skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Search for: All records

Creators/Authors contains: "Ma, Yaxiong"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Ecosystem destruction and biodiversity loss are now widespread, extremely rapid, and among the top global anthropogenic risks both in terms of likelihood and overall impact. Thorough impact evaluation of these environmental abuses—essential for conservation and future project planning—requires good analysis of local ecological and environmental data in addition to social and economic impacts. We characterized the deforestation and biodiversity impacts of energy investments in Southeast Asia using multiple geospatial data sources related to forest cover and loss data from 2000 to 2018, other landcover data, and the location, type, and characteristics of energy investments. This study paid particular attention to different types of power plants and financing sources. We identified critical buffer zones and forest structures impacted by these projects in accordance with IUCN criteria and spatial ecology. The paper introduces a novel, replicable analytical framework that goes beyond earlier studies in which all forests are treated as equivalent. It characterizes forests based on spatial morphological structures such as core forest, edges, islands, and bridges, allowing for a more nuanced understanding of deforestation and its impacts on biodiversity. Preliminary findings suggest that projects financed by Chinese development banks pose different risks compared to non-Chinese financing. The study also reveals significant differences in biodiversity impacts based on the type of energy source, be it coal or hydro. The study offers critical insights into the trade-offs between energy development and biodiversity conservation. It provides actionable metrics and strategies for policymakers, conservationists, and development banks to prioritize forest and habitat preservation in Southeast Asia and globally. 
    more » « less
  2. Animal-mediated seed dispersal is important for promoting forest regeneration and sustainability. Animal movement influences the distribution of seeds across the environment, resulting in spatially aggregated seed dispersal patterns. Animal seed dispersal patterns likely play an important role in the spatial structuring of tree populations: where a seed disperser moves influences the seed distribution. Environmental parameters that shape a disperser’s movement also influence the spatial distribution pattern of their seed dispersal. Orangutans are highly frugivorous and have been shown to disperse intact viable seeds. GPS locations were recorded for all orangutan defecations (n=1721) from 2014 to 2016 at the Cabang Panti Research Station in Gunung Palung National Park (GPNP), Indonesia. Our pilot research at GPNP measured seeds in fecal samples (n=98 fecal samples) and demonstrated that orangutan fecal samples do have intact seeds in more than 95% of t heir feces. A kernel density map was made using the defecation data to calculate the spatial density distribution of the defecations. A geographically weighted regression model (GWR) analyzed how well spatial parameters (altitude, slope, distance to river, and normalized difference vegetation index) predict the spatial density distribution of orangutan seed dispersal. All parameters in the GWR were statistically significant (R2=0.80, p<0.001) and showed low values for collinearity. The results show that orangutan seed dispersal is aggregated in space and the seed dispersal pattern is significantly shaped by environmental variables. This study provides us a better understanding of how the environment plays a role in determining animal behavior which influences the seed spatial distribution. Funders include the National Science Foundation (BCS-1638823), National Geographic Society, US Fish and Wildlife (F15AP00812), Leakey Foundation, Disney Wildlife Conservation Fund, and Nacey-Maggioncalda Foundation. 
    more » « less