Environmental Assessment
Volume B-4.4
Mine
Natural Habitats and Biodiversity
Ambatovy Project
297
January 2006
sampling intensity and distribution, and the types of taxa sampled. For several
taxonomic groups such as plants, ants and butterflies, species accumulation
curves did not asymptote, suggesting that further sampling would have generated
more species. This is not surprising considering the amount of effort required to
collect a detailed inventory of tropical species, even from one area (Lawton et al.
1998). In addition, sampling was restricted to the LSA which likely produced an
overestimate in the number of Priority 1 and Priority 2 endemic species that may
be impacted. There is a moderately good understanding of what the baseline
conditions are, however, fundamentally due to the complexity of the science,
there is a high degree of uncertainty in understanding the functional relationships
and mechanisms that have led to the current number and distribution of species
observed in the study area.
The amount of confidence in understanding impacts of the project is variable;
although it is well documented that habitat loss causes negative impacts on
populations and communities, the effects of impacts relating to fragmentation or
indirect disturbance are less well understood. Confidence in predicting impacts
therefore varies from low to moderate.
The cessation of mining activity and concurrent habitat reclamation is assumed to
help reverse the negative effects of the project (i.e., stabilize the ecosystem).
Early seral stages of zonal forest can be expected to establish quickly on
reclamation areas. Re-establishment of transitional habitat will likely be more
difficult, but a successful process will be developed through a series of site trials.
The azonal habitat is, however, not expected to return to its original state.
Stochastic events (e.g., fire, extreme drought or cyclones) and future human land
use practices (e.g., plantations, agriculture) may limit future biodiversity
potential of this area.
Monitoring
The overall objective of monitoring is to test the effectiveness of mitigation
measures, and detect unanticipated effects. In particular, should problems be
found with the viability of the on-site azonal conservation areas, then following
through with the protection of compensatory off-site areas would be required.
The monitoring program for biodiversity is composed of flora, fauna and fish
components (Volume B, Sections 4.1, 4.2 and 4.3). Changes to ecosystem
processes and function will focus on abiotic variables such as water quality,
hydrology and air quality (dust and air emissions). Habitat loss and
fragmentation metrics will also be assessed periodically (i.e., every two to three
years). Permanent sample plots will be established in azonal conservation areas.
Reclamation areas and habitats located at various distances from the mine
footprint will be monitored for selected flora and fauna species.
