scholarly journals Invasion of Acacia mearnsii stands by natural forest species at Buffeljagsrivier, Swellendam: The process

2017 ◽  
Vol 109 ◽  
pp. 335
Author(s):  
C.J. Geldenhuys ◽  
A. Atsema-Edda ◽  
M.W. Mugure
Author(s):  
He Pia He Pia

Abstract In the Mekong Region, the expansion of rubber plantations is a major threat to the remaining natural forests and has led to a considerable degradation of biodiversity. The shift from traditional agriculture to rubber cultivation additionally reduced landscape and agricultural system diversity and with this, the availability of potentially useful habitat types for species originating from natural forest. In most cases, monoculture rubber plantations showed to harbour less than half of the species richness in various plant and animal groups compared with natural forest, and often it was found or being assumed that many of these species are unable to exist permanently in rubber plantations. There is clear evidence that the existence natural forest area is essential for the conservation of large portions of native forest species in rubber-dominated landscapes. Alteration of rubber monoculture land use can only contribute effectively to species conservation if natural forest plots remain. Furthermore, suggested restoration concepts such as the conversion of rubber plantations into forest on marginal sites and land-sharing approaches are currently only vaguely described, and their contribution to the conservation of native forest species remains uncertain. In addition, modalities of stakeholder involvement, economic compensation and ecologically reasonable implementation of such measures are still unexplained. As an ecologically reasonable and economically feasible method to improve species diversity in rubber monoculture plantations, we suggest the promotion of natural undergrowth vegetation to enlarge suitable habitat structures in connection with natural forest. This can be reached through the cease of weeding and herbicide application and potentially through the cultivation of useful wild plants.


Tropics ◽  
2018 ◽  
Vol 26 (4) ◽  
pp. 111-121
Author(s):  
Ryo Kitamura ◽  
Naoki Okada ◽  
Masaharu Sakai ◽  
Thiti Visaratana ◽  
Ratana Thai-ngam ◽  
...  

2007 ◽  
Vol 31 (2) ◽  
pp. 287-298 ◽  
Author(s):  
Antonio Carlos da Gama-Rodrigues ◽  
Nairam Félix de Barros ◽  
Nicholas Brian Comerford

The objective of this paper is to study selected components of the nutrient cycle of pure and mixed stands of native forest species of Atlantic Forest in southeastern Brazil. Tree diameter, height, above-ground biomass, and nutrient content were determined in 22-year-old stands. Litterfall, litter decomposition, and nutrient concentration were evaluated from August 1994 to July 1995. The following species were studied: Peltogyne angustiflora, Centrolobium robustum, Arapatiella psilophylla, Sclerolobium chrysophyllum, Cordia trichotoma, Macrolobium latifolium. The litter of a natural forest and a 40-year-old naturally regenerated second-growth forest was sampled as well. The mixed-species outmatched pure stands in height, stem volume and total biomass (29.4 % more). The greatest amount of forest litter was observed in the natural forest (9.3 Mg ha-1), followed by the mixed-species stand (7.6 Mg ha-1) and secondary forest (7.3 Mg ha-1), and least litterfall was measured in the pure C. robustum stand (5.5 Mg ha-1). Litterfall seasonality varied among species in pure stands (CV from 44.7 to 91.4 %), unlike litterfall in the mixed-tree stand, where the variation was lower (CV 31.2 %). In the natural and second-growth forest, litterfall varied by 57.8 and 34.0 %, respectively. The annual rate of nutrient return via litterfall varied widely among forest ecosystems. Differences were detected between forest ecosystems in both the litter accumulation and quantity of litterlayer nutrients. The highest mean nutrient accumulation in above-ground biomass was observed in mixed-species stands. The total nutrient accumulation (N + P + K+ Ca + Mg) ranged from 0.97 to 1.93 kg tree-1 in pure stands, and from 1.21 to 2.63 kg tree-1 in mixed-species stands. Soil fertility under mixed-species stands (0-10 cm) was intermediate between the primary forest and pure-stand systems. The litterfall rate of native forest species in a mixed-species system is more constant, resulting in a more continuous decomposition rate. Consequently, both nutrient availability and quantity of organic matter in the soil are higher and the production system ecologically more sustainable.


Author(s):  
Adam S. Forbes ◽  
David A. Norton ◽  
Fiona E. Carswell

Background: We investigated the long-term potential of non-harvest Pinus radiata plantations for the facilitation and restoration of a natural forest community dominated by indigenous woody species. We investigated the relationship between indigenous regeneration and light levels and the hypothesis that proximity to indigenous seed sources is critical. We studied nine Pinus radiata stands of different ages located within Kinleith Forest, which is a large (ca. 66 000 ha) commercial exotic plantation forest located in New Zealand’s central North Island. Methods: We constructed a chronosequence of P. radiata plantation stands aged 2–89 years to represent long-term natural forest regeneration following plantation establishment. We surveyed structural, compositional and contextual aspects of this secondary succession and compared these results with an old-growth indigenous forest reference site located within the study area. Results: The exotic P. radiata canopy facilitated a regeneration trajectory characterised by shade-tolerant indigenous forest species. We found that the structure and composition of P. radiata understories were strongly influenced by stand age and proximity to indigenous forest. Stand age was important from the perspective of creating shaded conditions for the establishment of shade-tolerant woody forest species. Our results suggest that proximal indigenous forest was required for the consistent natural establishment of larger-fruited, bird-dispersed mature forest canopy species in P. radiata plantations. Conclusions: Our results showed that, even at ecologically isolated sites, the microclimate conditions created by plantation Pinus radiata stands supported a suite of readily-dispersed indigenous forest plants. Based on these results we suggest that non-harvest P. radiata stands provide an important opportunity for the restoration of indigenous forest communities in New Zealand’s production landscapes. Where restoration of forest composition similar to old-growth is the restoration objective, however, interventions might be necessary to direct and accelerate the secondary forest succession. Further replicated study is required into the relationship between native forest proximity and understorey regeneration patterns.


2009 ◽  
Vol 160 (11) ◽  
pp. 334-340 ◽  
Author(s):  
Pierre Mollet ◽  
Niklaus Zbinden ◽  
Hans Schmid

Results from the monitoring programs of the Swiss Ornithological Institute show that the breeding populations of several forest species for which deadwood is an important habitat element (black woodpecker, great spotted woodpecker, middle spotted woodpecker, lesser spotted woodpecker, green woodpecker, three-toed woodpecker as well as crested tit, willow tit and Eurasian tree creeper) have increased in the period 1990 to 2008, although not to the same extent in all species. At the same time the white-backed woodpecker extended its range in eastern Switzerland. The Swiss National Forest Inventory shows an increase in the amount of deadwood in forests for the same period. For all the mentioned species, with the exception of green and middle spotted woodpecker, the growing availability of deadwood is likely to be the most important factor explaining this population increase.


1999 ◽  
Vol 150 (12) ◽  
pp. 484-488 ◽  
Author(s):  
Wolf Hockenjos

Concepts of near-natural forestry are in great demand these days. Most German forest administrations and private forest enterprises attach great importance to being as «near-natural» as possible. This should allow them to make the most of biological rationalisation. The concept of near-natural forestry is widely accepted, especially by conservationists. However, it is much too early to analyse how successful near-natural forestry has been to date, and therefore to decide whether an era of genuine near-natural forest management has really begun. Despite wide-spread recognition, near-natural forestry is jeopardised by mechanised timber harvesting, and particularly by the large-timber harvester. The risk is that machines, which are currently just one element of the timber harvest will gain in importance and gradually become the decisive element. The forest would then be forced to meet the needs of machinery, not the other way round. Forests would consequently become so inhospitable that they would bear no resemblance to the sylvan image conjured up by potential visitors. This could mean taking a huge step backwards: from a near-natural forest to a forest dominated by machinery. The model of multipurpose forest management would become less viable, and the forest would become divided into areas for production, and separate areas for recreation and ecology. The consequences of technical intervention need to be carefully considered, if near-natural forestry is not to become a thing of the past.


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