Reclamation - restoring disturbed lands

Another article on a familiar story.

Two decades ago Knepp was a debt-ridden, subsidy-dependent farm.

The UK government-funded research found that the rewilded soil absorbed up to 4.8 tonnes more carbon dioxide per hectare per year than soils in a conventional farm close by.

Knepp's soil data is the first to show that rewilding a farm can lead to statistically robust carbon sequestration in soils.

"It's wonderful to have projects like Knepp producing the credible evidence that can help to convince policymakers that this is a viable way forward," says Alister Scott , director of the Global Rewilding Alliance.

Tree hopes the research will help secure a seat for rewilding at the carbon market table, as so far there are no investment products or market mechanisms that support rewilding.

Rewilding has the potential to address both the climate and biodiversity crises, according to Scott with Global Rewilding Alliance.

Galán Díaz and colleagues found that invasive species had other advantages.

Coloniser species displayed longer bloom periods, allowing them to be receptive to visitors at times that didn't only match pollinator activity in their home ranges.

These coloniser species brought novel traits into the recipient communities, such as annual life cycles and efficient resource-use strategies, highly beneficial in a context of farming, intense herbivory, long drought periods and high soil disturbance.

Both types of colonisers - invasive and naturalised - exhibit similar levels of climatic richness, but invasive species show a greater level of climatic diversity.

The botanists noticed some critical differences between coloniser and non-coloniser species regarding specific characteristics.

Using a kind of statistical analysis called 'random forest modelling', Galán Díaz and colleagues were able to predict whether a species is a non-coloniser or coloniser with an accuracy of over 73%. Variables, including climatic niche richness and the number of seed-dispersal mechanisms, were crucial to these predictions.

They conclude: "The knowledge derived from such studies may allow us to improve prediction models, identifying key species to monitor; this could prevent potential harmful impacts from coloniser species in invaded communities and reduce the investment necessary to target eradication measures."

cross-posted from: https://aussie.zone/post/989078

Groundwater impacts vegetation and the atmosphere via the soil-plant-atmosphere pathway.

Groundwater therefore contributes to the flows of water, energy and carbon between the land and the lower atmosphere and can influence local and regional air temperature and perhaps precipitation.

Understanding the potential impact of groundwater dynamics on climate extremes is an urgent topic of research given projections of more heatwaves and droughts in the future.

During heatwaves, groundwater reduces forest canopy temperatures by up to 5°C, where groundwater is shallow. However, the cooling effect is limited to the first two years of the multi-year droughts. The groundwater cools the forest canopy in heatwaves only 0.1~0.3 °C at the end droughts.

cross-posted from: https://aussie.zone/post/989457

This person posts about native plantings and animals on their property. They do a lot of work and the photos are helpful in seeing the changes. The blog is recommended.

Summary of the latest post:

Over the last year, I did not record any new amphibians, reptiles or mammals on our property, and a brief visit by a Zebra Finch constituted the only new bird.

Throughout the year, we didn't receive a single rain event large enough to generate runoff to fill our creek and dam.

Due to the dry summer and autumn, I only managed to get 295 new trees planted this year.

Over the seven years, I have planted a total of 3,350 trees, shrubs and vines, comprising 208 species of locally indigenous plants.

Last year's plantings were highly successful, courtesy of the wet autumn and winter of 2022.

Without any additional watering from me, I achieved a survival rate of 91.1%, which is the second highest of the seven years.

Some attendees had visited the property one or two years previously, so were more cognisant than I of the changes over time

cross-posted from: https://aussie.zone/post/989239

With value measured in cows, we would struggle to make a living from Thiaki even though rainforest was among the most biologically valuable pieces of land in the country.

The nearest town is Malanda, 15km to the north by road. While it hadn't been easy to turn lush tropical rainforest into paddocks - some individual settlers worked at it for decades - how could you turn paddocks back into rainforest? Local efforts on the Atherton Tablelands to restore degraded land back to rainforest were heroic but ad hoc.

Work commenced apace to design the reforestation research plan for the foundations of a brand-new rainforest that uses different mixes and numbers of native species with different planting densities.

On 28 January 2011, a bunch of academics and a crack team of planters with dirt under their fingernails and dreadlocks like flowing lianas, assembled to build the foundations of a rainforest with 30,000 plants, and to create the conditions for a phoenix to rise once more from the ashes.

The clearing frenzy of the first 20 years of the 20th century brought about the near extinction of the upland rainforest on the Atherton Tablelands.

https://www.sciencedirect.com/science/article/pii/S0301479723004334

• Reforestation success can be improved by enhancing tree planting methods
• Low sapling survival rates lead to high replacement costs and can hinder reforestation efforts
• Damage to fibrous roots during handling affects sapling survival
• Initial soil properties and conditions have a greater impact on sapling survival than adult traits
• Careful planting methods result in better sapling survival rates in the longer term
• Factors such as seedling survival, root growth, and seedling quality play a significant role in tree establishment
• Non-native grass removal and shade increase soil moisture and seedling performance during forest restoration

Four years ago, we put down a first instalment on half a hectare of pasture in Altamira which had been degraded by fire and years of grazing cattle.

Unlike the vast majority of settlers in this region, we prefer living in semi-forest rather than cleared land because the trees provide shade, we think it is more beautiful and it feels healthier.

By the second year, the plot looked more like a head-high shrubbery, speckled with bright red seed pods.

An investor in a reforestation scheme needs to know that trees will be left to do what comes naturally without human interference.

I will nurture those solutions like my plants, more in hope than expectation, with one eye on the weather and one eye on the news.

Giant tortoises reintroduced to Galapagos' Española Island are engineering the ecosystem by reducing trees, aiding cactus regeneration, and creating nesting grounds for the waved albatross.

A new study published in Conservation Letters by Tapia Aguilera & Gibbs provides evidence that reintroducing giant tortoises to Española Island in the Galapagos archipelago is transforming the island's plant communities.

They've since been a conservation success story, with over two thousand tortoises reared and released on the island, but what effect are they having on their habitat?

The study's findings suggest that trophic rewilding programs involving megaherbivores like tortoises could help restore critical ecosystem functions on islands where native species have been severely reduced.

"Tortoises consumed virtually every cladode that fell to the substrate. This would effectively eliminate vegetative reproduction in cactus Similarly, tortoises consumed almost all cactus fruits deposited, which would greatly expand the scope for seed dispersal away from the parent plant, where bird predation on seeds is most intense. We expect that seed dispersal by tortoises provides a critical vector for sexual reproduction in cacti, resulting in more cactus recruits in the larger landscape, whereas intense consumption of cactus parts by tortoises renders asexual reproduction by cactus inviable."

Tapia Aguilera & Gibbs conclude that, for Española Island, rewilding with Giant Tortoises has been a success, but caution against assuming that the circumstances here apply everywhere.

The soil particles become so closely packed together, the soil can't absorb water."

"A single teaspoon of healthy garden soil can hold up to one billion bacteria, several yards of fungal filaments and hundreds to thousands of microscopic lifeforms such as protozoa and nematodes," says Akshit Puri, also of the Faculty of Land and Food Systems at UBC. Earthworms and arthropods add nutrients to the soil through their waste.

Soil microorganisms are physiologically active in moist soil but dormant in dry soil.

It will take time for the boulevard soil to be revived to the point that it's equal to healthy garden soil.

The Soil Science Society of America notes that it takes hundreds of years for soil to naturally form and become fertile.

Is Semlacher making progress? No longer beige and ecru in hue, the boulevard soil is now that dark milk-chocolate colour quintessential to living soil.

Or maybe, like Alice's Adventures in Wonderland, I was drawn back to childhood, where with a little imagination, nothing's impossible, even restoring the most precious commodity of all - soil.

A Griffith University-led project is working with Soloman Island communities to test different ways of restoring forests to benefit local residents and revitalise ecosystems.

The Livelihoods in Forest Ecosystem Recovery project is helmed by Griffith's Centre for Planetary Health and Food Security Director Professor Helen Wallace for ACIAR, who said there was a critical need to find ways to restore the forests in Solomon Islands.

LIFER is a six-year project that began in January 2023, building on a pilot project funded by the US Forest Service on Kolombangara Island.

• Treatment 1 will serve as the control, with protection but no active effort to restore the forest.
• Treatment 2 is ‘assisted natural regeneration’ where weeding and thinning, for instance, will be used to help valuable species re-establish themselves.
• Treatment 3 is ‘enrichment’ and includes management activities and replanting trees that communities have identified as important for future use.
• Treatment 4 is a more intensive ‘agroforestry’ approach, with substantial planting of timber species, along with other useful tree and food crops.

Professor Wallace said the first steps involved talking to communities about how they use their forests and what they want and need from future forests.

The LIFER project will fund participating communities to maintain the trial sites during the life of the project and to help monitor tree growth, biodiversity and livelihood benefits.

"We really want to empower local women and give them a voice in forest management and promote leadership in forest governance. This will include working with the National Council of Women," Professor Wallace said.

"We found that there's a strong link between the species diversity of tree habitats and the population density of the spiders that live in them," said Karin Burghardt, senior author of the study and assistant professor of entomology at UMD. "Spiders really like complex habitats, so having a large variety of tree species with different structural features like height, canopy cover and foliage density will help increase spider abundance and also the natural pest regulation they provide."

"There have been some large-scale tree diversity experiments conducted in Europe and Asia, but our study is one of only a handful of experiments of its kind in temperate North America," Burghardt said.

On the plots, the researchers planted the same tree species or four or 12 different tree species.

After repeatedly sampling 540 trees in these plots by counting the number of spiders found in each tree, Burghardt and her team found that plots with higher tree species diversity also hosted greater spider populations.

By the end of the project in 2021, plots containing four or 12 different tree species supported approximately 23% to 50% more spiders than single species plots, due to their cooler, shadier conditions.

"Plots with more variation in tree species tend to have more canopy cover than plots with only a single tree species," Burghardt explained.

The researchers found the strongest relationship between tree diversity and spider populations during the late summer months when average temperatures were at their highest.

cross-posted from: https://aussie.zone/post/683314

In a multi-generation experiment, researchers from the College of Agricultural, Consumer and Environmental Sciences found microbes helped plants cope with drought, but not in response to plants' cries for help.

To learn how microbes help plants deal with drought, Ricks established live soil communities in pots with or without plants.

He again grew plants in soil from phase one and kept the same watering treatments, but some plants were now experiencing drought in soils that had been well-watered for generations, and vice versa.

He expected soil microbes from historically dry pots would have adapted to those conditions, helping plants withstand drought more than microbes from historically wet pots.

Ricks said soil microbes are involved in many processes that could help plants withstand stress.

cross-posted from: https://aussie.zone/post/683320

Tree planting is a central plank in Britain's net zero strategy.

An inability to get new woodland established means the UK will almost certainly not meet carbon sequestration and biodiversity conservation targets.

The environmental audit committee report identifies several failings and bottlenecks to progress with woodland creation.

One way of reducing complexity would be to give greater autonomy to tree and woodland professionals.

Giving chartered arboriculturists and chartered foresters greater independence, supported with a simpler funding model, could help incentivise and liberate tree and woodland professionals to do what they do best, which is create and manage the UK's valuable woodlands for both people and nature.

cross-posted from: https://aussie.zone/post/640043

More consideration should be given to animals in ecosystem restoration assessments and a new CDU study shows how this can be done. According to CDU Research Institute for the Environment and Livelihoods ecologist and lead author of the study, Professor Alan Andersen, specific standards are required for assessing how well animal communities have been restored.

“It is important to include a wide variety of animals, not just because of their intrinsic biodiversity value but also because of the many ecological roles they play in restoration processes.

However, up until now there has been no framework for doing this.” But Professor Andersen said the assessment framework can be applied to any ecosystem worldwide.

“Specific standards of evaluating returning animal populations can be set to suit any level of restoration, no matter where it is,” he said.

Good intentions in ecological restoration can sometimes result in the unintentional spread of plant diseases due to neglected risk assessments and biosecurity measures.

Ideally, ecological restoration will help heal a habitat, but when you bring back plants to a location, what else are you bringing along? According to researcher Ruth Mitchell's study published in Restoration Ecology, the well-intended act of introducing flora might also inadvertently spread plant pests or pathogens, potentially causing more harm to the ecosystem and biodiversity than anticipated.

Mature plants act as a "Biological package", housing not just the plant itself but any organisms living on it or within the surrounding soil.

There is thus a balance to be achieved between ensuring greater awareness of the plant health risks and not burdening low-risk ecological restoration projects with unnecessary biosecurity measures, which become a barrier to "Bending the curve for biodiversity" and mitigating the biodiversity crisis.

What was intriguing was how participants perceived the potential impact of plant pests on biodiversity to differ between habitats.

Regarding risk assessments and biosecurity practices, more than half of the participants were unsure or did not know if they had a risk assessment for plant pests.