|One of the major goals for national parks is to preserve of less human disturbed landscapes so that they can be enjoyed by future generations. To achieve that goal, a key determinant is the maintenance of ecological resilience and stability. Ecological resilience refers to an ecosystem's ability to maintain integrity after disturbance; while the general concept of stability relates to an ecosystem's tendency to return to its equilibrium status after disturbance.
Given the enormous changes in global environments and ecologies, however, national park landscapes now suffer from stress at various levels caused by natural cycles or human disturbances. The changes can be broadly divided into global environmental changes (warming and pollution) and the loss of biodiversity.
Ecologies in national parks are no exception to stresses caused by these environmental changes. If the report by the Intergovernmental Panel on Global Change of the United Nations holds true, then the global temperature has climbed 0.74℃ and by the end of this century there could be an additional 1.1 to 6.4℃, leading to global climate and hydrology changes. Not only pole regions, glaciers, oceans and currents, littoral wetlands, lagoons and other habitats would be affected at a global scale, the occurrence, frequency and intensity of tropical cyclones such as hurricane, typhoon and tsunami, wild fires and droughts, flooding, epidemic diseases would also exacerbate.
The increase of carbon dioxide in the atmosphere sets off a warming effect on Earth and fertilization effect on plants. Added with human-caused acid deposition, atmospheric input of plant nutrients (especially nitrogen and sulfur) is increasing rapidly, further causing nutrient imbalance in plants.
Over a long period of time, these effects would gradually exert an impact on the biodiversity in all corners of the world, affecting processes of life such as plant productivity, nutrient cycling, and decomposition of organic matter as well as the trophic dynamics of the entire life system. Other changes in phenological phenomena would especially affect the stability and resilience of ecosystems. For instance, changes of seasonal patterns in plant rooting development, foliation, blooming, fruiting, defoliation and dormancy; and
||disorder in animal hibernation, migration, foraging and breeding. Seasonal disparity would occur in the long-term relationship between animals and plants that are closely and mutually dependant, including animals' feeding on foliage, pollination and fertilization, fruiting, seed disposal and seedling regeneration and growth.
In this century, national park managements cannot afford to overlook the impacts brought about by global changes or ignore signs of maladapted ecological phenomena and processes to environmental changes. It would be too late if the resilience and stability of ecosystem are destructed.
It is therefore essential for national park managements to seriously examine the problem and its consequences and take actions adjusting to global changes. New management strategies should be proposed. Upper-level administrative authorities of national park managements should employ specific policies and show commitment to and determination in solving the problem. Whether or not global warming is caused by human activities, governments must adopt immediate and effective measurements to control consumptions of fossil fuel and protect forest landscapes. The scope of protective actions taken by national parks should not be limited to management of territory within the park boundaries but should include the entire country, region and even the world via international collaborations.
In terms of strategies adjusted to global changes, national park managements can consider adopting an “adaptive management model” that integrates “designing, management and monitoring.” Testing assumptions systematically can further lower uncertainties during the process of adaptive management and achieve “improvements and learning”. These are some ways for the managements to confront the stress accompanied by environmental changes.
A committed government would mean sufficient research funds, more researchers and sound data management systems in its national parks. With global change becoming the Achilles' heel of landscape preservation efforts, it is time for national park managements to initiate and actively face the problem with holistic strategies and immediate actions.