scholarly journals Patterns of biodiversity response along a gradient of forest use in Eastern Amazonia, Brazil

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8486
Author(s):  
Sérgio G. Milheiras ◽  
Marcelino Guedes ◽  
Fernando Augusto Barbosa Silva ◽  
Perseu Aparício ◽  
Georgina M. Mace

The preservation of tropical forests is increasingly at risk, including forests located within human-modified landscapes that retain high conservation value. People modify and interact with these landscapes through a wide range of uses. However, our knowledge of how different forest uses affect biodiversity is limited. Here, we analyse the responses of different taxa to four distinct categories of forest management, namely old-growth forest, Brazil nut extraction areas, reduced impact logging areas, and eucalyptus plantations. Within six independent replicates of each category, we sampled three taxa (fruit-feeding butterflies, dung beetles, and trees) in eastern Amazonia. Forests under moderate use (Brazil nut extraction and reduced-impact logging) had similar, albeit slightly lower, diversity levels relative to old-growth forests, while communities in plantations were significantly less diverse. Only 4%, 20%, and 17%, of the sampled butterfly, dung beetle, and tree species, respectively, were restricted to old-growth forests. This study provides further empirical evidence of the importance of old-growth forest conservation in the context of human-modified landscapes. It also suggests that landscape matrices integrating forest uses at varying intensities are well positioned to reconcile biodiversity conservation with the production of goods that support local livelihoods.

2021 ◽  
Vol 13 (7) ◽  
pp. 1233
Author(s):  
Ben Spracklen ◽  
Dominick V. Spracklen

A forest’s structure changes as it progresses through developmental stages from establishment to old-growth forest. Therefore, the vertical structure of old-growth forests will differ from that of younger, managed forests. Free, publicly available spaceborne Laser Range and Detection (LiDAR) data designed for the determination of forest structure has recently become available through NASA’s General Ecosystem and Development Investigation (GEDI). We use this data to investigate the structure of some of the largest remaining old-growth forests in Europe in the Ukrainian Carpathian Mountains. We downloaded 18489 cloud-free shots in the old-growth forest (OGF) and 20398 shots in adjacent non-OGF areas during leaf-on, snow-free conditions. We found significant differences between OGF and non-OGF over a wide range of structural metrics. OGF was significantly more open, with a more complex vertical structure and thicker ground-layer vegetation. We used Random Forest classification on a range of GEDI-derived metrics to classify OGF shapefiles with an accuracy of 73%. Our work demonstrates the use of spaceborne LiDAR for the identification of old-growth forests.


2021 ◽  
Vol 4 ◽  
Author(s):  
Maxence Martin ◽  
Pierre Grondin ◽  
Marie-Claude Lambert ◽  
Yves Bergeron ◽  
Hubert Morin

Large primary forest residuals can still be found in boreal landscapes. Their areas are however shrinking rapidly due to anthropogenic activities, in particular industrial-scale forestry. The impacts of logging activities on primary boreal forests may also strongly differ from those of wildfires, the dominant stand-replacing natural disturbance in these forests. Since industrial-scale forestry is driven by economic motives, there is a risk that stands of higher economic value will be primarily harvested, thus threatening habitats, and functions related to these forests. Hence, the objective of this study was to identify the main attributes differentiating burned and logged stands prior to disturbance in boreal forests. The study territory lies in the coniferous and closed-canopy boreal forest in Québec, Canada, where industrial-scale logging and wildfire are the two main stand-replacing disturbances. Based on Québec government inventories of primary forests, we identified 427 transects containing about 5.5 circular field plots/transect that were burned or logged shortly after being surveyed, between 1985 and 2016. Comparative analysis of the main structural and environmental attributes of these transects highlighted the strong divergence in the impact of fire and harvesting on primary boreal forests. Overall, logging activities mainly harvested forests with the highest economic value, while most burned stands were low to moderately productive or recently disturbed. These results raise concerns about the resistance and resilience of remnant primary forests within managed areas, particularly in a context of disturbance amplification due to climate change. Moreover, the majority of the stands studied were old-growth forests, characterized by a high ecological value but also highly threatened by anthropogenic disturbances. A loss in the diversity and functionality of primary forests, and particularly the old-growth forests, therefore adds to the current issues related to these ecosystems. Since 2013, the study area is under ecosystem-based management, which implies that there have been marked changes in forestry practices. Complementary research will be necessary to assess the capacity of ecosystem-based management to address the challenges identified in our study.


2020 ◽  
Vol 50 (2) ◽  
pp. 155-169 ◽  
Author(s):  
Maxence Martin ◽  
Nicole J. Fenton ◽  
Hubert Morin

The erosion of old-growth forests in boreal managed landscapes is a major issue currently faced by forest managers; however, resolving this problem requires accurate surveys. The intention of our study was to determine if historic operational aerial forest surveys accurately identified boreal old-growth forests in Quebec, Canada. We first compared stand successional stages (even-aged vs. old-growth) in two aerial surveys performed in 1968 (preindustrial aerial survey) and 2007 (modern aerial survey) on the same 2200 km2 territory. Second, we evaluated the accuracy of the modern aerial survey by comparing its results with those of 74 field plots sampled in the study territory between 2014 and 2016. The two aerial surveys differed significantly; 80.8% of the undisturbed stands that were identified as “old-growth” in the preindustrial survey were classified as “even-aged” in the modern survey, and 60% of the stands identified as “old-growth” by field sampling were also erroneously identified as “even-aged” by the modern aerial survey. The scarcity of obvious old-growth attributes in boreal old-growth forests, as well as poorly adapted modern aerial survey criteria (i.e., criteria requiring high vertical stratification and significant changes in tree species composition along forest succession), were the main factors explaining these errors. It is therefore likely that most of Quebec’s boreal old-growth forests are currently not recognized as such in forest inventories, challenging the efficacy of sustainable forest management policies.


2021 ◽  
Vol 4 ◽  
Author(s):  
Jeffrey Opoku-Nyame ◽  
Alain Leduc ◽  
Nicole J. Fenton

Clear cut harvest simplifies and eliminates old growth forest structure, negatively impacting biodiversity. Partial cut harvest has been hypothesized (1) to have less impact on biodiversity than clear cut harvest, and (2) to encourage old growth forest structures. Long-term studies are required to test this hypothesis as most studies are conducted soon after harvest. Using epixylic bryophytes as indicators, this study addresses this knowledge gap. Fourteen years after harvest, we examined changes in epixylic bryophyte community composition richness and traits, and their microhabitats (coarse woody debris characteristics and microclimate) along an unharvested, partial cuts and clear cuts harvest treatment in 30 permanent plots established in the boreal black spruce (Picea mariana) forests of northwestern Quebec, Canada. Our results were compared to those of an initial post-harvest study (year 5) and to a chronosequence of old growth forests to examine species changes over time and the similarity of bryophyte communities in partial cut and old growth forests. Coarse woody debris (CWD) volume by decay class varied among harvest treatments with partial cuts and clear cuts recording lower volumes of early decay CWD. The epixylic community was richer in partial cuts than in mature unharvested forests and clear cuts. In addition, species richness and overall abundance doubled in partial and clear cuts between years 5 and 14. Species composition also differed among treatments between years 5 and 14. Furthermore, conditions in partial cut stands supported small, drought sensitive, and old growth confined species that are threatened by conditions in clear cut stands. Lastly, over time, species composition in partial cuts became more similar to old growth forests. Partial cuts reduced harvest impacts by continuing to provide favorable microhabitat conditions that support epixylic bryophytes. Also, partial cut harvest has the potential to encourage old growth species assemblages, which has been a major concern for biodiversity conservation in managed forest landscapes. Our findings support the promotion of partial cut harvest as an effective strategy to achieve species and habitat conservation goals.


2004 ◽  
Vol 82 (6) ◽  
pp. 830-849 ◽  
Author(s):  
Mireille Desponts ◽  
Geneviève Brunet ◽  
Louis Bélanger ◽  
Mathieu Bouchard

The objective of this project was to assess the importance of pristine forests in maintaining the botanical biodiversity of the humid boreal balsam fir forest of eastern Canada. The study was based on a comparative analysis of silviculturally mature second-growth stands and pristine forest stands at two stages of development (senescent and old growth) in the Gaspé Peninsula. The structure and composition of the stands was described, and the abundance of structural attributes evaluated. The communities of nonvascular plant species (mosses, liverworts), lichens, and saprophytic fungi were compared. The study demonstrated that the pristine forest landscape studied was composed largely of old-growth and senescent stands. Old-growth forests are differentiated by their irregular structure. The results regarding nonvascular plant species, lichens, and saprophytic fungi show higher species diversity in old-growth forests, corresponding to higher habitat diversity. Species assemblages were comparable between the pristine forests, but different from those of second-growth stands. Rare species are found more frequently in the old-growth forests. The results indicate that the old-growth balsam fir stands of the Gaspé Peninsula constitute critical habitats for maintaining a large number of species threatened by the gradual disappearance of primeval stands.Key words: forest management, biodiversity, old-growth forest, humid boreal fir forest, nonvascular plants.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Akash Tariq ◽  
Muhammad Adnan ◽  
Naser M. AbdElsalam ◽  
Hassan Fouad ◽  
Kamran Hussain ◽  
...  

Pakistani Himalaya stretches over a wide range of altitudinal gradients and supports high diversity of medicinal plants that are an important source for rural livelihood. Altitudinal effects on ground vegetation have already been indicated but ground vegetation is also under severe threat of grazing and over collection. The present study investigated the effect of altitude on medicinal plants abundance in both old-growth and derived woodland forests. Each of the five line transects was selected in old-growth and derived woodland forests. Each line transect consisted of four plots distributed at four altitudinal levels (2200, 2300, 2400, and 2500 m asl). Species richness under derived woodland had shown strong negative correlation (r=-0.95) with altitude while it was found to be nonsignificant under old-growth. Cover of most of the species such asVeronica laxa(r=-0.95,P≤0.05) had shown significant negative correlation with altitude under derived woodland. Cover abundance of some species likeValeriana jatamansiand Violacanescenshas also shown significant negative correlation under old-growth forest. Derived woodland can decrease the cover abundance of valuable medicinal plants towards extension at higher altitudes. Thus, protection of the derived woodland could serve as a tool for the improvement of rural livelihood and ecological restoration.


2009 ◽  
Vol 85 (5) ◽  
pp. 762-771 ◽  
Author(s):  
Gordon M Hickey

The debate surrounding Tasmania’s old-growth forests in 2004 represents a good example of a situation where, despite both sides of a highly polarized policy field drawing on science to support their world view (to varying degrees), little common ground was found to enable robust and shared discussions that were required to resolve the conflict and collectively define a sustainable future for Tasmania’s old-growth forests. This paper reviews the scientific and policy-related literature on old-growth eucalypt forests and outlines recent developments in old-growth forest policy in Tasmania. It describes the highly polarized public policy debate surrounding Tasmania’s old-growth forests in the lead up to the 2004 Federal election, and considers the challenges posed by polarized democratic debate when developing public policy. It then considers the different dimensions of forest-related scientific knowledge and discusses the role of science in informing and resolving the polarized old growth debate in Tasmania. Key words: Sustainable forest management, strategy, politics, research, government, Australia


2003 ◽  
Vol 11 (S1) ◽  
pp. S79-S98 ◽  
Author(s):  
Karen Harper ◽  
Catherine Boudreault ◽  
Louis DeGrandpré ◽  
Pierre Drapeau ◽  
Sylvie Gauthier ◽  
...  

Old-growth black spruce (Picea mariana) boreal forest in the Clay Belt region of Ontario and Quebec is an open forest with a low canopy, quite different from what many consider to be "old growth". Here, we provide an overview of the characteristics of old-growth black spruce forest for three different site types on organic, clay, and coarse deposits. Our objectives were (1) to identify the extent of older forests; (2) to describe the structure, composition, and diversity in different age classes; and (3) to identify key processes in old-growth black spruce forest. We sampled canopy composition, deadwood abundance, understorey composition, and nonvascular plant species in 91 forest stands along a chronosequence that extended from 20 to more than 250 years after fire. We used a peak in tree basal area, which occurred at 100 years on clay and coarse sites and at 200 years on organic sites, as a process-based means of defining the start of old-growth forest. Old-growth forests are extensive in the Clay Belt, covering 30–50% of the forested landscape. Black spruce was dominant on all organic sites, and in all older stands. Although there were fewer understorey species and none exclusive to old-growth, these forests were structurally diverse and had greater abundance of Sphagnum, epiphytic lichens, and ericaceous species. Paludification, a process characteristic of old-growth forest stands on clay deposits in this region, causes decreases in tree and deadwood abundance. Old-growth black spruce forests, therefore, lack the large trees and snags that are characteristic of other old-growth forests. Small-scale disturbances such as spruce budworm and windthrow are common, creating numerous gaps. Landscape and stand level management strategies could minimize structural changes caused by harvesting, but unmanaged forest in all stages of development must be preserved in order to conserve all the attributes of old-growth black spruce forest. Key words: boreal forest, old growth, paludification, Picea mariana, structural development, succession.


Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 27
Author(s):  
Giorgio Brunialti ◽  
Paolo Giordani ◽  
Sonia Ravera ◽  
Luisa Frati

(1) Research Highlights: The work studied the beta diversity patterns of epiphytic lichens as a function of their reproductive strategies in old-growth and non-old growth forests from the Mediterranean area. (2) Background and Objectives: The reproductive strategies of lichens can drive the dispersal and distribution of species assemblages in forest ecosystems. To further investigate this issue, we analyzed data on epiphytic lichen diversity collected from old-growth and non-old growth forest sites (36 plots) located in Cilento National Park (South Italy). Our working hypothesis was that the dispersal abilities due to the different reproductive strategies drove species beta diversity depending on forest age and continuity. We expected a high turnover for sexually reproducing species and high nestedness for vegetative ones. We also considered the relationship between forest continuity and beta diversity in terms of species rarity. (3) Materials and Methods: we used the Bray–Curtis index of dissimilarity to partition lichen diversity into two components of beta diversity for different subsets (type of forest, reproductive strategy, and species rarity). (4) Results: The two forest types shared most of the common species and did not show significant differences in alpha and gamma diversity. The turnover of specific abundance was the main component of beta diversity, and was significantly greater for sexually reproducing species as compared to vegetative ones. These latter species had also the least turnover and greater nestedness in old-growth forests. Rare species showed higher turnover than common ones. (5) Conclusions: Our results suggest that sexually reproducing lichen species always have high turnover, while vegetative species tend to form nested assemblages, especially in old-growth forests. The rarity level contributes to the species turnover in lichen communities. Contrary to what one might expect, the differences between old-growth and non-old growth forests are not strong.


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