The tangled causes of population decline in two harvested plant species: a comment on Ticktin et al. (2012)

1. Ticktin et al. (2012) attempted to disentangle multiple stressors impacting harvested populations of amla (Phyllanthus emblica and P. indofischeri) [Ticktin et al. (2012) Disentangling the effects of multiple anthropogenic drivers on the decline of two tropical dry forest trees. Journal of Applied Ecology, 49, 774–784.]. 2. We propose that an unbalanced design and substitution of missing data for key parameters render their matrix models flawed. They conclude that the main threats to recruitment were lantana and mistletoe invasion and recommend revoking the ban on amla harvest. 3. Our re-analyses of their data set, without substituting unavailable data, showed that cessation of harvests significantly increased stochastic growth rates of amla, despite high lantana and mistletoe cover. 4. Management recommendations by Ticktin et al. (2012) were based on the assumptions of invasiveness of a native mistletoe and grazing impacts of wild ungulates. However, interactions with amla are complex, and the recommendations made by them could have deleterious repercussions on native biota. 5. Synthesis and applications. Developing an objective understanding of harvest consequences by incorporating earlier findings and considering uncertainties in results is critical for maintaining livelihoods and ecological processes linked to amla populations

Environment and Past Land Use Together Predict Functional Diversity in a Temperate Forest

Environment and human land use both shape forest composition. Abiotic conditions sift tree species from a regional pool via functional traits that influence species’ suitability to the local environment. In addition, human land use can modify species distributions and change functional diversity of forests. However, it is unclear how environment and land use simultaneously shape functional diversity of tree communities. Land-use legacies are especially prominent in temperate forest landscapes that have been extensively modified by humans in the last few centuries. Across a 900-ha temperate deciduous forest in the northeastern United States, comprising a mosaic of different-aged stands due to past human land use, we used four key functional traits—maximum height, rooting depth, wood density, and seed mass—to examine how multiple environmental and land-use variables influenced species distributions and functional diversity. We sampled ~40,000 trees \u3e8 cm DBH within 485 plots totaling 137 ha. Species within plots were more functionally similar than expected by chance when we estimated functional diversity using all traits together (multi-trait), and to a lesser degree, with each trait separately. Multi-trait functional diversity was most strongly correlated with distance from the perennial stream, elevation, slope, and forest age. Environmental and land-use predictors varied in their correlation with functional diversities of the four individual traits. Landscape-wide change in abundances of individual species also correlated with both environment and land-use variables, but magnitudes of trait–environment interactions were generally stronger than trait interactions with land use. These findings can be applied for restoration and assisted regeneration of human-modified temperate forests by using traits to predict which tree species would establish well in relation to land-use history, topography, and soil conditions

Feast at the Fig

56-57The soft golden hue of the early morning sunshine wafts through the canopy, bathing the evergreen forest in a honeyed hue. Spider webs gleam their intricate patterns like diamond dust on gossamer, as the dewdrops on them catch the first shafts of the morning light. The cackling “kok-koko-koko-kok” of the ubiquitous jungle fowl breaks through the early stillness, calling the forest to wakefulness

From Fungi to Forests: The Tale of Tropical Tree Diversity

Volume: 75Start Page: 25End Page: 3

Misconstrued dichotomies

[Extract] WE live in an age of trade-offs. In pursuit of material well-being, human societies are transforming earth's land and water in manifold ways, in the process compromising the very natural systems that are essential for our survival. The vast sprawl of homo sapiens across the planet is causing one of the largest extinction crisis – 1000 times higher than ever in earth's history. To burgeoning human numbers, add the societal imperative for economic progress and we certainly face a quandary. How do we ensure development for all people and yet safeguard vital ecological wealth and biodiversity on this finite planet? Equity being an essential prerequisite for sustainability, what measures can ensure resource use in the most equitable manner? In a populous country like India, seeking to maintain its economic growth potential while also preserving its natural wealth, these are questions of paramount importance

Post-logging recovery of animal-dispersed trees in a tropical forest site in north-east India

Selective logging is known to alter the structural and community composition of tropical forests and may disrupt plant-frugivore interactions. We hypothesized that even after a sufficient period of recovery, logged areas will not possess as complete a suite of species as an unlogged forest, the differences being more marked for biotically-dispersed species. Species of this functional group are expected to occur at lower densities, have lower species richness and diversity, and be smaller in logged forests. To quantify structural and functional differences in tree communities, we sampled 120 randomly placed plots, 60 each in logged and unlogged forest sites. We found significant differences in species richness and diversity between logged and intact forest. Within biotically-dispersed species, bird dispersed species showed a significant reduction in species richness. Consistent with previous studies, trees in logged forests were smaller, although overall density was not different between the two treatments. We posit that selective logging might have pervasive effects on functional aspects of tropical tree communities, which appear to persist even after two decades of logging cessation

Parks protect forest cover in a tropical biodiversity hotspot, but high human population densities can limit success

Maintaining forest cover is important for Biodiversity Hotspots that support many endangered and endemic species but have lost much of their original forest extent. In developing countries, ongoing economic and demographic growth within Hotspots can alter rates and patterns of deforestation, making it a concern to quantify rates of forest loss and assess landscape-scale correlates of deforestation within Hotspots. Such analyses can help set baselines for future monitoring and provide landscape-scale perspectives to design conservation policy. For the Western Ghats Biodiversity Hotspot in India, we examined correlates of forest loss following rapid economic expansion (post-2000 CE). First, we used open-source remote-sensing data to estimate annual trends in recent forest loss (from 2000 to 2016) for the entire Hotspot. Across the entire Western Ghats, we assessed the relative importance of and interactions among demographic, administrative, and biophysical factors that predicted rates of forest loss—measured as the number of 30 × 30-m pixels of forest lost within randomly selected 1 km2 cells. Protected areas reduced forest loss by 30%, especially when forests were closer to roads (33%) and towns (36%). However, the advantage of protection declined by 32% when local population densities increased, implying that the difference in forest loss between protected and non-protected areas disappears at high local population densities. To check scale-dependency of spatial extent, we repeated the modelling process for two landscape subsets within Western Ghats. In contrast with results for the entire Western Ghats, both focal landscapes showed no difference in deforestation with protection status alone or its interactions with village population density and distance to towns. However, deforestation was 88% lower when forests were protected and farther from roads. Overall, our results indicate that protected areas help retain forest cover within a global Biodiversity Hotspot even with rapid development, but high human population densities and road development can reduce the benefits of protection

Sidestepping Science: India's 'Notional' Board for Wildlife

The Narendra Modi government's initial reconstitution of the National Board for Wildlife, which the Supreme Court questioned as contravening the provisions of the Wildlife (Protection) Act, is in line with the current ethos of development at all costs. The decision to keep out domain experts in ecology suggests a refusal to acknowledge the complexities underlying conservation