Publications by authors named "Billy C H Hau"

Article Synopsis
  • Forest restoration is essential for combating climate change and land degradation, and assessing the costs and benefits of different restoration strategies (active restoration vs. natural regeneration) is crucial for effective outcomes.
  • Current studies often overlook the potential of natural regeneration, leading to gaps in understanding the full benefits and questioning the need for active restoration methods.
  • The study conducted in Hong Kong uses advanced LiDAR data to evaluate vegetation recovery and demonstrates a new framework that combines restoration and regeneration potential, ultimately helping policymakers prioritize restoration efforts to optimize ecosystem recovery.
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Suspended solids concentration (SSC) in a river is closely relevant to river water turbidity. Investigation of their relationship in this study is accompanied by observed turbidity and SSC values, which were obtained from the testing results of water samples and monitored conditions in streamflow. The water samples were collected from two observation stations with a broad range of sediment concentrations in the Lai Chi Wo catchment in Hong Kong, China.

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Soil microbial communities are important for plant growth and establishing healthy ecosystems. Although biochar is widely adopted as a sustainable fertilizer, its influence on soil ecological functions is still unclear, especially under climate change such as elevated carbon dioxide concentration (eCO). This study explores the coupled effects between eCO and biochar on microbial communities in soil planted with tree seedlings of Schefflera heptaphylla.

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River turbidity is an important factor in evaluating environmental water quality, and turbidity dynamics can reflect water sediment changes. During rainfall periods, specifically in mountainous areas, river turbidity varies dramatically, and knowledge of spatiotemporal turbidity variations in association with rainfall features and farming activities is valuable for soil erosion prevention and catchment management. However, due to the difficulties in collecting reliable field turbidity data during rainstorms at a fine temporal scale, our understanding of the features of turbidity variations in mountainous rivers is still vague.

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Legumes provide an essential service to ecosystems by capturing nitrogen from the atmosphere and delivering it to the soil, where it may then be available to other plants. However, this facilitation by legumes has not been widely studied in global tropical forests. Demographic data from 11 large forest plots (16-60 ha) ranging from 5.

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Article Synopsis
  • Climate plays a crucial role in shaping biodiversity across different latitudes, but many studies overlook the distinction between direct and indirect effects of climate on biodiversity.
  • Research using data from 35 large forest plots shows that climate directly affects tree species richness, favoring warm and moist environments.
  • The findings suggest that climatic conditions not only directly limit species diversity but also promote greater species richness by supporting higher stem abundance and facilitating (co-)evolution in productive warm climates.*
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Exploration for estimating rainfall and runoff extremes in ungauged catchments is challenging since there are no field measurements of rainfall and streamflow for confirming study results. This study proposed a systematic approach to tackle the challenge, and the approach includes field survey, rainfall data collection, frequency analysis, installation of equipment in the study area, and numerical modeling. The approach was then applied to the Lai Chi Wo (LCW) catchment in Hong Kong, China, in order to evaluate the severity of a rainstorm and flood event occurred on 11 May 2014.

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Populations of the big-headed turtle are declining at unprecedented rates across most of its distribution in Southeast Asia owing to unsustainable harvest for pet, food, and Chinese medicine markets. Research on Asian freshwater turtles becomes more challenging as populations decline and basic ecological information is needed to inform conservation efforts. We examined fecal samples collected from in five streams in Hong Kong to quantify the diet, and we compared the germination success of ingested and uningested seeds.

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Global change is impacting forests worldwide, threatening biodiversity and ecosystem services including climate regulation. Understanding how forests respond is critical to forest conservation and climate protection. This review describes an international network of 59 long-term forest dynamics research sites (CTFS-ForestGEO) useful for characterizing forest responses to global change.

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Harvesting pressure on Asian freshwater turtles is severe, and dramatic population declines of these turtles are being driven by unsustainable collection for food markets, pet trade, and traditional Chinese medicine. Populations of big-headed turtle (Platysternon megacephalum) have declined substantially across its distribution, particularly in China, because of overcollection. To understand the effects of chronic harvesting pressure on big-headed turtle populations, we examined the effects of illegal harvesting on the demography of populations in Hong Kong, where some populations still exist.

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