoo due to a limited number of observations for this species. Feeding observations demonstrated the importance of the native eucalypts marri (Corymbia calophylla) and jarrah (Eucalyptus marginata) as a food source for the forest red-tailed cockatoo and Baudin’s cockatoo. In contrast Carnaby’s cockatoo fed most frequently in plantations of introduced pine (Pinus spp.). Contrary to model predictions, Baudin’s cockatoo was never observed feeding in apple orchards during the study. This discrepancy may be due to timing of the surveys outside the hours when Baudin’s cockatoo fed in orchards, or it could indicate that orchards are of limited importance as a food source. Forest red-tailed cockatoos consistently fed on particular marri trees while ignoring others, but this selectivity was unrelated to fruit morphology or seed nutrient content. Instead, foraging patterns may have been driven by ingrained habits, or by variation in the concentration of secondary compounds. iv In conservation efforts, identification of critical habitats is an important first step. This study highlighted the importance of studying habitat selection and constructing management plans at an appropriate scale, relative to the range of the target species. Wide ranging species like black cockatoos require regional scale protection of important broad vegetation types such as the northern jarrah forest, combined with landscape scale protection and restoration – for instance during postmining revegetation – of specific feeding habitat and food species, such as pine for Carnaby’s cockatoo and possibly Fraser’s sheoak (Allocasuarina fraseriana) for the forest red-tailed cockatoo

Métodos alternativos de muestreo para estimar la estructura y caracteres reproductivos de bosques

Aleppo pine had a large forest cover in North Africa and along the Mediterranean basin which management is not fully developed and new forest tools are required. In this research, the forest structure, epidometric characteristics and allometric relationships were studied in 79 plots covering four bioclimatic zones from natural even aged forests of Aleppo pine located between eastern Algeria to the western coastal part of Tunisia. To characterize the forest structure three sampling methods were carried out: classical inventories (recording all pine trees), and two simplified approach using one average size or five dominant pine tree per plot. Annual growth increment and cone production were only calculated for the average size tree. Furthermore, the analysis of variance showed non-significant differences recorded between bioclimatic zones in trunk or crown diameter using the two simplified approach. Moreover, a significant decrease from wetter to drier areas in total height, crown height, cone seed production was observed only for average size tree method. However, the analysis of covariance showed significant differences between both approaches in total height, trunk diameter and crown coverage which were largely influenced by the pine tree density. In future investigations, we confirmed previous research that the dominant tree is a good sampling method to examine the site fertility, whereas the average size tree constitutes a valuable approach to study the population growth and reproduction.El pino carrasco muestra una gran cobertura forestal, tanto en el norte de África como en toda la Cuenca Mediterránea, cuyo manejo no está totalmente desarrollado lo que requiere nuevas herramientas de manejo. En esta investigación, se estudiaron la estructura forestal, las características epidométricas y las relaciones alométricas de 79 parcelas distribuidas a lo largo de cuatro zonas bioclimáticas en bosques regulares de pino carrasco situados entre el este de Argelia y la costa este de Túnez. Para caracterizar la estructura forestal se aplicaron tres métodos de muestreo: inventario clásico (midiendo todos los pies) y dos propuestas más sencillas, usando un árbol medio o cinco pies dominantes por parcela. El análisis de varianza no mostraba diferencias significativas de las mediciones de diámetro de tronco y de copa realizadas entre las distintas zonas bioclimáticas usando ambos métodos. Por otra parte, se observó una disminución significativa de las zonas más húmedas a las más secas en altura toral, altura de copa y producción de semillas fue observada aplicando el método de árbol medio. Además, el análisis de covarianzas mostraba diferencias significativas, usando ambas metodologías, en los valores medios de altura total, diámetro de tronco y cobertura de copa que mostraron estar influenciados por los valores de la densidad de arbolado de cada zona. Para futuras investigaciones, confirmamos estudios previos que apuntaban que la propuesta de muestreo de árboles dominantes como un buen método de muestreo para caracterizar la calidad de sitio mientras que la de árbol medio constituye una valiosa propuesta para el estudio del crecimiento de poblaciones y sus características reproductivas

Sand Dune Systems in Iran - Distribution and Activity.

Wind erosion and shifting sand dunes as a land degradation process is a serious problem in Iran. There are significant gaps in our knowledge of Iran sand dunes in national scale for the English speaking international scientific community as well as wind erosion and sand transport in Sistan plain. Identifying active dunes and monitoring areas with migrating sand are important prerequisites for mitigating these damages. In addition, wind erosion is one of the most serious problems in the Sistan region, located in the East of Iran and near the border of Afghanistan. This thesis has two major purposes: (1) to assess sand dune activity in national scale of Iran (2) to investigate wind regime and investigated spatial and temporal patterns of wind erosion process in Sistan region. With regard to first objective, the spatial variation of the wind energy environment based on the sand drift potential (DP), with using Fryberger and Dean's (1979) method, was calculated from 204 meteorological stations in and around Iran’s deserts. Three commonly dune activity models – the Lancaster mobility index (1988), the Tsoar mobility index (2005), and the index developed by Yizhaq et al. (2009) – were used for the evaluation of Iran’s sand dune activity. The analysis of the indices showed that the dunes activity was characterized by great spatial variations across Iran’s deserts. All three models identified fully active dunes in the Sistan plain, the whole of the Lut desert, as well as in the Zirkuh Qaien and Deyhook regions, while the dunes in the northern part of Rig Boland, Booshroyeh and in the Neyshabor dunefields were categorized as stabilized dunes. For other dunes, the models show a less unified activity classification, with the Lancaster and Yizhaq models having more similar results while the Tsoar model stands more apart. Overall the three models delivered comparable results in some instances and diverging results in others. The reasons for this are the use of different parameters and their impact on the model construction. The main contradictions of the three models results are revealed when the wind blows for only short times but with a high energy, like in the north of the Dasht-e Kavir desert (Damagan, Foromad) and at some stations in the wind of the 120 days’ domain (Sedeh Birjand). Field observation demonstrated that dunes in these areas are completely active, but the Lancaster mobility index (LMI) classified them as inactive or semi-active because of a low to moderate percentage of wind events above the transport threshold. At the same time the DP in this region showed high values and thus the Tsoar mobility index (TMI) classified the dunes as active, while the Yizhaq model (YMI) classified them as active or semi-active. In fact, in spite of high wind energy, the percentage of winds above threshold (W%), that is upper 12 knot or 6.2 m s-1 in this study, was rather low, as high speed winds only occur during the warm season, while the rest of the year is characterized by calm weather. The nature of the wind power parameter varies from the LMI, that is the percentage of winds above threshold (W%) to the TMI and YMI that is DP. DP reflects the quantity (frequency) and quality (intensity) of the wind power, but W% only shows its quantity (frequency of winds above the transport threshold). It seems that if DP was used in the LMI instead of W%, it would provide more favourable results . In addition, the statistical analysis (correlation coefficient) between DP values and the percentage of wind events above the transport threshold (%W) at the meteorological stations in the study area shows a moderate correlation. Based on this argumentation, W% has been replaced by the DP (vu) as the wind energy parameter in Lancaster mobility index (1988) and a Modified Lancaster Index (MLI) was developed. Based on these model results and fields observations, a modified Lancaster mobility index has been applied to show a more realistic spatial variation of sand dunes activity in Iran’s desert areas. With regard to second objective, the wind regime, formation of aeolian dunes and the rate of sand transport in Sistan and Registan were investigated. The Sistan region in eastern Iran and the Registan region in South-western Afghanistan are strongly influenced by the Sadobist Roozeh wind (the wind of the 120 days), which is blowing along the Iran-Afghanistan border from North to South, then shifts it’s direction toward the Southeast into the Sistan region and, finally, continues eastward into south-western Afghanistan, forming the Registan sand seas. It blows during the hot season due to the pressure gradient between the Turkmenistan High and the Pakistan Low. In order to determine the wind regime and the sand transport, wind roses based on long-term datasets from 16 meteorological stations, DP, the Resultant Drift Direction (RDD), the Resultant Drift Potential (RDP) and the RDP/DP ratio have been calculated using Fryberger and Dean's (1979) method. The distribution of the Registan sand dunes was surveyed by using Landsat ETM data, Google Earth scenes and field operations (the latter only in the Iranian part). The spatial differences of the drift potential were simulated using GIS and geostatistical methods overlaying the sand dune map. The results show that DP increases from north to south along the border between Iran and Afghanistan and reaches to highest values in the Sistan region, then decreases gradually in the Registan sand seas. The highest wind energy, based on DP matches, was determined exactly where the ephemeral lakes in the northern part of the Sistan plain are located, which function as a source area of intense dust and sand storms during the dry season. The annual DP calculated in Sistan is one of the highest values (2516 vector units) in inland desert and categorized it into the windiest desert in the world. The temporal trend of the DP showed an increase between 1999 and 2007, followed by a decrease until 2015 in Sistan. The results show that the wind regime in the Sistan and Registan regions is unimodal during the wind of 120 days (the Sadobist Roozeh) period, which is also supported by the dominance of transverse, barchanoid and barchans dunes in both regions . In continue second objective, we measured the rate of sediment transport in Hamoun-e Baringak, as one of the six ephemeral lakes, producing more aeolian sediment into the atmosphere in Sistan region. In order to investigate the land surface sensitivity to aeolian transport, 74 graduated pins were embedded randomly in the ephemeral Baringak Lake bed and the aeolian transport rates were measured for three events in 2013 individually as well as for the total study period. The spatial and temporal variation of the aeolian transport was also mapped using GIS and geostatistics methods for these events and for the total duration of 103 days. The resulting variogram revealed a high spatial dependence of the different events and showed that geostatistical techniques are a valid tool for the mapping of aeolian sediment transport. The average transport rate in terms of the detected drift height on the dry lake bed was 1.93 cm or 31 kg/m2 between the 5th of August and the 17th of November in 2013

A regional land use survey based on remote sensing and other data: A report on a LANDSAT and computer mapping project, volume 2

The author has identified the following significant results. The project mapped land use/cover classifications from LANDSAT computer compatible tape data and combined those results with other multisource data via computer mapping/compositing techniques to analyze various land use planning/natural resource management problems. Data were analyzed on 1:24,000 scale maps at 1.1 acre resolution. LANDSAT analysis software and linkages with other computer mapping software were developed. Significant results were also achieved in training, communication, and identification of needs for developing the LANDSAT/computer mapping technologies into operational tools for use by decision makers