scholarly journals Stretching the Habitat Envelope: Insectivorous Bat Guilds Can Use Rubber Plantations, but Need Understorey Vegetation and Forest Buffers

2021 ◽  
Vol 2 ◽  
Author(s):  
Kadambari Deshpande ◽  
Nachiket Kelkar ◽  
Jagdish Krishnaswamy ◽  
Mahesh Sankaran
Keyword(s):  
Land Cover ◽  
Management Practices ◽  
Forest Cover ◽  
Foraging Strategies ◽  
Insectivorous Bats ◽  
Understorey Vegetation ◽  
Land Cover Types ◽  
Rubber Plantations ◽  
Bat Activity ◽  
Western Ghats Of India

Effects of land-cover change on insectivorous bat activity can be negative, neutral or positive, depending on foraging strategies of bats. In tropical agroforestry systems with high bat diversity, these effects can be complex to assess. We investigated foraging habitat use by three insectivorous bat guilds in forests and rubber plantations in the southern Western Ghats of India. Specifically, we monitored acoustic activity of bats in relation to (1) land-cover types and vegetation structure, and (2) plantation management practices. We hypothesized that activity of open-space aerial (OSA) and edge-space aerial (ESA) bat guilds would not differ; but narrow-space, flutter-detecting (NSFD) bat guild activity would be higher, in structurally heterogeneous forest habitats than monoculture rubber plantations. We found that bat activity of all guilds was highest in areas with high forest cover and lowest in rubber plantations. Higher bat activity was associated with understorey vegetation in forests and plantations, which was expected for NSFD bats, but was a surprise finding for OSA and ESA bats. Within land-cover types, open areas and edge-habitats had higher OSA and ESA activity respectively, while NSFD bats completely avoided open habitats. In terms of management practices, intensively managed rubber plantations with regular removal of understorey vegetation had the lowest bat activity for all guilds. Intensive management can undermine potential ecosystem services of insectivorous bats (e.g., insect pest-control in rubber plantations and surrounding agro-ecosystems), and magnify threats to bats from human disturbances. Low-intensity management and maintenance of forest buffers around plantations can enable persistence of insectivorous bats in tropical forest-plantation landscapes.

scholarly journals Identifying Establishment Year and Pre-Conversion Land Cover of Rubber Plantations on Hainan Island, China Using Landsat Data during 1987–2015

2018 ◽  
Vol 10 (8) ◽  
pp. 1240 ◽  
Author(s):  
Bangqian Chen ◽  
Xiangming Xiao ◽  
Zhixiang Wu ◽  
Tin Yun ◽  
Weili Kou ◽  
...  
Keyword(s):  
Land Cover ◽  
Best Management Practices ◽  
Management Practices ◽  
Rubber Tree ◽  
Hainan Island ◽  
Stand Age ◽  
Rubber Plantation ◽  
Land Cover Types ◽  
Rubber Plantations ◽  
Evergreen Forests

Knowing the stand age of rubber tree (Hevea brasiliensis) plantations is vitally important for best management practices, estimations of rubber latex yields, and carbon cycle studies (e.g., biomass, carbon pools, and fluxes). However, the stand age (as estimated from the establishment year of rubber plantation) is not available across large regions. In this study, we analyzed Landsat time series images from 1987–2015 and developed algorithms to identify (1) the establishment year of rubber plantations; and (2) the pre-conversion land cover types, such as old rubber plantations, evergreen forests, and cropland. Exposed soil during plantation establishment and linear increases in canopy closure during non-production periods (rubber seedling to mature plantation) were used to identify the establishment year of rubber plantations. Based on the rubber plantation map for 2015 (overall accuracy = 97%), and 1981 Landsat images since 1987, we mapped the establishment year of rubber plantations on Hainan Island (R2 = 0.85/0.99, and RMSE = 2.34/0.54 years at pixel/plantation scale). The results show that: (1) significant conversion of croplands and old rubber plantations to new rubber plantations has occurred substantially in the northwest and northern regions of Hainan Island since 2000, while old rubber plantations were mainly distributed in the southeastern inland strip; (2) the pattern of rubber plantation expansion since 1987 consisted of fragmented plantations from smallholders, and there was no tendency to expand towards a higher altitude and steep slope regions; (3) the largest land source for new rubber plantations since 1988 was old rubber plantations (1.26 × 105 ha), followed by cropland (0.95 × 105 ha), and evergreen forests (0.68 × 105 ha). The resultant algorithms and maps of establishment year and pre-conversion land cover types are likely to be useful in plantation management, and ecological assessments of rubber plantation expansion in China.

Remote sensing and GIS forest landscape assessment for sustainable forest management

2021 ◽  
Vol 17 (1) ◽  
pp. 12-26
Author(s):  
A.F. Chukwuka ◽  
A. Alo ◽  
O.J. Aigbokhan
Keyword(s):  
Remote Sensing ◽  
Land Cover ◽  
Forest Cover ◽  
Sustainable Forest Management ◽  
Markov Chain Model ◽  
Remote Sensing Data ◽  
Chain Model ◽  
Spatial Metrics ◽  
Forest Reserve ◽  
Land Cover Types

This study set out to assess the dynamic characteristics of the Ikere forest reserve landscape between 1985 and 2017 using remote sensing data and spatial metrics. Landscape of the study area maintained complex patterns of spatial heterogeneity over the years. Forest cover loss to other land cover types results in new large non-forest area at increasing rate. As at the year 2017, the changes in land cover types were not yet at equilibrium, thus the need to determine the future forest cover extent using a three-way markov Chain model. The decrease in number of patches of forest land (NumP) with increase in its mean patch size (MPS) shows that the forest is becoming a single unit probably due to clearing of existing patches of forest trees. The decrease in class diversity and evenness (SDI and SEI) of the general landscape over the years strengthens this assertion. The findings of this study would be very helpful to government and other stakeholders responsible for ensuring sustainable forest and general environment. Keyword: Landscape, Spatial metrics, sustainable forest and Environment

Monitoring post-fire vegetation recovery in the Mediterranean using SPOT and ERS imagery

2014 ◽  
Vol 23 (5) ◽  
pp. 631 ◽  
Author(s):  
A. Polychronaki ◽  
I. Z. Gitas ◽  
A. Minchella
Keyword(s):  
Land Cover ◽  
Forest Regeneration ◽  
Vegetation Index ◽  
Backscatter Coefficient ◽  
Understorey Vegetation ◽  
Regeneration Rate ◽  
Land Cover Types ◽  
Normalised Difference Vegetation Index ◽  
Forested Areas ◽  
The Mediterranean

This study examined the effect of two different forest fires 19 and 23 years ago on the Mediterranean island of Thasos. An object-based classification scheme was developed to map the major land-cover types using multi-temporal Système Pour l’Observation de la Terre (SPOT) and European Remote-Sensing (ERS) (C-band VV) images covering the time period from 1993 to 2007. The developed scheme mapped the post-fire land-cover types accurately: 0.84 Kappa coefficient and 90.5% overall accuracy. The use of the ERS backscatter coefficient contributed to decreasing the commission errors related to the mapping of forested areas and to overcoming misclassifications that occurred between forested areas and shrublands located in shadowed areas. Results indicated that the forest regeneration rate is rather slow, especially in areas where the degree of burn severity was high while the largest part of the burned area is, to date, covered by low vegetation and shrubs. Nevertheless, a gradual shift from low vegetation to shrubland was observed. A preliminary investigation on the use of the ERS backscatter coefficient and the Normalised Difference Vegetation Index to monitor forest regeneration revealed that the backscatter coefficient could provide information related to changes in dense regenerating pine forests for the first 18 years after the fire event, whereas the Normalised Difference Vegetation Index was found to be sensitive to the regenerating forest understorey vegetation. However, further investigation is needed to confirm these findings.

Reach-scale effects of riparian forest cover on urban stream ecosystems

2005 ◽  
Vol 62 (10) ◽  
pp. 2312-2329 ◽  
Author(s):  
Allison H Roy ◽  
Christina L Faust ◽  
Mary C Freeman ◽  
Judith L Meyer
Keyword(s):  
Land Cover ◽  
Management Practices ◽  
Forest Cover ◽  
Scale Effects ◽  
Riparian Forest ◽  
Canopy Cover ◽  
Habitat Diversity ◽  
Urban Stream ◽  
Ecosystem Integrity ◽  
Small Streams

We compared habitat and biota between paired open and forested reaches within five small streams (basin area 10–20 km2) in suburban catchments (9%–49% urban land cover) in the Piedmont of Georgia, USA. Stream reaches with open canopies were narrower than forested reaches (4.1 versus 5.0 m, respectively). There were no differences in habitat diversity (variation in velocity, depth, or bed particle size) between open and forested reaches. However, absence of local forest cover corresponded to decreased large wood and increased algal chlorophyll a standing crop biomass. These differences in basal food resources translated into higher densities of fishes in open (9.0 individuals·m–2) versus forested (4.9 individuals·m–2) reaches, primarily attributed to higher densities of the herbivore Campostoma oligolepis. Densities of terrestrial invertebrate inputs were higher in open reaches; however, trends suggested higher biomass of terrestrial inputs in forested reaches and a corresponding higher density of terrestrial prey consumed by water column feeding fishes. Reach-scale biotic integrity (macroinvertebrates, salamanders, and fishes) was largely unaffected by differences in canopy cover. In urbanizing areas where catchment land cover drives habitat and biotic quality, management practices that rely exclusively on forested riparian areas for stream protection are unlikely to be effective at maintaining ecosystem integrity.

scholarly journals The Return of Nature to the Chernobyl Exclusion Zone: Increases in Forest Cover of 1.5 Times since the 1986 Disaster

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1024
Author(s):  
Maksym Matsala ◽  
Andrii Bilous ◽  
Viktor Myroniuk ◽  
Dmytrii Holiaka ◽  
Dmitry Schepaschenko ◽  
...  
Keyword(s):  
Land Cover ◽  
Management Practices ◽  
Forest Cover ◽  
Natural Disturbance ◽  
Training Data ◽  
Classification Model ◽  
Ecosystem Functions ◽  
Exclusion Zone ◽  
Temporal Segmentation ◽  
Random Forest Classification

For 34 years since the 1986 nuclear disaster, the Chernobyl Exclusion Zone (ChEZ) landscapes have been protected with very limited human interventions. Natural afforestation has largely occurred throughout the abandoned farmlands, while natural disturbance regimes, which dominantly include wildfires, have become more frequent and severe in the last years. Here, we utilize the dense time series of Landsat satellite imagery (1986–2020) processed by using the temporal segmentation algorithm LandTrendr in order to derive a robust land cover and forest mask product for the ChEZ. Additionally, we carried out an analysis of land cover transitions on the former farmlands. The Random Forest classification model developed here has achieved overall accuracies of 80% (using training data for 2017) and 89% on a binary “forest/non-forest” validation (using data from 1988). The total forest cover area within the ChEZ has increased from 41% (in 1986) to 59% (in 2020). This forest gain can be explained by the afforestation that has occurred in abandoned farmlands, which compensates for forest cover losses due to large fire events in 1992, 2015–2016, and 2020. Most transitions from open landscapes to dense forest cover occurred after the year 2000 and are possibly linked to past forest management practices. We conclude that a consistent forest strategy, with the aid of remote monitoring, is required to efficiently manage new forests in the ChEZ in order to retain their ecosystem functions and to ensure sustainable habitats.

scholarly journals Comparison of field and airborne laser scanning based crown cover estimates across land cover types in Kenya

2015 ◽  
Vol XL-7/W3 ◽  
pp. 409-415 ◽  
Author(s):  
J. Heiskanen ◽  
L. Korhonen ◽  
J. Hietanen ◽  
V. Heikinheimo ◽  
E. Schäfer ◽  
...  
Keyword(s):  
Land Cover ◽  
Laser Scanning ◽  
Field Data ◽  
Forest Cover ◽  
Practical Method ◽  
Airborne Laser Scanning ◽  
Data Sets ◽  
Land Cover Types ◽  
Crown Cover ◽  
Airborne Laser

Tree crown cover (CC) provides means for the continuous land cover characterization of complex tropical landscapes with multiple land uses and variable degrees of degradation. It is also a key parameter in the international forest definitions that are basis for monitoring global forest cover changes. Recently, airborne laser scanning (ALS) has emerged as a practical method for accurate CC mapping, but ALS derived CC estimates have rarely been assessed with field data in the tropics. Here, our objective was to compare the various field and ALS based CC estimates across multiple land cover types in the Taita Hills, Kenya. The field data was measured from a total of 178 sample plots (0.1 ha) in 2013 and 2014. The most accurate field measurement method, line intersect sampling using Cajanus tube, was used in 37 plots. Other methods included CC estimate based on the tree inventory data (144 plots), crown relascope (43 plots) and hemispherical photography (30 plots). Three ALS data sets, including two scanners and flying heights, were acquired concurrently with the field data collection. According to the results, the first echo cover index (FCI) from ALS data had good agreement with the most accurate field based CC estimates (RMSD 7.1% and 2.7% depending on the area and scan). The agreement with other field based methods was considerably worse. Furthermore, we observed that ALS cover indices were robust between the different scans in the overlapping area. In conclusion, our results suggest that ALS provides a reliable method for continuous CC mapping across tropical land cover types although dense shrub layer and tree-like herbaceous plants can cause overestimation of CC.

scholarly journals Effects of Land Cover Changes on Net Primary Productivity in the Terrestrial Ecosystems of China from 2001 to 2012

Land ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 480
Author(s):  
Hanwei Li ◽  
Juhua Ding ◽  
Jiang Zhang ◽  
Zhenan Yang ◽  
Bin Yang ◽  
...  
Keyword(s):  
Land Cover ◽  
Land Cover Change ◽  
Primary Productivity ◽  
Forest Cover ◽  
Net Primary Productivity ◽  
Terrestrial Ecosystems ◽  
Land Cover Types ◽  
Cropland Area ◽  
Land Cover Data ◽  
Increasing Trends

The 2001–2012 MODIS MCD12Q1 land cover data and MOD17A3 NPP data were used to calculate changes in land cover in China and annual changes in net primary productivity (NPP) during a 12-year period and to quantitatively analyze the effects of land cover change on the NPP of China’s terrestrial ecosystems. The results revealed that during the study period, no changes in land cover type occurred in 7447.31 thousand km2 of China, while the area of vegetation cover increased by 160.97 thousand km2 in the rest of the country. Forest cover increased to 20.91%, which was mainly due to the conversion of large areas of savanna (345.19 thousand km2) and cropland (178.96 thousand km2) to forest. During the 12-year study period, the annual mean NPP of China was 2.70 PgC and increased by 0.25 PgC, from 2.50 to 2.75 PgC. Of this change, 0.21 PgC occurred in areas where there was no land cover change, while 0.04 PgC occurred in areas where there was land cover change. The contributions of forest and cropland to NPP exhibited increasing trends, while the contributions of shrubland and grassland to NPP decreased. Among these land cover types, the contributions of forest and cropland to the national NPP were the greatest, accounting for 40.97% and 27.95%, respectively, of the annual total NPP. There was no significant correlation between changes in forest area and changes in total annual NPP (R2 < 0.1), while the correlation coefficient for changes in cropland area and total annual NPP was 0.48. Additionally, the area of cropland converted to other land cover types was negatively correlated with the changes in NPP, and the loss of cropland caused a reduction in the national NPP.

scholarly journals Mapping Annual Forest Change Due to Afforestation in Guangdong Province of China Using Active and Passive Remote Sensing Data

2019 ◽  
Vol 11 (5) ◽  
pp. 490 ◽  
Author(s):  
Wenjuan Shen ◽  
Mingshi Li ◽  
Chengquan Huang ◽  
Xin Tao ◽  
Shu Li ◽  
...  
Keyword(s):  
Land Cover ◽  
Vegetation Index ◽  
Forest Cover ◽  
Southern China ◽  
Carbon Accounting ◽  
Gradient Boosting ◽  
Forest Cover Change ◽  
Land Cover Types ◽  
Stochastic Gradient Boosting ◽  
Biomass Dynamics

Accurate acquisition of spatial distribution of afforestation in a large area is of great significance to contributing to the sustainable utilization of forest resources and the evaluation of the carbon accounting. Annual forest maps (1986–2016) of Guangdong, China were generated using time series Landsat images and PALSAR data. Initially, four PALSAR-based classifiers were used to classify land cover types. Then, the optimal mapping algorithm was determined. Next, an accurate identification of forest and non-forest was carried out by combining Landsat-based phenological variables and PALSAR-based land cover classifications. Finally, the spatio-temporal distribution of forest cover change due to afforestation was created and its forest biomass dynamics changes were detected. The results indicated that the overall accuracy of forest classification of the improved model based on the PALSAR-based stochastic gradient boosting (SGB) classification and the maximum value of normalized difference vegetation index (NDVI; SGB-NDVI) were approximately 75–85% in 2005, 2010, and 2016. Compared with the Japan Aerospace Exploration Agency (JAXA) PALSAR-forest/non-forest, the SGB-NDVI-based forest product showed great improvement, while the SGB-NDVI product was the same or slightly inferior to the Global Land Cover (GLC) and vegetation tracker change (VCT)-based land cover types, respectively. Although this combination of multiple sources contained some errors, the SGB-NDVI model effectively identified the distribution of forest cover changes by afforestation events. By integrating aboveground biomass dynamics (AGB) change with forest cover, the trend in afforestation area closely corresponded with the trend in forest AGB. This technique can provide an essential data baseline for carbon assessment in the planted forests of southern China.

Sign in / Sign up

Export Citation Format

Share Document