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Timber Extraction (timber + extraction)

Distribution by Scientific Domains
Life Sciences75%

Selected Abstracts

Prospects for conserving biodiversity in Amazonian extractive reserves

ECOLOGY LETTERS, Issue 3 2002
Susan M. Moegenburg
Abstract Non-timber forest product (NTFP) extraction is a popular alternative to timber extraction that figures prominently in efforts to utilize tropical forests sustainably. But the ability to conserve biodiversity through NTFP management, particularly in extractive reserves in Amazonia, has remained untested. We found that intensive management of Euterpe oleracea (Palmae) fruit, one of the most important extractive products in the Amazon, has substantial impacts on biodiversity, whereas moderate management does not. We mimicked traditional levels of fruit harvest in a replicated experiment over one fruiting season. High-intensity harvest (75% of fruits removed) reduced avian frugivore species diversity by 22%. Low-intensity harvest (40% of fruits removed), however, had no effect on diversity. On a larger scale, we found that forests with enriched densities of E. oleracea supported more fruit-eating birds but fewer non fruit-eating birds than non-enriched forests. Taken together, these results suggest that intensive NTFP management to meet market demands may trigger substantial ecological impacts, at least at the level of our study. E. oleracea harvest should be limited where conservation of biodiversity is a goal. [source]

Streamwater quality as affected by wild fires in natural and manmade vegetation in Malaysian Borneo

HYDROLOGICAL PROCESSES, Issue 5 2004
Anders Malmer
Abstract In 1998 a wild fire struck a paired catchment research area under long-term monitoring of hydrological and nutrient budgets. Streamwater quality as concentrations of dissolved and suspended particulate matter was monitored during 1·5,2·5 years after the fire in streams from seven different catchments. As the catchments, due to earlier experimental treatments, had different vegetations, varying effects related to different fire intensities were observed. The highest, mean stormflow, suspended sediment concentrations resulted from intensive fire in secondary vegetation that had experienced severe soil disturbance in previous treatments (crawler tractor timber extraction 10 years earlier). Stormflow concentrations were typically still about 400 mg l,1 in 1999 (10,21 months after the fire), which was about the maximum recorded concentration in streams during initial soil disturbance in 1988. Forest fire in natural forest resulted in less than half as high stormflow concentrations. For dissolved elements in streamwater there was a positive relation between fuel load (and fire intensity) and concentration and longevity of effects. Stream baseflow dissolved nutrient concentrations were high in the months following the fire. Mean baseflow K concentrations were 8,15 mg l,1 in streams draining catchments with intensive fire in secondary vegetation with large amounts of fuel. After controlled fire for forest plantation establishment in 1988 corresponding concentrations were 3,5 mg l,1, and after forest fire in natural forest in this study about 2 mg l,1. This study shows differences in response from controlled fire for land management, forest fire in natural forests and wild fires in manmade vegetations. These differences relate to resistance and resilience to fire for the involved ecosystems. There is reason to believe that wild fires and repeated wild fires during or after droughts, in successions caused by human influence, may lead to larger losses of ecosystem nutrient capital from sites compared with forest fires in natural forests. As fire in the humid tropics becomes more common, in an increasingly spatially fragmented landscape, it will be important to be aware of these differences. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Effect of Grazing on Restoration of Endemic Dwarf Pine (Pinus culminicola Andresen et Beaman) Populations in Northeastern Mexico

RESTORATION ECOLOGY, Issue 1 2005
J Jiménez
Abstract A pilot experiment designed to test the effect of cattle, small mammals, and elevation on the success of reforestation of an endemic dwarf pine species in northeastern Mexico was implemented. Pinus culminicola (Andresen et Beaman) grows only in four high peaks in the Sierra Madre Oriental and is under pressure from grazing, wildfires, and human activities such as mining, road development for timber extraction, and telecommunication and aerial navigation devices. We planted and monitored 2-year-old seedlings at three elevations within the natural distribution range of this species at Cerro El Potosí in Nuevo León, Mexico. At each elevation three treatments were established: (1) seedlings protected from cattle plus small mammals, (2) seedlings protected from cattle, and (3) seedlings with free access to cattle and small mammals. Seedling survival was approximately 50% in (1) after 4 years, but there were no surviving seedlings with free access to cattle. Elevation in general did not account for variation in survival. Seedling growth was poor during the 4 years, which implies that seedlings remain susceptible to grazing and trampling by cattle and small mammals. The implications for a large-scale restoration program are discussed. [source]

Phylogenetic Age is Positively Correlated with Sensitivity to Timber Harvest in Bornean Mammals

BIOTROPICA, Issue 1 2008
Erik Meijaard
ABSTRACT The reasons that forest vertebrates differ in their response to selective timber extraction in tropical forests remain poorly characterized. Understanding what determines response and sensitivity can indicate how forest management might yield greater conservation benefits, and help us identify which lesser-known species may be especially vulnerable. We assessed the response of 41 Bornean mammals to selective timber harvest and tested eight hypotheses regarding the correlation between those responses and a range of species characteristics. Multivariate analyses show that phylogenetic species age is a key variable determining sensitivity. Older species are less able to cope with the effects of selective timber harvest. Most of these species are endemic to insular southeast Asia, and do not occur on the Asian mainland. These species are more specialized, and appear less able to cope with habitat change. In contrast, species tolerant to logging evolved more recently. This group tends to be omnivorous or herbivorous, to use all vegetation strata, and to be regionally widespread. This finding allows the sensitivity to habitat disturbance of lesser-known species to be predicted, and therefore has important conservation implications. These new insights also help in the design of large-scale forest landscapes that combine sustainable forest management and species conservation requirements. We recognize that these functions can be compatible, but that some species still need completely protected areas for their survival. RINGKASAN Hingga saat ini belum banyak penelitian mengungkapkan bagaimana berbagai vertebrata hutan akan bereaksi ketika dilakukan pembalakan hutan secara selektif. Dengan mempelajari tingkat reaksi dan kepekaan vertebrata, maka dapat diketahui bagaimana pengelolaan hutan dapat memberikan manfaat konservasi yang lebih besar. Penelitian demikian dapat membantu kami mengidentifikasi spesies mana saja yang biologinya sedikit diketahui namun termasuk rentan kepunahan. Kami mengevaluasi tanggapan 41 spesies mamalia Kalimantan/Borneo terhadap pemanenan kayu secara selektif, dan selanjutnya menguji 8 hipotesa berkaitan dengan hubungan atau korelasi antara tanggapan yang terjadi dengan berbagai karakteristik dari masing-masing spesies yang diteliti. Berdasarkan analisis multivarian disimpulkan bahwa umur filogenetik dari masing-masing spesies merupakan penentu kelentingan masing-masing spesies tersebut terhadap dampak pemanenan selektif. Spesies yang berumur lebih tua cenderung kurang dapat mentolerir dampak pemanenan kayu. Kebanyakan spesies ini merupakan endemik kepulauan di Asia Tenggara. Spesies ini cenderung merupakan spesialis (memiliki niche yang lebih sempit), serta tampaknya tidak seberapa kuat menerima dampak perubahan habitat. Sebaliknya spesies yang lebih toleran terhadap pembalakan cenderung baru berevolusi belakangan ini. Kelompok ini cenderung bersifat omnivora atau herbivora, serta mampu menggunakan seluruh lapisan vegetasi yang ada, serta tersebar meluas. Berdasarkan penelitian ini, dimungkinkan dilakukan prakiraan terhadap kepekaan dan dengan demikian terdapat berbagai manfaat praktis dalam hal metodologi. Analisis ini juga dapat membantu perancangan lanskap hutan berskala besar, dengan menggabungkan pengelolaan hutan berkelanjutan serta kebutuhan konservasi spesies. Kami melihat bahwa kedua kebutuhan pengelolaan tersebut dapat dipadu-serasikan, namun untuk beberapa spesies akan mutlak dibutuhkan kawasan yang dilindungi penuh demi kelanjutan spesies-spesies tersebut. [source]