Status and conservation needs of Cycas pectinata Buch.-Ham. in its natural habitat at Baroiyadhala National Park, Bangladesh

The widespread cycad Cycas pectinata was first discovered in the Bengal region by William Griffith in Baroiyadhala forest of Chattogram in 1838. In Bangladesh, this species is confined to a few hills at Baroiyadhala, Sitakunda upazila of Chattogram district. Though the Baroiyadhala forests were declared a national park in 2010, the loss of this native gymnosperm from this forest is alarming. The present study aimed to assess the status of C. pectinata populations in its native range, identify the drivers responsible for ongoing losses, and identify locations of C. pectinata occurrence in Baroiyadhala National Park suitable for in situ conservation. A random quadrat survey with 21 sample plots of 100 × 100 m was conducted during April–June 2018 in Baroiyadhala National Park. Population and growth data for C. pectinata were collected from each sample plot, along with observations of disturbances. Four focus group discussions (FGDs) were conducted with adjacent local people. The study revealed presence of 12 C. pectinata individuals per hectare and five seedlings per hectare in the study area, and significant numbers of dead and burned Cycas were also found in some sites. Based on density, five C. pectinata hotspots were identified for in situ conservation programs. Habitat destruction, indiscriminate fire, and unsustainable harvesting of leaves and male and female cones are responsible for rapid declines in C. pectinata populations in its wild habitat. Measures for protection and restoration of the species are creating awareness among the local people about ecological importance of this species; enhancing protection; banning trade of Cycas; creating opportunities of sustainable livelihood for local people to reduce dependency on forests.

Distribution Pattern and Phytosociological study of Trees Associated with Agroforestry in Poonch District of Jammu and Kashmir, India

The focus of present study was to find the phytosociology, distribution pattern, and diversity of different species of trees associated with traditional agroforestry in the district of Poonch, Jammu and Kashmir, India. Data was collected through quadrat survey method. A total of fifty quadrats of the size (10x10m) each were thrown randomly in agriculture fields. Total 26 tree species belonging to 16 families and 21 genera were encountered in the agricultural fields with Grewia optiva, Pyrus persica and Celtis australis being the tree species in dominance. The most dense species of tree recorded was Grewia optiva with a density value of 3.88 tree/ha which was followed by Pyrus persica with a density of 3.74 tree/ha. Buxus wallichiana was the least dense species recorded (0.82 tree/ha). The study revealed that the area has vast potential sites for the plantation of various agroforestry related tree species to solve the problems of fuel, fodder and timber.

Ecological Relationship between Vascular Plants and Crusts after Sand Fixation Project in Desert

In order to understand more about the relationship between vascular plants and crusts after the biological sand fixation project, the vascular plants, composition, coverage and composition changes of crusts in artificial sand fixation vegetation area in Shapotou are studied by quadrat survey method. It is found that the height and coverage of shrubs will decrease with the increase of years after the sand fixation project until reaching a balanced state. The number and height of herbaceous plants will increase in the same period of time, and the thickness of crusts will also increase continuously. According to the water storage property of crusts, when the number of years increases, the thicker the crusts are, the more shrubs will be provided with growth conditions. In addition, shrub roots directly affect biological sand fixation ability, so this paper studies the ecological relationship between vascular plants and crusts after the desert sand fixation project, providing reference for more effective sand fixation work.

Evaluation of the Accuracy of the Field Quadrat Survey of Alpine Grassland Fractional Vegetation Cover Based on the Satellite Remote Sensing Pixel Scale

The fractional vegetation cover (FVC) data measured on the ground is the main source for the calibration and verification of FVC remote sensing inversion, and its accuracy directly affects the accuracy of remote sensing inversion results. However, the existing research on the evaluation of the accuracy of the field quadrat survey of FVC based on the satellite remote sensing pixel scale is inadequate, especially in the alpine grassland of the Qinghai-Tibet Plateau. In this paper, five different alpine grasslands were examined, the accuracy of the FVC obtained by the photography method was analyzed, and the influence of the number of samples on the field survey results was studied. First, the results show that the threshold method could accurately extract the vegetation information in the photos and obtain the FVC with high accuracy and little subjective interference. Second, the number of samples measured on the ground was logarithmically related to the accuracy of the FVC of the sample plot (p < 0.001). When the number of samples was larger, the accuracy of the FVC of the sample plot was higher and closer to the real value, and the stability of data also increased with the increase of the number of samples. Third, the average FVC of the measured quadrats on the ground was able to represent the FVC of the sample plot, but on the basis that there were enough measured quadrats. Finally, the results revealed that the degree of fragmentation reflecting the state of ground vegetation affects the acquisition accuracy of FVC. When the degree of fragmentation of the sample plot is higher, the number of samples needed to achieve the accuracy index is higher. Our results suggest that when obtaining the FVC on the satellite remote sensing pixel scale, the number of samples measured on the ground is an important factor affecting the accuracy, which cannot be ignored.

Organic amendment increases arbuscular mycorrhizal fungal diversity in primary coastal dunes

Plastic pots were inserted beneath seedlings of a shallow-rooted C4grass species, Ischaemum indicum, with and without a root-impenetrable nylon sachet filled with organic matter (OM) amendment, at seven stations along an interrupted belt transect in which plant community and soil chemistry had been previously surveyed. The transect was perpendicular to mean high-water mark (MH-WM) across a primary coastal dune system in Goa, India, where summer monsoon is the predominant weather feature. The Quadrat survey of plant frequency was made in stations when the above-ground biomass was estimated to be highest. Arbuscular mycorrhiza fungal (AMF) spore density and diversity were determined morphologically in amended and control pots soils, and in OM sachet residues, after host-plant desiccation when monsoon rains had ceased. Twenty-seven AM fungal spore morphotypes were isolated from the pots containing OM amended rhizosphere soils, 19 from controls and 14 from OM residues in the sachets. Gigaspora margarita proved to be the dominant spore in all treatments. Eight morphotypes recovered from amended pots were not recovered from the controls. There was an increasing trend in species diversity in amended pots away from MH-WM. Spore recovery from the three regimes showed variable distribution that indicated differing AMF species strategies.

Primary sand-dune plant community and soil properties during the west-coast India monsoon

A seven-station interrupted belt transect was established that followed a previously observed plant zonation pattern across an aggrading primary coastal dune system in the dry tropical region of west-coast India. The dominant weather pattern is monsoon from June to November, followed by hot and dry winter months when rainfall is scarce. Physical and chemical soil characteristics in each of the stations were analysed on five separate occasions, the first before the onset of monsoon, three during and the last post-monsoon. The plant community pattern was confirmed by quadrat survey. A pH gradient decreased with distance from the shoreline. Nutrient concentrations were deficient, increasing only in small amounts until the furthest station inland. At that location, there was a distinct and abrupt pedological transition zone from psammite to humic soils. There was a significant increase over previous stations in mean organic matter, ammonium nitrate and soil-water retention, although the increase in real terms was small. ANOVA showed significant variation in electrical conductivity, phosphorus, calcium, magnesium and sodium concentrations over time. There was no relationship between soil chemistry characteristics and plant community structure over the transect. Ipomoea pes-caprae and Spinifex littoreus were restricted to the foredunes, the leguminous forb Alysicarpus vaginalis and Perotis indica to the two stations furthest from the strand. Ischaemum indicum, a C4 perennial grass species adopting an ephemeral strategy was, in contrast, ubiquitous to all stations.

Analysis on Forestry-Paper Integration of Raw Material Forest Base of Posterior Ecological Impact Assessment

Forest-paper integration has lots of effect on ecological environment , mainly including biodiversity, soil erosion, soil quality and non-point pollution，the paper takes bamboo raw material forest base of He Jiang and Na Xi in province Si Chuan as a research，analyzes Plant Diversity by quadrat survey procedure，analyzes land use pattern by remote sense technique，and analyzes physical properties of soil，presents study direction on the forestry-paper integration of raw material forest base.

Vegetation patterns in permanent spring wetlands in arid Australia

A transect-based quadrat survey was conducted within 11 spring wetlands fed by permanent groundwater flows from the Great Artesian Basin at Elizabeth Springs in western Queensland. Flow patterns within individual wetlands change with sedimentation associated with mound building, siltation of abandoned drains and changes in aquifer pressure associated with artificial extraction from bores. The pattern of floristic groups for the wetland quadrats was poorly related to soil texture, water pH, slope and topographic position. Patterns were most clearly related to wetland age as determined from aerial photography, with a clear successional sequence from mono-specific stands of Cyperus laevigatus on newly formed wetland areas to more diverse wetland assemblages. However, evidence from other Great Artesian Basin springs suggests that succession can also result in reduced species richness where the palatable tall reed Phragmites australis develops mono-specific stands.