Saving the Halle Hemlocks & Encouraging Biodiversity

Fall 2022

Message from our Land Steward:

Love walking in Halle Ravine? Then you should thank the eastern hemlock tree! They are the reason for the cool shade in the summer and the continued green foliage in the depths of winter. These trees are the foundational species upon which the entire ravine ecosystem depends. They thrive on steep ravine banks and hold the soil together, lower water temperature for aquatic life in the heat of the summer and provide critical overwintering bird habitat. Their fallen trunks are the growing location for most of the mosses in the ravine. 

There are over 1000 eastern hemlock trees along Halle Ravine, and they are under a death threat from a tiny killer – the hemlock wooly adelgid. This invasive pest sucks sap from the base of hemlock needles. When thousands cover a single tree, they will literally suck the life out of it. Their population density can be estimated by looking up and observing the amount of fussy white spots lining the underside of the branches; each spot being the protective covering of a single adelgid. 

In 2017 and 2018, with your support and a grant from the Westchester Community Foundation, PRLC treated 211 hemlock trees and it worked. As of March 2022, treated trees increased their needle density by an average of 33% with a 12% average increase across untreated hemlock trees, showing a net benefit throughout the preserve. More cones are also being produced and we have observed hemlock seedlings growing. Now these trees need your help again. To continue this upward trend, retreatment needs to occur after 5-7 years, placing 2023 as the critical year in which action needs to be taken. 

Destruction of an entire tree species from invasive pests and diseases is becoming all too common for us in Pound Ridge. The American chestnut and elm are largely trees of the past. Ash trees are nearly extirpated from our region and are facing possible extinction across its range. Beech trees are under threat with no known treatment and could be next. But hemlocks. HEMLOCKS WE CAN SAVE! While regionally less common, being restricted to mostly ravine type topographies, the eastern hemlock is the third most common tree species in New York state and a dominant component of the entire northeastern forest. Losing these trees would be disastrous on an unprecedented scale and we can do something to prevent that. YOU can do something to prevent that. Donate to PRLC today, dedicating its use for treating the hemlocks at Halle Ravine and you will help preserve a local treasure and an entire tree species. We need to raise an estimated $40,000 by May 2023 to treat our goal of 400 trees. Please help save the hemlocks at Halle Ravine!

-Andrew Morgan, Land Steward, PRLC

President’s Message

On November 1st we added our twentieth preserve, the Yaggi Biodiversity Preserve. It is a 3-acre plot on Hack Green Road, adjacent to the 3.5-acre De La Torre Preserve and more than 200-acres of Aquarion land. The photo shows Andrew Morgan atop one of the gigantic glacial rocks on the property. The preserve was donated by Marc Yaggi and his wife Sara Douglis. Marc is the CEO of Waterkeeper, the worldwide association of Riverkeeper organizations. Sara is on the board of Bedford 2030. Here’s a huge thank you to Marc and Sara for their generosity!

When an important conservationist such as Marc asks to name the preserve the “Yaggi Biodiversity Preserve” it is worthwhile to consider why Marc wants to emphasize the importance of biodiversity. The UN declared at its 2021 Biodiversity Conference that the current enormous species die off, one of the six worst such events in the history of our planet, is as great a threat to human life as rising carbon dioxide levels. The science is clear that the more species in a given area the more resistant it is to climate change. In the 600 million years since the emergence of multicellular life, our planet’s average temperature has remained in a narrow band around 70 degrees despite a 25% increase in the energy reaching earth from the sun. Life acts as a buffer to keep the temperature near 70 degrees. If too many species die we risk a temperature runaway. 

What can we do about it? We can remove invasive and non-native plants and restore with natives. We can protect threatened keystone species such as the hemlocks at Halle. We can reduce the size of our lawns and replace with natives, even a meadow if you have that much space. We can stop using herbicides and pesticides and unnecessary fertilizers. We can use fallen leaves for mulch. We can leave dead trees alone as they are great habitat for insects.

And we can also permanently preserve land. The theme of the 2022 UN Biodiversity Conference is the goal to preserve 30% of the land in the world. Marc and Sara donated their land to the PRLC to promote biodiversity. We are blessed in Pound Ridge to have the highest percentage of permanently preserved land in our region, over 50%. H2H the regional association of land conservancies considers Pound Ridge to be the most biodiverse and the most climate resilient town in Westchester. 

Please consider donating your land or to one of the other conservation organizations in town – especially if it is adjacent to already preserved land. We worked with the Yaggi’s to maximize the tax donation for their deduction and would be delighted to do the same for you. Conservation easements are also a way to preserve land without giving up title. 

The PRLC has long depended too heavily upon a limited number of large donors to fund our efforts. In order to ensure that we can preserve the land we own forever, we need to diversify our base of supporters. You already know that the work of PRLC is important. Many of you are already member-supporters. We need all of you to renew your membership today, with your tax deductible contribution at whatever level you can afford. If you have not previously contributed, we urge you to do so now, and become a member of this vital organization. All of our efforts - to protect native plants, to maintain our kiosks, bridges and trails, to purchase and install signage for your education and enjoyment, and more – cost money. PRLC has an all- volunteer board, but we still have expenses. We are entirely contribution supported, with assistance from our grant partners for specific projects, and we need your help. Please give as generously as you can!

-Mike Kagan, President, PRLC