Having approximated how vertebrate species are affected by logging, we would like to highlight some of the changes in concession management that could significantly boost wildlife survival in logged forests. Firstly, it is important to realize that, according to Act No. 5 of 1990 of the Government of Indonesia, concession managers in Indonesia have the obligation to prevent any activities detrimental to the survival of protected species (Ministry of Forestry 1990). This legal requirement has generally been ignored in the past and in many cases forests have been logged and clear-cut irrespective of the protected species that inhabited the areas. Clearly, improved law enforcement in concessions and increased accountability of concessionaires for their forest management is needed.
In addition, Meijaard et al. (in press) pointed out the inadequacy of the Act no. 5 of 1990 on protected species, because many species that are threatened with extinction are not included on the list of protected species. There is an immediate need to address this issue by investigating which IUCN listed species are presently not protected in Indonesia. With regards to this we suggested the following priorities regarding Malinau’s species. Prime candidates for inclusion on the Indonesian list of protected species are Ciconia stormi, Manouria emys, Orlitia borneensis, and Pelochelys cantorii (all listed as Endangered by the IUCN), Lophura erythrophthalma, Pycnonotus zeylanicus, Ptilocichla leucogrammica, Rollulus rouloul, Spilornis kinabaluensis, Treron capellei, Amyda cartilagina, Notochelys platynota, and Macaca nemestrina (all listed as Vulnerable), and Presbytis hosei (listed as Data Deficient by the IUCN). In addition, the government should investigate whether some species that are presently protected can be hunted for subsistence, e.g., Cervus unicolor, Muntiacus muntjak, Tragulus javanicus, and T. napu; this would require a change in the protection status of these species. Before doing so, the government should bear in mind that forest-dependent species such as the mouse-deer (Tragulus spp.) require the protection of large forest areas from settlement and fragmentation before any hunting can be considered potentially sustainable.
Once, the list of protected species is updated in accordance with global threat levels, there is an important need to identify the activities that are most detrimental to the survival of these species. As pointed out above, hunting is one of the most damaging to certain species that are targeted for consumption or trade, and its regulation should be a top priority in well-managed logging concessions. In Borneo, low forest productivity for wild animals places limits on the amount of exploitation and habitat modification that can be done sustainably. Bennett and Robinson (2000) and Fimbel et al. (2001) provided suggestions of how to curtail hunting in forest concessions. This includes:
Closing non-essential roads as soon as the operations are complete, which prevents hunter access from those roads, reduces market access, commercial hunting, and illegal trade, and it also reduces the opportunities for illegal re-entry logging;
The establishment of conservation zones within the concession where hunting is not allowed;
A prohibition on snare hunting as wasteful and unselective;
A prohibition on hunting protected species;
The banning of commercial hunting throughout the concession;
The development of a system of official hunters for controlled legal take of certain species for subsistence;
Ensuring that adequate fresh protein supplies are available to all staff and workers, thereby removing the need for them to hunt;
Link pay to productivity in an effort to reduce time available to employees for hunting;
Preventing logging company vehicles from carrying wildlife, thereby ensuring that they cannot be used for wild meat trade. Security checks at concession entry/exit points can enforce this measure as well as increasing security and preventing log theft.
Use contractual clauses specifying that violation of any of these regulations may result in loss of job, and meaningful enaction of this to malefactors.
Habitat heterogeneity and structural diversity are amongst the most important factors determining species-rich communities in natural forest settings, and the maintenance of these factors is important. Interventions may also be directed towards conserving specific resources or features (e.g., food trees, lianas, salt licks, caves, clean rivers), with importance for certain taxa. Such measures are relevant within harvesting zones, although these should be taken in addition to the identification of larger areas that will be excluded from any harvesting. Our recommendations concerning this include the following:
Reducing incidental damage to forests during harvesting. In particular, it is important to reduce the area of severely damaged forest, along tractor skid trails and log-loading areas, where vegetation and topsoil are most often removed. These areas are usually colonized first by vines and later by pioneer tree species. In general, except for some herbaceous Ficus and some lianas such weedy pioneers are not a good food resource for the majority of mammalian and avian frugivores (Chivers 1980). Worse still for vertebrate frugivores is the fact that one, or at most a few, species of pioneers tend to dominate in any particular area. Areas dominated by such trees and vines are in effect food deserts to many frugivores. Any reduction in the area of heavily disturbed forest should benefit frugivores by limiting the growth of pioneers. Also, minimizing the number of discontinuities in the canopy should reduce the impact on locomotion of nonvolant arboreals animals (Putz et al. 2001). Specific measures such as mapping important food or habitat trees, and special sites (e.g., burrows, wallows, riparian areas, salt springs), planning placement of skidder roads, use of light-weight, narrow, and wheeled rather than caterpillar skidders should reduce damage and reduce opportunities for invasion by pioneers. Practices can be improved if skidders are used; examples would be to drive with the blade up, reversing out of skid trails, and exploring extraction routes on foot rather than from the cab. Such changes require training and modified incentive schemes — but should lower operating costs as well as reducing damage. Other low-impact extraction methods should be explored, these include extraction by draught animals, lighter machinery, machinery with broad rubber tires, helicopters and skyline cables. These can considerably reduce soil compaction and erosion, and damage to non-harvested trees and vegetation in general.
Preserve canopy and mid-canopy fig trees. Regarded as a keystone food resource for a wide range of tropical frugivores, fig trees have special significance in preserving fauna. Figs (Ficus spp.) are especially important for wildlife as they provide fruit throughout the year, and fulfil vital nutritional needs, such as the calcium needed by vertebrates living on otherwise mineral poor diets (see O'Brien et al. 1998). Strangling figs also provide important refuge habitat for primates, civets, bats, rodents, squirrels, bears, binturongs, and birds. Because of the canopy germination habit of many figs, protection of larger mature individuals appears the only viable measure of conservation during felling (Johns 1997); however, given the extended length of time to maturity, efforts should be made to conserve as many figs as possible, regardless of age.
Interior forest conditions should be better protected. Many vertebrates, especially amphibians, reptiles, and forest interior birds, require moist, relatively shady conditions. By maintaining as much canopy as possible, lower levels of the forest will not be subject to the drying influences of intense sunlight. Preserving the forest canopy will also aid in preserving leaf litter habitat. Roads and trails should be planned carefully, and constructed in a way that minimizes canopy damage. They should be kept short and narrow (a maximum overall width of 4 m is recommended by DFID 1999) and, if possible, overhead canopy contact should be maintained. The area scraped and compacted by heavy machinery should be minimized; this is more effective revegetation management than attempting to rehabilitate these areas following logging (Pinard et al. 1996; Pinard et al. 2000).
Standing dead or part dead trees should be left standing or intact. Large, old and hollow trees have considerable significance for many forest taxa that utilise or are dependent on them, e.g., hornbills (Datta 1998; Whitney et al. 1998; Whitney & Smith 1998), woodpeckers (McNally & Schneider 1996) and other hollow tree users (Zahner 1993), including bears, civets, and porcupines. The loss of such large stems can have long-term influences (Gordon et al. 1990) and, although not well documented, is a potential cause of otherwise inexplicable decline or failure in forest regeneration in various parts of the world, another factor possibly being the loss of mycorrhizal fungi that slows down recolonisation of clear-fells. Trees that are infected by heart-rot should be retained as much as possible as these provide hollows of importance to vertebrates that use them for breeding, nesting, and food storage. A traditional silvicultural technique for fighting heart-rot fungi is too remove dying and dead trees and burning them (Elouard 1998), and it needs to be assessed how much is gained or lost in economic and ecological terms if this practice is continuated.
Retain ground cover. Of special note in Indonesia, is that within the logging regulations, concession-holders are legally required to repeatedly slash all undergrowth and climbers for several years after felling with the intention of reducing aggressive ‘weeds’ and encouraging regeneration; in practice, though, this has a deleterious effect on many species, including rattan and timber seedlings (see 2003a; Sheil et al. 2003b). Unfortunately this activity seems to have been largely unrecognised by conservationists and has not been assessed. In Malinau, it is notable that compartments slated for logging are often incompletely accessed due to extreme gradients and rugged difficult terrain — so it is not uncommon for more than half a logged compartment to remain unlogged after harvesting is ‘complete’ — in contrast the slashing treatment is applied on foot and no areas are omitted making it a much more general and obvious impact on ‘logged areas’ (D. Sheil, pers obs. 1998–2003). Even if applied properly, the silvicultural benefits of the technique appear limited while the impacts on biodiversity and communities are considerable (note that the impacts of slashing on wildlife are not closely assessed but it is clear that the understorey is greatly affected (Sheil et al. 2003a, b; Sheil unpublished data). Slashing of undergrowth and climbers may be as damaging to the forest as harvesting itself and we suggest that the policy that stipulates it be reviewed.
Prevent siltation of streams. Many amphibians, and some reptiles, birds, fish, and possibly otters and the Otter Civet (Cynogale bennettii) depend on clear water for breeding and feeding. Proper drainage systems that feed into vegetated areas and well-constructed and well-maintained bridges and culverts are important in keeping streams clear. Furthermore, law requires the establishment of logging exclusion zones around streams and waterways. Proper implementation of these laws will have a significant positive impact on aquatic ecosystems in timber concessions.
Avoid soil compaction. Whenever possible soil compaction should be reduced by limiting logging activities to dry periods, or by planning different working areas for dry weather and wet weather to minimize erosion (DFID 1999). Many species of tropical reptiles and amphibians are fossorial or spend significant periods of time below ground. Logging during dry periods may also limit stream siltation resulting from opening of the canopy. One means to improve soil recovery is to ensure that small woody waste ('brash') is added onto the surface of skid trails during operations – this reduces erosion and increases subsequent biological activity in the soils, speeding soil recovery.
Maintain interior forest connectivity. Maintaining corridors of interior forest can have positive effects on the vertebrate fauna (Marcot et al. 2001). Corridors of habitat connect patches of undisturbed forest, thus facilitating dispersal of animals that will not enter open areas. In Meijaard et al.’s (in press) recommendations a forest area network is suggested. This is based on two forest elements: reserved areas and linking corridors. Reserved areas are protected for what they are or what they do (e.g., watershed protection, hunting areas, grave-sites, critical habitat for particular species). Corridor forests are sections of forest required to keep these reserved areas connected to each other.
Ensure adequate recovery periods. There is a need of the organization of annual felling coupes with some degree of dispersal throughout the forest to facilitate regeneration and migration of wildlife disturbed by logging (DFID 1999). If possible, this should involve closing some roads temporarily so that animals can migrate undisturbed and hunting pressure is reduced. The main means to do this is to dismantle river crossings (culverts) or by gating, and, when no longer in use, roads should be permanently closed (blocked or partially destroyed) (Mason & Thiollay 2001) and rehabilitated to a more natural condition.
Ensure implementation of legal requirements. Means of enforcement should be built into guidelines. Since the Ministry of Forestry and local governments control logging and the concession controls security, it should be a combination of self-policing with check-ups by KSDA, and other designated government representatives. Opportunities for involvement and verification should be given to other major stakeholders (community representatives, NGOs etc.) and to agreed third parties. Foresty certification audits, if applicable, provide one means to gauge success.
If carried out in areas selected for logging, these recommendations should help considerably in protecting populations of vertebrates in tropical forests. However, these recommendations will not be successful without an overall plan for sustainable management of tropical forests and appropriate implementation of enforcement measures. Blockhus et al. (1992) proposed such a plan, which included
Creation of a protected system linked by natural forest corridors;
Establishment of monitoring programs to ensure effective implementation;
Implementation of remedial action before changes are irreversible.
Finally, long-term goals should balance economic benefits with environmental costs to conserve all components of biodiversity, including vertebrates.